About me
Hi Everyone,
This is Naga Pavan Kumar (people remember me as pavandba)
Being born and brought up in vijayawada as only son to my parents, I used to be very calm going boy at the start of every academic year and most craziest boy at the end.
After completing my X std education in T.K.S.V.Lions school (don’t ask for abbrevation of T.K.S.V, i forgot long back !!!), and XII std (Intermediate) in Vijaya Krishna Junior College, my father forced me to complete my Engg from Jerusalem college of Engg, Chennai so as to see how the world is…. ( I had not been to any place since my childhood and i realized that this is the reason in my Father’s thoughts)
2004, year which tagged a B.Tech (IT) degree to my hand and throwed me to the world of competetion and asked me to survive.
After a struggle for 1 yr, I am here as Oracle DBA with a minimal knowledge and experience. Daily I feel to dig lot of things in DBA.
This Blog is intended to share my minimum knowledge to others
I have been active EXPERT member in Oracle Forums. Right now, I am working as Operations Manager for Oracle DBA team and as Database Architect in a MNC.
As I love Oracle DBA so much, same I love to watch Movies. Many stories builded from my mind, hope some day I will hold megafone.
I dedicate this blog to my mother VIJAYA LAKSHMI and father MURALI KRISHNA, who were always been there to build me as successful man.
Last but not least, I want to dedicate this page to my wife who have been always with me in understading my passion towards Oracle DBA.
About a year back, wonderful angel DHRUVI occupied our lives and now all the time is set for her to play with me. Still been trying to post new things I am learning
Here are some of my certifications
Pavan DBA's Blog 
Harmeet Singh said
Hello Pavan,
I have not seen as many comments as I see here. I am a DBA, started career in Oracle and then due to migration had to switch to SQL Server. Now I am planning to move back to Oracle, suggest me a good site or Blog where I can refresh things again. Its been more than 2 years I am out of touch with Oracle.
Pavan DBA said
Hi Harmeet, thanks for your words. for refreshing, i would say always it is best to read oracle documentation or read books which are available in google. also, there are plenty of videos available over youtube which gives knowledge on latest versions.
Melinda Sosa said
Hi Pavan,
I am an accidental DBA with a modest, but constantly growing skillset. On several occasions I have searched the internet and other resources for days for solutions to various ora- tns- errors. The answers all seem the same, very general and superficial and did not solve my problems. On those occasions, I have eventually found myself on you site, where I find solutions that work. I appreciate your explanations, they are thoughtful and complete. I am making you my first resource!
Peace,
misosa
Pavan DBA said
Thank you very much for your kind words and really happy that my little knowledge is helping you
munir said
hello sir
I’am currently teaching oracle 11g administration in delhi,how can I get a full time job in database industry as a dba.Is there any job available for me,I’am a B.Tech in CS with good working knowledge in oracle
Pavan DBA said
which year have you passed out?
Dinesh Chandra said
Hi pawan,
I am an Oracle DBA and want to join RAC course.
Do you provide class room training ?
If yes then please mail me on ” gunwant.dinesh@gmail.com “
Pavan DBA said
plz contact admin@thetechmaster.in for all training related queries
Ram said
Hi sir,
sir aap ki guidence chayie thie…sir mujhe oracle dba bna h..mujhe oracle ka kuch nhi ptha h..to m first step kha s start kru.pls guide me
Pavan DBA said
hi, u need to do oracle dba course from any good institute.
oracle said
I have a full database backup with archive log all till 17 May 2015 Now team want to restore the database with 13 May 2015 only with the help of 17 May 2015 full backup then how we can restore back date Pls guide.
Thanks
Pavan DBA said
you need to choose recover until time option. there you can give date and time what you required.
Amit Kumar Yadav said
Hi Pavan ,
Could you please help out for below queries .
Difference Between OLAP & OLTP at hardware level ?
How will come to know at schema level difference between OLAP & OLTP ?
Do we have any Parameter which can be a differentiation for OLAP & OLTP ?
Can we create OLTP & OLAP instance in same DB ?
Pavan DBA said
Hi Amit,
SGA and PGA memory allocations will be different for OLTP and OLAP. Hardware level there will not be much difference.
at schema level, we cannot identify really but transactions wise, yes there will be. there is no such single parameter to know if it is OLTP or OLAP. if you can know what is the application functionality, then you can confirm on it.
yes, we can create same db to act as both OLTP and OLAP.
srinivas rajnikanth said
hello sir currently am working as a web designer.but am intrested in oracle so wish to learn !are you offering placement also
Pavan DBA said
there will be no gurantee on placement. will provide only placement assistance
Prasad said
hi pavan,
this is prasad.i have completed MCA in 2004. but i am working as a DBA in non-IT organisation. i have no knowledge on DBA roles. so i need training on oracle DBA in vijayawada. kindly help us.
Pavan DBA said
plz send mail to mymailbox.21@gmail.com for those details.
chandan said
can we configure/install oracle RAC in a company’s test environment for testing? if yes, does oracle charge for the this configuration/licensing. Appreciate your suggestion/s before making taking any decision.
Pavan DBA said
u can install it. until unless u dnt contact oracle support for any help, it is fine to install and test
prasad said
Hi sir,
I am prasad completed B.Sc in 2010 , I would like to start carer in oracle DBA pleas suggest me it’s right decision or not.
Pavan DBA said
yes you can do that
subhan said
Hi Sir,
My self I am Subhan Completed Btech In 2014 , Is it better to do Oracle DBA course as my side because as i am from 2014 batch..If i complete the oracle DBA course will be there any opportunities for me to get the job..
waiting for your reply sir
Advance thanks
Subhan
Pavan DBA said
openings will be less for freshers, but if u can do oracle RAC also then u may get better chances
Satya said
Hi Pavan,
Appreciate for your time and response to our queries.
I have not done any certifications yet! I am preparing for OCA 11g and searching for latest dumps of OCA 11g, But Oracle keeps changing the questions after every 2 months. So can you please suggest how can I get the latest dumps of OCA 11g. Please send the dumps to my mailid – psndba@gmail.com.
Thanks in advance.
Satya.
Pavan DBA said
hi satya, i don’t have any dumps. i cannot help on this.
Namrata said
Hello Pavan,
Hope you are doing fine. I have one query regarding Data Guard. Oracle version is:11.2.0.3
How can we sync our primary and standby database automatically?
Thanks in advance
Namrata
Pavan DBA said
by default it is automatically synced only.
Pavan Kumar said
hi pavan i would like to know are you teaching now a days, if yes please please provide me the details so that i can join asap my mail id is pammi.boinpalli@gmail.com
Pavan DBA said
nope. i am not giving training now.
srikanth said
hi pavan sir
i am srikanth i am just started my career with oracle dba what is most asked for oracle dba in real time how can i start with dba
Pavan DBA said
u can do by taking training. plz contact corporate@dbatalent.com
Nick Arthur said
Hello ,
My name is Nick. I am the Sr. IT Recruiter at Pull Skill Technologies Inc (Pull Skill). I have identified your resume online and thought you might be a good match for this requirement! If you are qualified, available, interested, or planning to make a change, please reply to me via email with your most current resume attached. Kindly include a daytime phone number where you can be reached.
However, only you know if the position is the right position for you. Would you be kind enough to review the job description and let me know what you think?
Senior ORACLE GOLDEN GATE RESOURCE experience
Phoenix, Arizona
Duration- 6 month contract LONGTERM
I need someone that has expert level experience with Oracle GoldenGate, Oracle data guard and Active Data guard, supporting local and geographically dispersed HA.
· GoldenGate 11g and 12c.
· Zero downtime upgrades and migrations
· GDHA
· OEM Monitoring
· Veridata Expertise required.
· Data Guard and Active Data Guard.
· Homogeneous and heterogeneous replication strategies.
· Architecture, Engineering and operations.
On SITE, starting immediately.
————————————————————————————————————————————
:: Thanks & Regards ::
————————————————————————————————————————————–
Nick Arthur | Sr. Talent Acquisition Specialist | Pull Skill Technologies Inc.
Direct: 201.497.1010 X 106 | Fax: 201.641.0110
New Jersey | Illinois |www.pullskill.com | nick@pullskill.com
————————————————————————————————————————————–
pavan said
I am not interested. Thanks for asking.
Jayaraj said
Hi Pavan,
We have a project to setup 3 Node Oracle 11G R2 RAC on RHEL6.X and do a migration of the Databases from old RAC on 11G R1. Could you please direct me to any good consultant we can take up the project, we can offer a decent fee for the task.
regards,
Jay
+91998917877
Pavan DBA said
is this project still open?sorry didnt saw ur msg as i am busy
Simli said
Hello Pavan sir,
I have one query regarding DBA_REGISTRY. What to check in DBA_REGISTRY view?
Any help will be highly appreciated.
Thanks and regards
Simli
Pavan DBA said
it will tell u what components of oracle database are installed and active in your database.
Arun said
Hai Pavan,
Iam Arun kumar was completed B.tech in 2014. Now iam working in Software company in .NET technology. I like to study Oracle DBA. I doesn’t programming jobs. Oracle DBA have good future for me???
Arun said
SqlStar is good training institute ?? in chennai
Pavan DBA said
hi arun, sql star is good because it is authorized training center for oracle corp.
Pavan DBA said
yes u will have good future.
Arun Kumar said
I have finished my Oracle DBA training in Sqlstar. Now search job in oracle DBA. Iam have 6 months experience in development. For oracle dba jobs whether they will consider my development experience or not??. What are Topics mostly covered in fresher oracle DBA? Whether Oracle DBA jobs can be overcome by automation in future???
Pavan DBA said
all topics are imp
Dhivagar said
Hi Pavan,
Im currently working as a Oracle Apps Developer
Im interested to change my path to (Oracle Apps DBA)
Whether this course will be very helpfull in future and can i know wat will be my package if i shifted to Oracle Apps DBA
Pavan DBA said
yes it will be helpful. package depends on lot many factors but avg for 3 yrs exp u can get max of 5-6 LPA
Amol said
Hello Pavan,
I have been searching for a while now, for 11gR2 RAC dumps..(OCE)..Can you please help me with the same..
Pavan DBA said
sorry I don’t have them.
khater ali said
Hi Pavan,,
Can you share me oracle 12C OCP upgrade dump from 11G If you have
Pavan DBA said
hi ali, i don’t have them.
rajagopal said
Hi Pavan,
I am into testing field and want to move to oracle dba. can i shift to oracle dba as i was working daily on database as a database tester. i am having 6yrs experience in testing. Please reply at the earliest.
Pavan DBA said
yes u can. just take the dba course and then you can plan for moving.
Vijaya Kumar said
Hi Pavan,
Thanks to share all your experience to get exposure in dba for freshers also experienced persons. I have some queries regarding the database Performance. Please check the below issues. Give me the suggestions to get some clarification on the issues.
1. which parameters have to increase for sga_max_size is too low error and why you are getting error?
2. how will you take stackpack report and how to check the issues in that report and how to resolve the issues in that report?
3. after the recovery complete using rman backup why you are getting system tablespace not exist error?
4. if user say their query is taking more time to complete than before hw will u analyze and hw u will resolve the pbm ?
5. how will you set recovery strategy for 24 hrs data loss if cleint asked ?
6. how will you set recovery and redundancy for 24hrs data loss?
It is little bit urgent pavan. please give the reasons and solutions for the above queries.
Thanks in advance
Vijay.
Pavan DBA said
1. u shld increase sga_max_size and then sga_target
2. u need to run spreport.sql. for details steps refer oracle documentation. for analyzing read below
Click to access statspack_opm4.pdf
Click to access statspack_tuning_otn_new1.pdf
Click to access opdg_slow_database.pdf
3. I never got tht error. if u get it, plz send me details
4. https://community.oracle.com/message/1814597
5. u should set recovery window of 2 days
6. same ans as above
vamsi said
Hi Pavan
can you briefly share your upcoming batch schedule, Im looking for core+apps with RAC training. Also please share the syllabus and duration of training. please share fee details as well. here is my emal id vamsi.0960@gmail.com
Pavan DBA said
hi vamsi, for all kind of batch details, plz contact kanna technologies. email id and ph numbers r posted in my blog already.
uday said
Hi Pavan,
I am Udayteja. I got some doubt with RMAN>backup database plus archivelog;
RMAN>backup database plus archivelog all; [ It’s not working why? what is the reason]. could u plz tell me this pavan.
Pavan DBA said
when using that command, u dnt need to give archivelog all. its the syntax error. that is why it is not working.
Ravi said
Hi pavan,
I am ravi. i got confusing with these 2 questions?
1. When does the rowid will get changed?
2. Does the rowid get changed after we perform ;alter table table_name shrink space compact?
Pavan DBA said
1. when we use alter table move command or wantedly through application if we change rowid, then only it will change
2. rowid will not change when we use shrink commands.
Kishore Kolla said
Hi Pavan,
is there anyway to increase the size of Home Directory after installation of linux?
while installing oracle showing required home directlry space not available……
Pavan DBA said
yes. but i am not sure about commands. usually unix admin will do that.
Sathish said
Hi Pavan garu
I am new to oracle dba can you please clear me the below questions
1) What is the difference between Bitmap and btree index?
2) What is the difference is between physically stand by and logically stand by?
3) What is the difference between SGA Max size and SGA Target size?
4) What is the use of gather stats?
5) Why we put database in begin backup mode?
6) How to change SGA size from OS level?
please give me the answers to the above questions sir
Pavan DBA said
hi sathish, infact for all ur q’s u can get answers from google. but i will try to give one line answers
1. btree index should be created on high cardinality (no. of distinct values is called as cardinality) and bitmap index should be created on low cardinality columns. btree will store data in tree format and bitmap will store in table format
2. in physical standby database will be in either mount/read-only state. in logical standby, database will be in open mode.
3. sga_target will define what memory size oracle should consume from ram during db startup. sga_max_size will specify what max size it can use from ram.
4. optimizer will generate correct and best execution plan if the stats of the table are upto date.
5. to take backup. i had posted an article already in my blog. check that
6. u need to change kernel parameter called shmmax.
Kishore Kolla said
Hi Pavan,
when im running /.runinstaller
“First result : All installer requirements met.
Next result:
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2014-03-15_11-06-49PM. Please wait …[oracle@oraclehost database]$ Xlib: connection to “:0.0” refused by server
Xlib: No protocol specified
Exception in thread “main” java.lang.InternalError: Can’t connect to X11 window server using ‘:0’ as the value of the DISPLAY variable.”
Pls help me in this scenario.
Pavan DBA said
run this as root user n then try runInstaller
# xhost +
Kishore Kolla said
Hi Pavan,
i run “xhost +” from root user and immediately i got the error as follows
“access control disabled, clients can connect from any host”
Pavan DBA said
hi kishore, this is not an error. its a information message. it means now you can invoke runInstaller.
pratheek said
Hi Pavan Garu
Due to some power fluctuation at client side the production database is down. the client wants to set the dataguard (physically standby) environment as a primary database.
how we can do this. please give me the solution for this
Thanks
Pratheek
Pavan DBA said
you need to do failover. for steps refer google or my blog
Ravi said
Hi Pavan,
I am Ravi i have done dba course in Kanna 6 months back. Recently I have one question in an interview which is,
1. If the database size is small how do u migrate to other server?
2. If the database size is huze how will do u migrate to other server? Plz help me how do we do that.
Pavan DBA said
1. it is using expdp/impdp
2. using rman (if same OS and bit version on other server)
purnima said
Hi, it is now possible to migrate using rman convert command even if the OS and the Endian formats are different.
Pavan DBA said
yes. if u r using rman transportable tablespace option
kishore said
Hi Pavan,
I would like to know when is the next batch for oracle DBA classroom traning will going to start. please let me know then i can arrange myself to come to hyderabad as im from chennai.
Pavan DBA said
hi kishore, my next batch date is not yet confirmed. but it would be a online batch rather than classroom batch.
pratheek said
Hi Pavan garu,
i have one doubt, is there any possibilities to migrate data from 9i(9.2.0.7) to 11g(11.2.0.10). if possible please suggest me.
Thanks
Pratheek
Pavan DBA said
if it is between servers, then export/import is the only way.
Ashutosh Rathi said
Hi Pavan,
your blog gave lot of information about database. Even I want to build my career in database. I know SQL very well and started learning PLSQL, please suggest me what should I do after that to become a DBA.
Thanks & Regards,
Ashutosh Rathi
Pavan DBA said
you need to attend dba course from a good institute where they teach good concepts and in real time mode.
siva said
Hi Pavan sir,
I am shiva, i am ur student. i have got one question in an interview which is, I have one primary and standby. one of the archive is deleted on primary and there is a gap between primary & standby how do u fill the gap between both? plz tell the in this situation what we willl do ?
Pavan DBA said
hi siva, we need to take incremental backup on primary and we need to apply on standby.
Arun said
Hi pavan,
your blog is really awesome and informative. I have suggested many of my friends who are DBA to instead of going to google they should look into blog for there answers. It is very informative and like a ocean. Really an amazing blog. Many congratulations.
I have a query. Actually I am working a manual testing engg for last 4 yrs. Prior to that I have worked with BPO and KPO. can i change my line/profile ..i mean can i start my career as Oracle DBA?. Will i be taken as fresher? will age be an issue for campanies? do you take online classes for Oracle DBA beginners and what all prequistive is needed from my side. Looking forward for your reply. Thanks
Pavan DBA said
Hi Arun, first of all thanks for your words about my blog. but, really this is not more than google. i am sharing very little knowledge i know.
regarding your question, yes surely you can change your line to oracle dba. usually when you change your career path, they might treat you as a fresher in technical, but still process wise you are treated as experienced. also, if you can show the skill set in dba which an exp’d dba can perform, then usually companies don’t have option to reject. age will never be an issue for the companies.
reg classes, yes i do take online classes. but as of now i am dealing with a classroom batch. once it is finished (expecting it to complete by march end), then only i can start online batch. usually sql basics and unix basic commands are the pre-requisite for learning dba. but we do teach them for first 15 days in our course itself.
siva said
Hi Pavan sir,
I am siva. i have a small doubt which is, whenever we create a database using DBCA, the data block size is 8kb. After creating the database . 1. can we change 8kb to 16kb? how can we change?
2. Is there any impact on that database?
Pavan DBA said
hi siva,
1. we cannot change it after creating DB
2. NA
Ravi said
Hi Pavan,
Need small clarification.. I heard like Oracle on Windows/Linux/Solaris platforms.. which one we can choose for a better career perspective..
Pavan DBA said
Hi Ravi, Oracle on Linux or Solaris is good. Very less databases exist on windows when compared to unix flavours
Ravi said
Thanks Pavan. Please let me know if you are providing online training as I’m based out of Bangalore.
Also, can you please clarify my concern : some of my DBA friends suggest me to learn SQL Server & mastering SQL/PL SQL will help me to work better as a successful DBA. Please let me know your point of view.
Thanks again,
Ravi
Pavan DBA said
hi ravi, yes i do provide online training. for more details contact 040-40036087 / 8008500064.
reg another question, sql server is a rdbms like oracle, so learning it will not help to become oracle dba (it helps when u want to be a multi skilled dba)
sql is important, but pl/sql is not. though having pl/sql knowledge will be helpful(but not mandatory)
Ravi said
Hi Pavan,
I’m planning to learn pl/sql parallel to DBA course, though I’m from Non-IT and non program background.
Does learning pl/sql requires good algorithmic skills / logic skills as other programs highly demands (like, sort,stack,arrays . .. etc)
Thanks much in advance for your valuable suggestions.
Thank You,
Ravi
Pavan DBA said
hi ravi, yes it is a programming language like c or java etc
Shadab Nivekar said
Hi Pavan,
I am an Oracle DBA started my career into Oracle as working as a RAC DBA with no prior exp of handling databases oracle databases.
Please answer my below queries :-
1) How much SQL & PLSQL is required for a DBA,
2) To do PT better is SQL & PLSQL is really required,
3) Could you suggest any institute which conducts good training on SQL & PLSQL in Hyderabad,
4) I have chosen my career as a RAC DBA & RAC PT expert,please tell me how should i prepare to become RAC & PT expert.
regards,
Shadab
Pavan DBA said
hi, i believe i have replied u in email. so not replying here
siva said
Hi pavan sir,
i am new to u. i have seen ur complements its so nice. In my pc i have done Dataguard configuration. but archives are not tranfered to standby side what we will do? I have seen alertlogfile of primary but it doesn’t show anything at that time what we will do, to transfer archives from primary to standby?
Could u plz tell for this situation
Pavan DBA said
u need to check alert log file of standby database. also check if MRP process is running. for exact solution, plz post ur db version along with error messages.
uday said
Hi pavan sir,
I have got an interview question recentely from cts which is is in 11gR2 if we do not configure FAL_CLIENT & FAL_SERVER who is going to fill archives gap fill at standby?
I said it is mandatory but he said FAL_CLIENT & FAL_SERVER Is optional in 11gR2 and 12c also for this what we need to tell for this sir? could u plz help me this answer
I am waiting for ur best answer sir………
Drona said
Hi Pavan,
It’s really awesome that you are responding to each and every comment. I would like to know a simple thing.
Could you please tell me if I would like to practice Oracle DBA on my personal computer, what software do I need to install? I mean what applications are required? Thank you in advance.
Pavan DBA said
Hi Drona, first of all thanks for your words. its my reponsibility to respond to all the people.
regarding your question, it depends on which OS you want to practise.
if you are planning to practise on windows, download the softwares mentioned in below link (assuming you are using 64-bit windows)
http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-win64soft-094461.html
after that, you can install it with the help of below document (even though doc is for 10g, same steps you can follow for 11g)
https://pavandba.files.wordpress.com/2009/11/oracle_10g_installation_on_windows_111111.docx
if you want to practise on Linux, then follow below steps
1. download VMware workstation software
http://www.vmware.com
2. download linux software
edelivery.oracle.com
2. download oracle software
http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-linuxsoft-085393.html
for installation of all the above, you can check the videos in my blog
https://pavandba.com/video-tutorials/
Drona said
Thank you so much for the help. I really appreciate for your help. I wish to attend your classes but I am from Noida ;)Thank you again, the links are very helpful.
Pavan kumar said
Hi brother,
I have not done any certifications yet! I am preparing for OCA 11g and searching for latest dumps of OCA 11g, But Oracle keeps changing the questions after every 2 months. So can you please suggest how can I get the latest dumps of OCA 11g
Pavan DBA said
give me ur gmail id.
anilkumar said
Hi Pavan sir,
If sysdba is unable to connect to the database due to some reasons at that time what we will do the sysdba need to connect to the database?
Thanks
Anilkumar
Pavan DBA said
hi anil, it depends on why sysdba was unable to connect. the only scenario I know is when the audit destination is full, then database will not allow sysdba also to connect. in this case u need to go to audit_file_dest location and clear some old audit files. problem will be resolved by that.
if there is any other reason why sysdba is unable to connect, u can check in alert log for the error.
anilkumar said
Thank u for ur good response.
Regards
Anilkumar
anilkumar said
Hi pavan sir, This is anil.
I am getting the following error: ORA-00604:error occurred at recursive sql level 1. This error occurred when I was trying to connect to the database. user. What could be the reason for this and could u tell me the solution for this ORA-604.
ORA-00604: error occurred at recursive SQL level string.
.
Pavan DBA said
plz check alert log for more details. I cannot exactly say the reason with this error.
Naresh said
Hi pavan sir, this is Naresh
When will u take the class for 12cinstallation and brief TOAD. one Week has completed. plz the the class for this 2 topics. we all waiting for ur class. Plz take class as soon as possible. already we informed to Receptionist also. we don’t whether she is convied or not.
Regards
Anilkumar
Pavan DBA said
sorry… I was so busy with the things that I couldn’t complete
Tarun said
Hello,
DB Version 11.2.0.3(Single instance Database) OS version: OEL
When we need downtime?
Thanks in advance
Pavan DBA said
question not clear. plz explain more.
Tarun said
Hello,
This is Tarun. i am new to Oracle database. I have one query regarding alert log file.
Checking alert log file manually for errors is a time consuming process to read the file.
How to see alert log file for errors?
Any help will be highly appreciated.
With Regards
Tarun
Pavan DBA said
if u r using unix flavoured OS, then u can use below command which will give all errors in single shot.
cat alert_sid.log | grep ORA-
if enterprise manager is configured in your env, then u can check in EM db console for only errors in alert log.
Pratheek said
Hi Pavan Garu
This is Pratheek. I am new to Oracle Apps DBA. can you please suggest me which documents are very helpful for me. can you please let me know sir. I mean is there any specific website for that Docs. please suggest me
Thank you
Pavan DBA said
unfortunately i don’t know about apps dba. so can’t help you really.
Pratheek said
K sir not a problem. please tell me on Oracle DBA side. is there any specific documents for understanding the concepts easily.
Pavan DBA said
always it is good to read oracle documentation. it is available here http://www.oracle.com/pls/db112/homepage
Pratheek said
Hi sir
Can you please post how to Install and configure OEM grid control in 10g (or) 11g. if available
Thank you
Pavan DBA said
i will do that in near future. i am busy these days. meanwhile u can check in google for docs
narehs said
Plz tell atleast this answer pavan sir, [ we are ur students ]
what is the difference between MATERIALIZED VIEW & MV LOG? [ if we have any doubt then only we mail you sir ]
Thanks
Naresh
Pavan DBA said
MV is a table to refresh the data in timely fashion from remote database. MV log helps in fast refresh of the data. for more, read this – http://docs.oracle.com/cd/B28359_01/server.111/b28326/repmview.htm
Eswar said
materialized view is stored in data base. query out put stored in data base. if u perform any dml operation on matirialized view we need to refresh other wise dml changes are not effected.
MV log is used for refresh mode Fast . if you want to refresh materialized view with refresh mode “fast” .we need to create materialized view log.this process is called incremental refresh.
Ajeet Kumar said
hi Naresh,
if we perform any dml operation on base table, it is not visible to the mv (materialized view) until we perform refresh operation. In normal refresh(complete refresh or default referesh) opertion new replica of data is stored as mv and older mv is destroyed. It is not effiecient as each time we execute refresh new mv data is created, thats y we use fast refresh. here in fast referesh if we execute any dml statement on base table then oracle db stores that changes in mv view log, and latter that log is used for refresh mv table based on base table. If we dnt have MV log then we need to reexecute the mv query to refresh mv, which will become complete refresh or default refresh…
Ajeet
naresh said
Hi pavan sir,
What is the difference between SYS USER & SYSTEM USER? And what privileges will have SYS & SYSTEM ?could u plz explain indetails sir.
Pavan DBA said
check in oracle documentation @ Tahiti.oracle.com
Naresh said
BATCH NO : 37
1. If I am having 2 oracle versions like Oracle 10g and 11g. Then can I mention/set both the ORACLE_HOME path and ORACLE_SID name in the bash_profile? how it will work?
2. There are 2 types of inventories which are LOCAL INVENTORY & GLOBAL INVENTORY what information contains local inventory & global inventory?
Could u plz explain me
Pavan DBA said
1. you can define only one. but you can use some shell script in order to specify both versions. u can get shell script from google.
2. global inventory holds all product information. local inventory will store only one oracle_home information.
see this http://www.appsdbatraining.com/2011/11/22/diff-local-inventory-global-inventory/
nagesh said
Dear Pavan,
I need some information for Oracle database restore point,I am planing to release some critical objects in Oracle 11g database and before we have to set oracle restore point for flashback.Could please provide the information and how to use restore point if face any issues in activity.
Thanks in advance,
Best regards,
Nagesh.
.
Pavan DBA said
see this – http://docs.oracle.com/cd/B19306_01/backup.102/b14192/rpfbdb002.htm
Simli said
Hello Pavan sir,
I am a newbie to oracle. I have gone through the oracle 11g documentation. I am having few queries regarding Oracle software(11.2.02) installation on RHEL5.
1. What are the things that one should check after the installation of an Oracle software?
2.How to verify root.sh ran or not?
Any help will be highly appreciated.
Thanks and regards
Simli
Pavan DBA said
1. if u can able to create database and if its working fine, then u dnt require any other checks
2. if root.sh is ran properly, then it will create oratab file in /etc location. chk if that file is there or not
Simli said
Thanks pavan sir
Rama said
Hi Pavan,
i m rama working as Jr oracle dba in Product based company(Bangalore). I know only core dba part. Now i planning to learn ASM,Dataguard,RAC..etc. So is there any fast track course.
Thanks in advance,
Rama
Pavan DBA said
Hi Rama, ASM, dataguard, cloning, upgrade etc topics are included in the DBA course itself where as RAC is a separate course.
we don’t have any fast track batches for DBA, but if possible u can attend online batch. timings are 8:30 to 10 PM. Already a batch started last week and we are in installation phase.
If you wish to attend only adv topics, you may need to wait for another 10-15 days.
To know about RAC batch details, plz call to 040-40036087 / 8008500064
vinay said
sir ,RAC 11g 2 and PT ,dataguard fee sturcture online
do u have material i can learn from home
Pavan DBA said
hi vinay, u can read oracle documentation for the same. also there are so many e-books available for download.
Shuv said
Hello,
Why I have to put a “.”(dot) when executing oraenv?
Pavan DBA said
. represents tht u r executing a command (oraenv is a command)
Binu said
Hello,
I am having few queries regarding oracle inventory.
1)I am maintaining multiple oracle homes within a single server for different oracle versions(10.2.0.4,11.2.0.2 & 11.2.0.3). There is one Global inventory for all oracle homes. For some reason, the global inventory gets corrupted. Oracle provides us with a method to recreate the global inventory by using “oui –attachhome” option. My question is in order to update the inventory about the physical location of multiple oracle homes, do I need to run this command from every $ORACLE_HOME or a single oracle home will do?
2) Global Inventory could be placed anywhere which can be determined from inventory_loc in oraInst.loc.Can we change the location of local inventory or does local inventory always reside inside $ORACLE_HOME?
Thanks and Regards
Pavan DBA said
1. yes from every oracle home
2. it should be out of oracle_home. usually we place in the location which points in oraInst.loc. if u place in any other location, then u need to change the path in oraInst.loc file
Binu said
Thanks for your reply.
oraInst.loc file points to the the location of the global inventory ($ORACLE_BASE/oraInventory). We can change this location by configuring oraInst.loc file. Can we change the location of Local inventory($ORACLE_HOME/inventory)?
Thanks and regards
Pavan DBA said
yes u can. what ever location u feel correct, u can update it in that file
Ankita said
Hello,
How listener will decide to start a dedicated server process or to handover dispatcher? DB Version 11.2.0.3 and OS version RHEL5
Any help will be highly appreciated.
Regards
Ankita
Pavan DBA said
Hi Ankita,
this we will be mentioning in tns entry. for example when look at below two tns entries (bold letters), first one is specified with dedicated connection (which is default) and second entry specifies shared connection
net_service_name=
(DESCRIPTION=
(ADDRESS=…)
(ADDRESS=…)
(CONNECT_DATA=
(SERVER_NAME=sales.us.example.com)
(SERVER=dedicated)))
net_service_name=
(DESCRIPTION=
(ADDRESS=…)
(ADDRESS=…)
(CONNECT_DATA=
(SERVER_NAME=sales.us.example.com)
(SERVER=shared)))
Ankita said
Thanks pavan for your reply.
1)It means Whether a connection gets a shared or a dedicated is determined by the client side. Am i correct in my understanding?
2)If shared servers are configured, by default all connections will be entertained by shared server. In that case we still need (SERVER=shared) in tnsnames.ora file?
Thanks
Pavan DBA said
1. yes
2. if we configure shared server at DB level, the connections will not use that directly until we specify this in tnsnames.ora file
Pinaki said
I assigned two IP’s to ethernet (eth0 & eth1), entered them in /etc/hosts with following entry:
172.16.180.43 prodhost.prodomain prodhost
172.16.180.44 prodhost.prodomain prodhost
The listener PROD_LIST is defined in listener.ora using hostname
PROD_LIST =
(ADDRESS_LIST =
(ADDRESS= (PROTOCOL= TCP)(Host= prodhost)(Port= 1522))
)
My question is Will the listener listen only on 172.16.180.43 or on both 172.16.180.43 and 172.16.180.44?
Pinaki
Pavan DBA said
even though i have never tested this before, but having knowledge of similar background on RAC, i say usually it will listen to eth0 network adapter i.e 172.16.180.43
raj said
Can you explain Golden Gate in Oracle DBA
Pavan DBA said
you can go thru below links
http://gssdba.wordpress.com/category/oracle-golden-gate/
http://www.oracle.com/technetwork/middleware/goldengate/documentation/index.html
subhashini said
hiiiiii pavan this is urs subhashini teacher (english) how r u ???
wrkd in lions school 1twn vij
Pavan DBA said
Hi Madam, its really great to meet you like this. got a surprise that you commented on my blog. I am doing fine teacher and hope you are also doing good. I am so so happy… will mail you personally.
Namrata said
Hello Pavan sir,
I am new to the Oracle world. I’m new at administrating a database (11.2.0.2 on RHEL5). I am having few queries regarding Listener. My questions are as follows:
1)Is there any difference between setting “host=” and “host=” in listener.ora file?
2) Which one is recommended to use host= or host=?
I hope you answer me.
Thanks and regards
Pavan DBA said
sorry, I didn’t got ur question? it seems both are same (host= and host=). plz explain clearly
Ankita said
Hello,
What benefits are their using ASM over file system?
Any help will be highly appreciated.
Regards
Ankita
Pavan DBA said
simple to say asm uses raw devices instead of formatted disks. this will improve performance. more u can read from google
https://www.google.co.in/search?q=benefits+of+using+asm&aq=f&oq=benefits+of+using+asm&aqs=chrome.0.57j60j0.4544j0&sourceid=chrome&ie=UTF-8
Binu said
Hello,
I am having few queries regarding Patching.
1) What is the drawback if we don’t upgrade to latest patchset (i.e. from 11.2.0.1 to 11.2.0.2 or 11.2.0.3)?
2) Difference between Database Upgrade and Patchset Upgrade?
Thanks and Regards
Pavan DBA said
1. there is no drawback. basically applying patchset is to avoid any bugs hitting your database
2. patchset upgrade involves database upgrade as version of the software changes.
Eswar said
Hi Pavan,
I have doubt on carrer prospective.
I am looking for abroad opertunities.
I have experince in oralce developer(2 yrs).
i want to change the plat form like oralce apps technical
or oralce dba. whcih course is having more opertunities in abroad.
Thanks in advance for giving reply.
thnaks,
Eswar
Pavan DBA said
Oracle DBA is having very good market in aboard, but I am not sure about oracle apps technical.
Eswar said
ok pavan.i am pl/sql developer.how can i move to oracle dba in s/w.
is there any chances to built in carrer in dba side for me ?
Pavan DBA said
you need to learn oracle dba course and once done you can ask for technology change in your current company
Binu said
Hello
Hope you are doing fine.I have a couple of questions regarding Standby DB.
1) Why is supplemental logging needed in Oracle Logical Standby DB?
2) What is the exact relationship between LGWR and LNS?
Thanks and regards
Pavan DBA said
1. Supplemental logging must be enabled on the primary database to support a logical standby database. Because an Oracle Database only logs the columns that were modified, this is not always sufficient to uniquely identify the row that changed and additional (supplemental) information must be put into the stream of redo data. The supplemental information that is added to the redo data helps SQL Apply to correctly identify and maintain tables in the logical standby database.
2. read this – http://www.datadisk.co.uk/html_docs/oracle_dg/architecture.htm
Dinesh yadav said
Dear Pavan,
We are looking for a Oracle DBA cum developer. Who is interested to work at Tanzania and having some exposure in training. Kindly let me know in case you have any friend / known in your knowledge.
Thanks & Regards,
Pavan DBA said
Hi Dinesh, can you let me know what level of developer work would be there?
Pavan Gurram said
Dear Dinesh,
I have worked as Oracle DBA cum Developer and having relevant experience. Pl let me know can I have any chance
Somnath said
Hello Pavan,
I am very new to Data guard technology. I have few questions regarding Physical Standby DB.
1)Do I need to left blank LOG_ARCHIVE_DEST_2 parameter on Standby Database init parameter?
2) What impact does NOARCHIVELOG mode have on standby database?
3) If the standby archive destination is full, what will happen? Will the standby DB freeze? or will oracle stop redo transport from primary to standby?
With regards
Pavan DBA said
1. You can leave that as blank, but if you do that, you cannot do switchover between primary and standby databases.
2. you can have standby in NO ARCHIVELOG MODE, but again as i said above, during switchover it will create problem.
3. yes. standby DB will freeze and even primary will stop redo transport also.
Binu said
Hello
1) What will happen if the size of the current standby Redo log on standby database doesn’t match the size of the online Redo Log file on the Primary database?
2)How can I open the standby in read only mode if I have no online redo logs?
Pavan DBA said
1. there will be no impact except on the performance. that too we can’t say until experience it. usually we expect standby to be replica of primary and that is why it is recommended to maintain same config even at hardware level.
2. still you can open it in read only because online redologs are needed only for write purpose.
Meraj Ahmed said
Hello Sir
Presently i’m doing B.com ( frst year) , I m very interested in computers fields.
my teachers even say DBA is a very good option .
sir im i eligible to go for a DBA training?
how can i start off? please help me
Pavan DBA said
Hi Meraj, yes you will be eligible for DBA course. Please take training from any good institute on Oracle 11g DBA course. But as you are in first year only, i suggest you can do this in your last year of graduation
reza said
Suppose we need to run the following:
run {
set until scn ;
duplicate target database to clone nofilenamecheck;
}
In order to get the SCN, can we use “list backup of archivelog all” and “list backup” or anything else?
Pavan DBA said
yes. u can use list backup.
Somnath said
Can you tell me the difference between duplicating a database and restoring a database
With regards
Pavan DBA said
even though both do the same action (clone a database), the method used is different. in duplicating, we use rman’s duplicate database command to do that, where as in restoring database, we do complete database recovery including spfile. moreover, in duplicate u can use any name for auxiliary database, but when using restore database u need to use same name
kondareddy.G said
Hi..sir please help to me because i know sql/plsql ,but i don’t know oracle-dba and db2 and remaiming concepts ..please suggestion to me .
i will start preparation ,please guidance for which concepts are first startl like (steps wise which one first first start)…
please..please ..sir help to me
Pavan DBA said
i have already listed the books in my blog. plz go through them n you will get knowledge on oracle dba
Binu said
Hello,
I have 2 questions regarding RMAN Cloning.
1)When RMAN duplicates the database does it create the tablespace sizes exactly the same or create what is actually being used in the tablespace?
2)Why does everyone use RMAN DUPLICATE as the preferred method to create a duplicate database?
Thanks and regards
Pavan DBA said
1. it will create the same size as in target database.
2. as RMAN duplication is easier when compared to cold or hot backup cloning, it is preferred. also, less human effort exist in that
Binu said
Thanks
Sravankumar Reddy said
hi sir is there any vacancies for freshers dba can u inform me kalyan.r123@gmail.com
Pavan DBA said
u can check in my blog itself. or u can register with ur email id so that u will get alerts from my blog
shaik munaf said
Hello,
This is munaf. Am new to RAC environment. When I configured pre-requisites for oracle 10g rac and run clufvy i got the below error .
[oracle@rac1 cluvfy]$ ./runcluvfy.sh stage -pre crsinst -n rac1,rac2 -verbose
Performing pre-checks for cluster services setup
Checking node reachability…
Check: Node reachability from node “rac1”
Destination Node Reachable?
———————————— ————————
rac2 yes
rac1 yes
Result: Node reachability check passed from node “rac1”.
Checking user equivalence…
Check: User equivalence for user “oracle”
Node Name Comment
———————————— ————————
rac2 passed
rac1 passed
Result: User equivalence check passed for user “oracle”.
Checking administrative privileges…
Check: Existence of user “oracle”
Node Name User Exists Comment
———— ———————— ————————
rac2 yes passed
rac1 yes passed
Result: User existence check passed for “oracle”.
Check: Existence of group “oinstall”
Node Name Status Group ID
———— ———————— ————————
rac2 exists 5001
rac1 exists 5001
Result: Group existence check passed for “oinstall”.
Check: Membership of user “oracle” in group “oinstall” [as Primary]
Node Name User Exists Group Exists User in Group Primary Comment
—————- ———— ———— ———— ———— ————
rac2 yes yes yes yes passed
rac1 yes yes yes yes passed
Result: Membership check for user “oracle” in group “oinstall” [as Primary] passed.
Administrative privileges check passed.
Checking node connectivity…
Interface information for node “rac2”
Interface Name IP Address Subnet
—————————— —————————— —————-
eth0 192.168.128.123 192.168.128.0
eth1 192.168.129.123 192.168.129.0
Interface information for node “rac1”
Interface Name IP Address Subnet
—————————— —————————— —————-
eth0 192.168.128.122 192.168.128.0
eth1 192.168.129.122 192.168.129.0
Check: Node connectivity of subnet “192.168.128.0”
Source Destination Connected?
—————————— —————————— —————-
rac2:eth0 rac1:eth0 yes
Result: Node connectivity check passed for subnet “192.168.128.0” with node(s) rac2,rac1.
Check: Node connectivity of subnet “192.168.129.0”
Source Destination Connected?
—————————— —————————— —————-
rac2:eth1 rac1:eth1 yes
Result: Node connectivity check passed for subnet “192.168.129.0” with node(s) rac2,rac1.
Suitable interfaces for the private interconnect on subnet “192.168.128.0”:
rac2 eth0:192.168.128.123
rac1 eth0:192.168.128.122
Suitable interfaces for the private interconnect on subnet “192.168.129.0”:
rac2 eth1:192.168.129.123
rac1 eth1:192.168.129.122
ERROR:
Could not find a suitable set of interfaces for VIPs.
Result: Node connectivity check failed.
Checking system requirements for ‘crs’…
Check: Total memory
Node Name Available Required Comment
———— ———————— ———————— ———-
rac2 1010.29MB (1034536KB) 512MB (524288KB) passed
rac1 748.36MB (766324KB) 512MB (524288KB) passed
Result: Total memory check passed.
Check: Free disk space in “/tmp” dir
Node Name Available Required Comment
———— ———————— ———————— ———-
rac2 9.4GB (9852104KB) 400MB (409600KB) passed
rac1 8.88GB (9310020KB) 400MB (409600KB) passed
Result: Free disk space check passed.
Check: Swap space
Node Name Available Required Comment
———— ———————— ———————— ———-
rac2 1.94GB (2031608KB) 1GB (1048576KB) passed
rac1 1.47GB (1540088KB) 1GB (1048576KB) passed
Result: Swap space check passed.
Check: System architecture
Node Name Available Required Comment
———— ———————— ———————— ———-
rac2 i686 i686 passed
rac1 i686 i686 passed
Result: System architecture check passed.
Check: Kernel version
Node Name Available Required Comment
———— ———————— ———————— ———-
rac2 2.6.9-89.ELsmp 2.4.21-15EL passed
rac1 2.6.9-89.ELsmp 2.4.21-15EL passed
Result: Kernel version check passed.
Check: Package existence for “make-3.79”
Node Name Status Comment
—————————— —————————— —————-
rac2 make-3.80-7.EL4 passed
rac1 make-3.80-7.EL4 passed
Result: Package existence check passed for “make-3.79”.
Check: Package existence for “binutils-2.14”
Node Name Status Comment
—————————— —————————— —————-
rac2 binutils-2.15.92.0.2-25 passed
rac1 binutils-2.15.92.0.2-25 passed
Result: Package existence check passed for “binutils-2.14”.
Check: Package existence for “gcc-3.2”
Node Name Status Comment
—————————— —————————— —————-
rac2 gcc-3.4.6-11 passed
rac1 gcc-3.4.6-11 passed
Result: Package existence check passed for “gcc-3.2”.
Check: Package existence for “glibc-2.3.2-95.27”
Node Name Status Comment
—————————— —————————— —————-
rac2 glibc-2.3.4-2.43 passed
rac1 glibc-2.3.4-2.43 passed
Result: Package existence check passed for “glibc-2.3.2-95.27”.
Check: Package existence for “compat-db-4.0.14-5”
Node Name Status Comment
—————————— —————————— —————-
rac2 compat-db-4.1.25-9 passed
rac1 compat-db-4.1.25-9 passed
Result: Package existence check passed for “compat-db-4.0.14-5”.
Check: Package existence for “compat-gcc-7.3-2.96.128”
Node Name Status Comment
—————————— —————————— —————-
rac2 compat-gcc-7.3-2.96.128 passed
rac1 compat-gcc-7.3-2.96.128 passed
Result: Package existence check passed for “compat-gcc-7.3-2.96.128”.
Check: Package existence for “compat-gcc-c++-7.3-2.96.128”
Node Name Status Comment
—————————— —————————— —————-
rac2 compat-gcc-c++-7.3-2.96.128 passed
rac1 compat-gcc-c++-7.3-2.96.128 passed
Result: Package existence check passed for “compat-gcc-c++-7.3-2.96.128”.
Check: Package existence for “compat-libstdc++-7.3-2.96.128”
Node Name Status Comment
—————————— —————————— —————-
rac2 compat-libstdc++-7.3-2.96.128 passed
rac1 compat-libstdc++-7.3-2.96.128 passed
Result: Package existence check passed for “compat-libstdc++-7.3-2.96.128”.
Check: Package existence for “compat-libstdc++-devel-7.3-2.96.128”
Node Name Status Comment
—————————— —————————— —————-
rac2 compat-libstdc++-devel-7.3-2.96.128 passed
rac1 compat-libstdc++-devel-7.3-2.96.128 passed
Result: Package existence check passed for “compat-libstdc++-devel-7.3-2.96.128”.
Check: Package existence for “openmotif-2.2.3”
Node Name Status Comment
—————————— —————————— —————-
rac2 openmotif-2.2.3-10.5.el4 passed
rac1 openmotif-2.2.3-10.5.el4 passed
Result: Package existence check passed for “openmotif-2.2.3”.
Check: Package existence for “setarch-1.3-1”
Node Name Status Comment
—————————— —————————— —————-
rac2 setarch-1.6-1 passed
rac1 setarch-1.6-1 passed
Result: Package existence check passed for “setarch-1.3-1”.
Check: Group existence for “dba”
Node Name Status Comment
———— ———————— ————————
rac2 exists passed
rac1 exists passed
Result: Group existence check passed for “dba”.
Check: Group existence for “oinstall”
Node Name Status Comment
———— ———————— ————————
rac2 exists passed
rac1 exists passed
Result: Group existence check passed for “oinstall”.
Check: User existence for “nobody”
Node Name Status Comment
———— ———————— ————————
rac2 exists passed
rac1 exists passed
Result: User existence check passed for “nobody”.
System requirement passed for ‘crs’
Pre-check for cluster services setup was unsuccessful on all the nodes.
When i google it i got some suggestions that just ignore vip for instance and continue installation.
when i installed cluster i stuck on the last cofiguration post installation steps:
Checking existence of VIP node application (required)
Check failed.
Check failed on nodes:
rac2,rac1
Checking existence of ONS node application (optional)
Check ignored.
Checking existence of GSD node application (optional)
Check ignored.
Post-check for cluster services setup was unsuccessful on all the nodes.
Configuration assistant “Oracle Cluster Verification Utility” failed
—————————————————————————–
The “/u01/home/oracle/product/10.2.0/crs/cfgtoollogs/configToolFailedCommands” script contains all commands that failed, were skipped or were cancelled. This file may be used to run these configuration assistants outside of OUI. Note that you may have to update this script with passwords (if any) before executing the same.—————————————————————————–Output generated from configuration assistant “Oracle Cluster Verification Utility”:
Command = /u01/home/oracle/product/10.2.0/crs/bin/cluvfy stage -post crsinst -n rac1,rac2
User equivalence check passed for user “oracle”.
Checking Cluster manager integrity…
Checking CSS daemon…
Daemon status check failed for “CSS daemon”.
Check failed on nodes:
rac2
Cluster manager integrity check failed.
Checking cluster integrity…
Cluster integrity check failed. This check did not run on the following nodes(s):
rac2
Checking OCR integrity…
Checking the absence of a non-clustered configuration…
All nodes free of non-clustered, local-only configurations.
ERROR:
Unable to obtain OCR integrity details from any of the nodes.
OCR integrity check failed.
Checking CRS integrity…
Checking daemon liveness…
Liveness check failed for “CRS daemon”.
Check failed on nodes:
rac2
Checking daemon liveness…
Liveness check failed for “CSS daemon”.
Check failed on nodes:
rac2
Checking daemon liveness…
Liveness check failed for “EVM daemon”.
Check failed on nodes:
rac2
Checking CRS health…
CRS health check passed.
CRS integrity check failed.
Checking node application existence…
Checking existence of VIP node application (required)
Check failed.
Check failed on nodes:
rac2,rac1
Checking existence of ONS node application (optional)
Check ignored.
Checking existence of GSD node application (optional)
Check ignored.
Post-check for cluster services setup was unsuccessful on all the nodes.
Configuration assistant “Oracle Cluster Verification Utility” failed
—————————————————————————–
The “/u01/home/oracle/product/10.2.0/crs/cfgtoollogs/configToolFailedCommands” script contains all commands that failed, were skipped or were cancelled. This file may be used to run these configuration assistants outside of OUI. Note that you may have to update this script with passwords (if any) before executing the same.—————————————————————————–
plz help me.
Pavan DBA said
can u let me know which document u r following?
shaik munaf said
oracle-base
http://www.oracle-base.com/articles/10g/oracle-db-10gr2-rac-installation-on-centos-4-using-vmware.php
solo said
I found good points from your blog
Pavan DBA said
thank you
Binu said
Hello,
I have one query regarding Cloning.
There is a new Linux(RHEL5) box and I am planning to clone an Oracle production database(10g on RHEL5) to new Linux(RHEL5) box for testing upgrades, testing pacthes before applying the same on the production database. My question is do I need to match the cloned system environment include hardware, memory & disc allocation space with the production system environment?
Thanks and regards
Pavan DBA said
yes. it would be better if it matches with hardware. if not atleast it should match the space requirement as of prod
Binu said
Thanks for your valuable reply
oracle said
Hi Sir,
I am working as an Oracle DBA But not getting much more exposure so i have a limited knowledge. So can u guide me what should i have to do ?
Thanks
Pavan DBA said
Hi, i suggest to read oracle documentation and books available online and do a self learning in practicals also. i have already given the list of books in my blog. go through them
sorry culdn’t reply u bcz i am on leave since 3 weeks
Ramjan Ali said
I want become a oracle dba….what i should do?
Pavan DBA said
u need to have knowledge on sql and learn unix basics. after that you need to do oracle dba course from any institute which will make you good in oracle dba
sorry culdn’t reply u bcz i am on leave since 3 weeks
Binu said
Hello,
Is there any difference between granting a privilege directly by GRANT command and through a ROLE?
Thanks and regards
Binu
Pavan DBA said
there will be no difference. only reason is role will help us to grant that privilege to so many users.
sorry culdn’t reply u bcz i am on leave since 3 weeks
Binu said
Thanks for your reply
Anand Hebsur said
Hi Pavan,
This is Anand hebsur from karnataka, Presently working as an System admin cum ERP Admin at Dammam (KSA). We are having Oracle 10g database in windows platform. Some things i know in DBA but that much not in detail.
I want to make my career as an DBA. Please guide me and let me know which institute i have to join and whether they will be providing placement or not ?
Pavan DBA said
Hi Anand,
I am providing online training. If you are interested, you can join next batch which might start in 2nd week of feb.
for dates and other details, keep watching new batches section in my blog http://www.pavandba.com
sorry culdn’t reply u bcz i am on leave since 3 weeks
binu said
Hello
Hope you are doing fine.I have a couple of questions regarding ASM SPFILE. ASM Version 10R2
1)How ASM instance can read the SPFILE from ASM disks, id they are not mounted?
2) How ASM knows where to get SPFILE if there is no init.ora file in $ORACLE_HOME/dbs with SPFILE=[path to spfile]
parameter?
Thanks and Regards,
Binu
Pavan DBA said
this link helps you – http://blog.trivadis.com/b/robertbialek/archive/2012/07/04/oracle-asm-spfile-stored-in-an-asm-disk-group-how-it-works.aspx
venkat said
Hi Pavan,
I am searching for a job in oracle DBA, I learn Oracle DBA 1 year back still i am not getting any job, right now i am planning to learn Apps DBA Pls. give any suggestions
Actually i never practice DBA from the last six months almost i forgot the concepts so directly i can go for Apps or not
how much core DBA knowledge is required to learn Apps DBA.
Pavan DBA said
you need practise on high end topics like cloning, upgrade, patching etc in order to learn apps dba. so plz get hands on for those topics
Harsh said
Hi Pavan,
I need your guidance in my career path.I’m working as an Oracle DBA but most of my job part is Oracle Performance Tuning and nothing related to cloning,patching and RMAN etc..as there are different teams for these activities.But when I search any job online they asked for all these activities as part of DBA job.So how could I get a job as an Oracle Performance DBA.Please guide me into this.Please let me know ur email-id so that I can share my resume with you,help me into this.
Thanks
Harsh
Pavan DBA said
most of the companies will not have separate teams to work as tuning specialist etc. so i feel it is better you can refresh your knowledge on those areas like cloning, patching etc. as you are already working as DBA and know about oracle, it will not take much time
anusha said
hii sir ,
I am a regular follower of ur blog ..firstly thanks a lot for ur useful inforamation.I completed my oracle dba , and i m searching for ORACLE APPS institiutes at hyderabad ..i have seen lot of institutes , and i am not satisfied with faculty .. pls , suggest me a good institute ..
thanks
anusha.
Pavan DBA said
hi anusha, i am not sure exactly. i heard sri sai technologies, wilshire are good. have you tried kanna technologies also?
poorna said
Hi sir, this is purna i just completed oracle dba, mca pass out 2012 i want guidence and advices in subject.
Pavan DBA said
hi purna, let me know how can i help you?
poorna said
hi sir gud mrg, is there any requirements for freshers on oracle dba. if u dont mine can u send sample resumes for fresher dba..
Pavan DBA said
any requirements, i will post in my blog itself
Lakshman said
Hi Pavan
I am an Experienced IT professional like to change my career to Oracle DBA line.I have done my Oracle Certification long back and I am an OCA but couldnt get a breakthru into oracle dba line .It will be great if you can advice or give your thoughts .
Thanks
Lakshman
Pavan DBA said
usually i suggest to try in your company for a role change. if not you need to look for another opp stating you want to change your technology (ofcourse valid reason should be there to project in interviews)
Lakshman said
Pavan
Thanks for the reply.Its a good suggestion,since I am in a Lead position when I am trying to switch either in my company or other companies they are unable to accept me for Oracle DBA entry /Junior level position because of Grade /Level issues even though I am open for negotiations.
Your thoughts on this please.
Thanks
Pavan DBA said
i hope if you can prove that you have knowledge of an exp’d dba, then i think some companies will give a chance
murali said
Hi Pavan sir,
This is Murali from hyderabad… i have recently completed my Oracle DBA course, and searching for a job, unfortunately there are no openings for Freshers,my graduation 2010 my qlf mca.but i have doubt fresher jobs is thir or not in dba field .what would you suggest?
Pavan DBA said
hi murali, yes fresher dba jobs are very less. along with dba if u learn oracle rac and apps dba, then chances would be more. plz send me mail to mymailbox.21@gmail.com, so that i can discuss more
shaikhkzeeshan1989 said
Im taking table level export as non sys user from one database, however table structure don’t exist where i will import the table, will it get create automatically or it will thrown an error?
Pavan DBA said
it will be created automatically
parijeetc said
Hi Pavan,
This is Parijeet from Pune… i have recently completed my Oracle DBA course, and searching for a job, unfortunately there are no openings for Freshers, so I was thinking of learning something more about database or learn something which will help me getting a job as a developer ( related to database).. i am a fresher and dont have any technical background.. what would you suggest?
Pavan DBA said
Hi Parijeet, i would suggest you to do Oracle RAC and Oracle APPS DBA courses too. This will improve the chance of getting job as a fresher. Also, OCP certification will help you alot.
BTW, what is your qualfn and yr of passout?
parijeetc said
Hi Pavan Sir,
Thank you so much for your reply, i have done MBA(Finance) in 2007 and and dont have any technical background currently working with Mphasis (Pune) for international BPO.
When i spoke to Mr Randy Overmyer (Director of IT at ABVI-Goodwill-US) he said :- Oracle’s new customer DB license sales have been fairly flat for 5 years – it’s crazy to try to enter that job market on an entry level. If you paid for an Oracle course out of your own pocket you’ve probably dumped enough money down the drain, You should spend money on moving into more mainstream products such as The largest DB product is MS SQL, then look at the open source DB products – they get more of the start-up market.
was he right? please guide me?
I was thinking of joining Saturn infotch(Pune) / Blink consulting(Pune) for their training cum job program for Oracle application technical consultant, is it a good option?? Please guide me about this position? As I would be investing 1.25 lacs for this course.
Kindly suggest
Pavan DBA said
Always there will be a competition between different database vendors and I cannot comment on which will have good market and which doesn’t. But i can surely say Oracle will have its share in the market….
coming to course wise, i am not sure about the genunity of those training consultancies, but i feel 1.25 lac is too much costly for oracle course. Personally i don’t suggest to join those kind of places
chandu said
Hi Sir,
When I install Oracle 10g i am getting below errors,Could you please provide the solution.
S/W:Oracle10g
Platform:Linux 4 64-bit
===========================================================================
./runInstaller
Starting Oracle Universal Installer…
Checking installer requirements…
Checking operating system version: must be redhat-3, SuSE-9, SuSE-10, redhat-4, redhat-5, UnitedLinux-1.0, asianux-1, asianux-2 or asianux-3
Passed
All installer requirements met.
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2009-06-09_11-54-16AM. Please wait …[oracle@findb1 Disk1]$ Oracle Universal Installer, Version 10.2.0.4.0 Production
Copyright (C) 1999, 2008, Oracle. All rights reserved.
Can’t connect to X11 window server using ‘10.76.101.161’ as the value of the DISPLAY variable.
10.76.101.161
10.76.101.161
OUI-10025:Unable to start an interactive install session because of the following error:Can’t connect to X11 window server using ‘10.76.101.161’ as the value of the DISPLAY variable. The DISPLAY environment variable should be set to :, where the is usually ‘0.0’.
OUI-10026epending on the Unix Shell, you can use one of the following commands as examples to set the DISPLAY environment variable:
– For csh: % setenv DISPLAY 192.168.1.128:0.0
– For sh, ksh and bash: $ DISPLAY=192.168.1.128:0.0; export DISPLAY
Use the following command to see what shell is being used:
echo $SHELL
Use the following command to view the current DISPLAY environment variable setting:
echo $DISPLAY
– Make sure that client users are authorized to connect to the X Server.
OUI-10027:To enable client users to access the X Server, open an xterm, dtterm or xconsole as the user that started the session and type the following command:
% xhost +
To test that the DISPLAY environment variable is set correctly, run a X11 based program that comes with the native operating system such as ‘xclock’:
%
If you are not able to run xclock successfully, please refer to your PC-X Server or OS vendor for further assistance.
Typical path for ‘xclock’: ‘/usr/X11R6/bin/xclock’
Pavan DBA said
you must set DISPLAY variable for starting runInstaller. there is info on how to set it after the error. please check that
Rahul said
I would like to ask you few questions regarding oinstall and dba group.
1) Is there any difference betwwen oinstall & dba group?
2) What is oinstall group?
Pavan DBA said
There is installation doc in my blog’s “important docs” page. That doc is having those details
Binu said
Thanks for your reply. I have one more query regarding Catalog and Catproc.
Is there any order in which the catalog.sql and catproc.sql scripts to be run?
Pavan DBA said
there is no order in specific. but we run catalog.sql first and then catproc.sql
Binu said
Hello,
Hope you are doing fine. I have two questions regarding Catalog.sql and catproc.sql
1)What will happen if catalog and cataprog not run as SYS user?
2) Catalog.sql creates data dictionary views, dynamic performance views. Can Oracle function properly without these views? (Suppose catalog.sql not run after DB creation)
Thanks and regards
Binu
Pavan DBA said
1. the ownership of the views getting created will change. apart from that i don’t think any other impact (ofcourse i never tested this)
2. yes. oracle still work fine without these views. those are only for DBA’s reference
Ganapthi said
hai sir
in my one of rac database timsmims which is in asm mode, while i changed one parameter it could not start at next restart i would like to start
from pfile each instance it up, after i created spfile from pfile , i shutdown each instance at sql again i issue startup commond, but it unable to start and i did not find any errors or changes in alert log file
please guide me what was problem that database not starting with spfile.
Pavan DBA said
normally when you have asm in place, oracle will create spfile in ASM disk. You need to give that location in your pfile and then you need to start your instance.
open your pfile and write below line
spfile=’location and file name where spfile resides’
save the pfile and then start your instance. this may work
chinmoy said
Dear Sir,
I want to import full database from a exported datapump file in
another machine.both the servers are running in widows,oracle version is 10gR2 . please send me the step-by-step procedure.
Chinmoy
Kolkata,India
Pavan DBA said
1. first you need to copy the dumpfile to target server
2. run the below command
imp file=”ur dumpfile name” log=”import log name” full=y
it will ask for username and password. give “/ as sysdba”, it will do import
Vishnuvardhan Reddy said
Hi Pvan,
Can we have multiple ASM instances on a single server?
Thanks,
Vishnuvardhan Reddy Pandiri
Pavan DBA said
yes we can have
Ahmed said
Hi Pavan,
Just wanted to ask you how many days of archives do we need to keep.
We take cold backup everyday.
Thanks
Ahmed
Pavan DBA said
if you are taking cold backup, then there is no necessity to store archives. after the cold backup, you can delete all previous archives.
Ahmed said
Thanks for your reply…
You are really awesome and helpful.
Thanks
Ahmed
Pavan DBA said
thanks for your kind words
Binu said
1) When to use 10046 Trace?
2) What is the purpose of the “Row Source operation” section in TKPROF report?
Thanks and Regards,
Binu
Pavan DBA said
10046 is nicely explained here – http://www.oracle-base.com/articles/10g/sql-trace-10046-trcsess-and-tkprof-10g.php
chandu said
Pavan gi could you please provide grid software and installation document on linux os.
Pavan DBA said
here is the link for installation guide – http://docs.oracle.com/cd/E11882_01/install.112/e22489/toc.htm
link from where you can download s/w – http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-linuxsoft-085393.html
chandu said
Sir i got one error while creating the 11g database using dbca on solaries env,Error as”ORA-12560:TNS:Protocol adapter error”
Pls help us,little bit urgrent.
Pavan DBA said
please check the log file of dbca to understand more about the error
sau said
Hi Pavan,
Hope you are in good health. Today i have few queries regarding Standby Redo Logs.
1) We need standby redo log on Primary database for switchover.Right? How many
Standby Redo Log group will be required on the Primary?
2) The size of the current standby redo log files must exactly match the size of the
current primary database online redo log files.What is the exact reason behind
this?
3) Standby Redo Logs require multiplexing?
With Regards
Sau
Pavan DBA said
1. We need to have same no.of redo log groups as primary. Some DBA’s will follow n+1 formula i.e if primary is having 3 groups, they will create 4 standby groups. but even 3 is also sufficient
2. yes it should match, because standby is replication of primary
3. Yes it require. because after switchover or failover, standby will be primary
Sree said
1. Oracle recommends to have n+1 groups
2. Should be equal or more in size
3. Need not.
Regards,
Sree
Pavan DBA said
Hi Sree, can you post complete question?
Anurag Kumar Pandey said
sir currently working as software engineer to develope web-application since 1 year using open-source technology(php,postgres-sql,mysql)
but i am very much interested in dba since 2008 so sir what the right step to go for dba job ,sir i am very confuse first i join oracle developer Or Oracle dba i am lot of confuse what to do ?
please sir tell me and guide me about right direction to career.
about education–
1 – B.tech. in computer science & engineering 2010 with 73%
2- Diploma in Electronics Engineering 2007 with 76%
my email-id anuragkumarjoy@gmail.com
Pavan DBA said
You can join Oracle dba. Don’t get confused about it. It will be right step for sure…
Anurag said
recently i completed oracle dba course ,i post resume with 2 yaer exp in oracle dba then i get call from ericsson my designated id programmer and with real exp is 1.7 year so what to do
i ask to someone who told me ,if u get fake exp then u debarred from company and they blacklisted
u can give me some guide
Pavan DBA said
please email me to mymailbox.21@gmail.com
sau said
Hi Pavan
Hope you are in good health. I have few questions regarding different topics.
1.What will happen if I run catpatch.sql not in STARTUP UPGRADE mode?
2.I have two ORACLE_HOME. One for 10.2.0.1 and another for 10.2.0.4 (After applying patch set). 10.2.0.4 ORACLE_HOME has no database. I am planning to create few databases under 10.2.0.4 ORACLE_HOME. Is it necessary, to run catpatch each time after creating a new database?
3.Why oratab and oraInst.loc files are created under root user? If I change their ownership to oracle user, will it cause any problem?
4.Is quiescing/suspending a database before backup an option?
I look forward to receiving your reply. Thanks in advance
Sau
Pavan DBA said
1. First of all I doubt whether oracle will accept to run it. Even if it is, proper information may not be recorded in the data dictionary and oracle may not apply patchset correctly
2. not required
3. it won’t be any problem
4. nope. we should not use them before taking backup. “begin backup” is the only option to use
sau said
Thanks Pavan
Sau said
Hiii Pavan
Hope you are in good health. Thank you very much for answering my questions &
clearing my doubts.
Today i have few queries regarding User Managed Hot Backup
1.After executing ALTER TABLESPACE … BEGIN BACKUP, What will happen to the
ongoing transaction related to that particular tablespace?
2.What influences the time taken for the ‘alter tablespace begin backup’
Statement?
3.Can we take User Managed Hot Backup using “ALTER TABLESPACE OFFLINE”
command?
Hope to hear from you soon.Thanks in advance
Sau
Pavan DBA said
1. Ongoing transaction will continue without any issue because DBWR will still write the dirty blocks during hotbackup. Only datafile header will be freezed.
2. I have not got your question clearly. can you explain a little bit plz?
3. we can take, but that is not a hot backup because you are making tablespace offline which is nothing but downtime for users who are accessing it. so its not a preferred way
Sau said
Hiiii Pavan
Thanks for your reply.
Issuing “alter tablespace begin backup” across every tablespace is taking about 10-15 minutes.Why is it taking so much time? (This question is related to
my 2nd question)
For example:
SQL> alter tablespace users begin backup;
After waiting for 10-15 minutes, it returns ” Tablespace altered.”
SQL>
Regards
Sau
Pavan DBA said
may be huge transactions are hitting the database which is making oracle slow down in making datafile header to go for freeze state
Sau said
Thanks for your efforts to share your knowledge and experience with Oracle professionals . Please keep doing that
Pavan DBA said
thank you for the comments and yes i will be doing this….
Jeremiah Moses said
Hey Pavan,
I knew you were writing a blog but today is the first time i saw you website. Been a long way since you were sitting next to me in JCE for 3 years you hardly spoke 1 full sentence a day 😀 now here you writing so much. Keep it up m8 !
Pavan DBA said
Hey Jere,
Thanks macha…
yes man… i used to be very shy and confined at that time. But grown up a bit now 😀
Good to see your comments in my blog. I am following you on FB even though I nvr intereacted directly….
Will start be in touch with you….
sudheer said
Hi pavan anna,,
Struggling for getting job for the post of ORACLE DBA as a fresher.
Please send or post details for fresher.
Could you let me know the vacancies for fresher.
Pavan DBA said
hi sudheer, any job vacancies, i would be posting in my blog. so keep on watching it. also, recently i posted some fresher openings in CTS. if you haven’t seen that yet, please apply immediately.
Sau said
Hiiii Pavan
Hope you are in good health. I have tow queries regarding Log Switch.
1) If a Log Switch doesn’t happen for a long time, what will happen?
2) If Log switches happen frequently, What will happen?
With Regards
Sau
Pavan DBA said
Hi Sau, thanks. I am doing good and hope the same with you.
1. If log switch not happening, that means redolog file is not full. so in this case, there is nothing to worry until users complain about some issue. in that case we can check in alert log file
2. if log switch occurs frequently, then it would cause burden on the DBWR and CKPT processes as they need to write the data to datafiles and controlfiles. this may have impact on performance of the db
Sau said
Hiiii Pavan,
Thanx for your reply.
I have read somewhere that if a log switch doesn’t occur for a long time then there
may be chances of losing data when the redo log file get corrupt. Is it true?
Is there any impact for standby DB, if the primary databases have
ARCHIVE_LAG_TARGET parameter enabled?
With regards
Sau
Pavan DBA said
Yes, we would be loosing data if the file is corrupted and log switch is not yet happened. But to avoid that, we are going to have multiplexing of redolog files into different disks. In that case, even if one member is corrupted, other member still will be there to help out.
that is why one more reason, why oracle will recommend to have less size for redolog files (to avoid corruptions and go for frequent log switches)
ARCHIVE_LAG_TARGET limits the amount of data that can be lost and effectively increases the availability of the standby database by forcing a log switch after the specified amount of time.
A 0 value disables this feature.Values larger than 7200 seconds are not of much use in maintaining a reasonable lag in the standby database. The typical, or recommended value is 1800 (30 minutes). Extremely low values can result in frequent log switches, which could degrade performance; such values can also make the archiver process too busy to archive the continuously generated logs.
Thiru said
Hi Pavan,
I just seen your “about author” and surprised to see the name Jerusalem over there..Are you graduated from Jerusalem College of Engg,Chennai?
I too completed my degree over there and now working as a Oracle (Apps) DBA in an MNC.
Regards,
Thiru
Pavan DBA said
Hi Thiru, yes I am graduated from JCE in the year 2004. Good to hear that you are also from same college
Sayba said
Pavan,
Kindly provide an accurate answers to the following questions pls,.
Question 1:
1.”Because of DBA error (before we started obviously!), an important database was created with a 2k block size, and as it is physically on a SAN with an 8k write chunk, we are dealing with unnecessary performance implications.
Please prepare a detailed, technical (how you plan to do it) _and_ logistical (what you plan to do, in what order, when and how long you think it would take) project plan for our conversion of our database from a 2k block size to an 8k block size.
For estimation purposes, a full database export of this database takes 12 hours, and we estimate a full database import would take about two to three times as long because of index re-creation time. Assume our cost of down-time is $10,000 per hour and as a result it’s very important to come up with methods of reducing downtime. Needless to say, 36 hours of downtime, at a cost of $360,000 is completely out of the question. Obviously, with such a high cost of downtime, we have properly resourced the environment in terms of disk space on the SAN. As well, we have a spare server available if necessary to further reduce the downtime. ”
Question 2:
2.Use the link following this question to download the interview.dmp
Using the INTERVIEW schema:
Table USERS
columns:
User_id (PK) (generated via a sequence)
Email
Gender
Age
Name
table SUBSCRIPTIONS
columns:
SUbscription_id (PK) (generated via a sequence)
user_id (UK) (FK from users)
subscription_type (UK)
active_indicator
table TRANSACTIONS
columns:
subscription_id (PK) (FK from subscriptions)
action (PK)
timestamp (PK)
sample data:
USERS
user_id email gender age name
1 a@a.com m 30 rob
2 a@a.com m 31 robert
3 b@b.com f 18 lucie
4 b@b.com f 22 lulu
5 c@c.com m 10 kim
6 c@c.com f 18 kim
7 c@c.com f 08 kim
8 d@d.com f 18 JJ
9 d@d.com m 22 Jay
10 e@e.com f 88 Bill
11 e@e.com f 88 Will
12 e@e.com f 60 Will
13 f@f.com m 70 George
subscriptions
subscription_id user_id subsciption_type active_indicator
1 2 Magazine Yes
2 3 Music CD No
3 3 Magazine Yes
4 3 Video Yes
5 8 Magazine Yes
6 9 Video Yes
7 10 Magazine No
8 13 Magazine yes
transactions
subscription_id action timestamp
1 Renewal 2002-sep-10
2 Renewal 2002-Jan-01
2 Cancellation 2002-Feb-01
3 Renewal 2002-Aug-20
4 Renewal 2002-Aug-01
4 Renewal 2002-Sep-01
5 Renewal 2002-Aug-01
6 Renewal 2001-Sep-01
7 Renewal 2002-Sep-01
7 Cancellation 2002-Sep-10
Type of business:
We are a subscription company where people signup to received products
like CDs, books, magazines, etc. We always try to market new
subscriptions to our existing client base, but having millions of
customers of which many use the same email address we like to send are
promotional email’s once.
QUERY:
Some assumptions will need to be made. Please list any such assumptions.
Generate a list of unique email addresses with the latest name, gender
and age for a user with that email
The selection criteria limit the list to users which never subscribed to
anything; or;
users with inactive subscriptions; or;
users with active subscriptions that renewed between Sep 1st and sep
30th of any year
answer should be:
a@a.com m 31 robert
b@b.com f 22 lulu
c@c.com f 08 kim
d@d.com m 22 Jay
e@e.com f 60 Will
Question 3:
3.using the INTERVIEW SCHEMA
We require a PL/SQL program to be written that will take the data in the TSOURCE table and 1. insert rows not currently in the TDEST table and 2. update TDEST rows with a matching KEYVAL value with the data in TSOURCE.
Please write the program so as to maximize overall performance and efficiency.
Be sure to carefully rollback your work after every attempt at running your program so that you have a chance to try again!
Bonus points if you can measure for us exactly how many buffer gets your pl/sql program uses using tkprof.
Question 4:
4.Please install statspack/perfstat to take performance snapshots every 15 minutes on the 15 minutes except during our batch window of midnight until 7am, during which time we would like performance snapshots taken every 2 hours at the top of the hour (midnight, 2, 4 and 6).
I am really interested in the scheduling part not the content of the perfstat reports themselves
Pavan DBA said
As you have not mentioned your OS version and database version, I am assuming it as 10.2.0.4 and OS as some unix flavour.
1. If your database is 9i or above, you can use non-default block size tablespaces, in which case we don’t need to do conversion at all. All we need to do is just move the tables to new non-default block size tablespaces which would not take huge downtime.
as you mentioned export is taking 12 hours, I would like to know if it is traditional export you are talking about or datapump? and what is the database size? If it is traditional export, then we need to check the time taking with datapump also. Surely datapump will run faster than normal export with the help of parallel and other options.
Also, we can do export/import of tables and other objects skipping indexes. later after import, we can create indexes. this will reduce the import time.
2. I have not understood your 2nd question. please explain me in details
3. I am not a perfect programmer in PL/SQL, so any developer can help you on this
4. If your database is 10g version, then you don’t need to use statspack instead you can use AWR report which will run every one hour automatically
If it is statspack, you can try scheduling through dbms_jobs or using spauto.sql script as perfstat user
please do mention versions so that I can help with some accurate answers
Zeeshan Girach said
Hi Pavan,
This is good to see your dba profile and hope to learn from you in near future. I am from karachi pakistan and completed my training of OCP from an recognized institute and about to attempt my first paper of SQL in coming month. These days m practicing oracle 10g on TEST environment in a pharmaceutical company.
Till now i practiced DDL, DML, TCL and DCL statements but the problem that i am having is m week in concepts of table space, pfile, spfile, user space, schema, constraints, instance, data file etc. operating is fine i can operate but when it comes to the concepts of technical brief i am dumb. How can i improve and can clear my basic concepts apart from searching on google and what line of action should i follow to practice in easy manner to get improve quickly and to be able to operate maximum amount of data in short period of time.
Best Regards,
Zeeshan Girach!
Pavan DBA said
Hi Zeeshan, you can read a very good book called “expert 11g administration” by sam.r.alapati which is easiest way to learn dba concepts
vikas said
Hi sir,
i am trying to install oracle 10g on RHEL 6 but i could not do it
so will you share some document to install oracle on RHEL 6.
Pavan DBA said
hi vikas, i think oracle 10g is not supported on rhel 6. so please try with 11g r2
Ahmed said
Hi Pavan,
This is ahmed, I have heard lot about you from my friends.
Just wanted to ask you about the difference between an oracle client installation and oracle software installation.
If i install oracle client then i dont think it will have database in it. I guess we need to connect it to a different server to get the access.
Could you please tell me the difference in installing oracle client and oracle software itself and also where and why do we use oracle client?
Thanks in advance for your help. you are doing a very nice job. God Bless you
Pavan DBA said
Hi Ahmed, yes. your view regarding client and database software is correct. client s/w will not have database, so if we install client s/w, we cannot create database.
Oracle database software will be used in DB server to create new databases (as we already know).
Suppose we have a java application on server A (all java code will be put in this server). We have created database on another server B (here we will install database software and created database). Now if this java application (running on A) need to connect o database (running on B), we need to install oracle client s/w on A.
Installing client s/w is almost like database s/w. after installation, we need to configure TNSNAMES.ORA (in our case on server A) and that will connect to database (in our case B) using listener which runs on B.
hope this gives u some idea
Ahmed said
Thanks for ur quick reply. I Understood now. Appreciate your help.
Pavan DBA said
you are welcome…
chandu said
Hi Sir,
Good Day,
What is the use of v$timezone_file,If it is lessthan 4 what we have to do?Bcz presentely i am working in patching & upgradation team.
How to resolve this one.
Appreciate your help.
Regards,
Chandu
Pavan DBA said
this link will give some idea about that
http://lifedba.wordpress.com/2009/12/29/timezone-file-version-warning-when-upgrading-oracle-database-from-10-2-0-1-to-11-1-0-7/
Sayba said
Pavan,
Iam still waiting for the replay to my question which I posted you yeaterday.
Pavan DBA said
Hi, Sorry I am on vacation since last 3 days. so couldn’t reply you. I replied it now….
suganya said
Hi Pavan,
I have a requirement to convert 9i database to 11g database with zero downtime.
Could you let me know whether this is possible? if so, can you elaborate the steps.
Regards
Suganya.S
Pavan DBA said
Hi Suganya,
I couldn’t understand what you mean by convert? do you mean upgrade or migration?
upgrade means moving to 11g on the same server
migration means moving to 11g on diff server.
If you are doing upgrade then zero down time is not possible. But if you are doing migration, then it is possible.
please elaborate your requirement so that I can give better suggestion and steps to do that
sayba said
Pavan,
Thanks for the replay. Let me explain you more about my professional journey,,basically I have been in this IT industry as an oracle DBA from last 4 years.But unfortunatly the account where I used to work for long time does not gave me an oppertunity to explore my skills at all areas of oracle DBA coz of no work. As a result of which when I come out from the company my knowledge level was zero (fit for nothing).
Again I struggled and able to find DBA job in another company,,but the actual thing is iam not interested in technical work coz,,,,
1.Iam not good at logical thinking 2. Iam very very poor at programming whetehr it is shell or PL/SQL or Database 3.Iam reaching to 40yrs
Based on the above constraints please suggest me what I have to do to carry out my journey in an IT industry ?
Basically ,,Iam an ITIL certified with 8+yrs of experience in IT industry with relavent as 4yrs in Oracle DBA.
Kindly suggest me what I have to do to proceed further ?
Pavan DBA said
Hi,
If you have perfect hands on with DBA topics (as you said you didn’t got much chance to work on all concepts in your earlier Oracle exp), you can get the job with right kind of project within no time.
Moreover DBA will not have any technical work, so you need not to worry about programming etc. So, I suggest to get home practise on RMAN, Cloning, Upgradation, Patching, Dataguard, ASM etc and you will find the best job for you
Balakrushna said
Hi pavan Sir
I have dout in older export and import utility
I have taken One dump file of table and Consistent=N before that I have updated that table but I am not given the committed.
While I export to another schema the dump file contains the uncommitted data also.
so i have dout in what does Consistent parameter will do in oracle older export ?
I think that consistent parameter is for the export dump file will take only previous image block am I wright or wrong ?
if I am wrong please explain me ?
Pavan DBA said
Hi,
Please go through these links
http://docs.oracle.com/cd/B10501_01/server.920/a96652/ch01.htm#1005545
http://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:21545894805637
Sayba said
Hi Pavan,
I have gone through your blog first time looks like very interesting. My question is iam not at all good at Programming side even writing/understanding a small database script or RMAN script will be a tough task for me.I wanted to pursue my career in SQL SERVER DBA which I came to know a bit easy to learn and no Programming knowledge required.
Do we really need any programming knowledge or .net or do we need to read scripts used where we need to modify the production server issues in SQL SERVER DBA?
Currently I want to switch my career from oracle DBA To Peoplesoft DBA or Sql Server DBA coz I find it difficult coz of my zero PROGRAMMING KNOWLEDGE.
Kindly advice.
Pavan DBA said
Hi,
If you can put little effort in learning shell script, its easy only. So I recommend to try that.
As you said, SQL Server DBA is quite a bit easy as administration of it can be done using GUI tool. But, may be there also you need some logical thinking (I cannot call it as programming as programming means wirting code for front end applications). We need to write some scripts there also.
As I am not having pretty much idea about SQL Server DBA, I cannot comment much on that…
ravi kumar chowdary said
Hi sir, i am ravi kumar chow dary.u r student.i want know about oracle server & oracle client..what is the diffrence between oracle server & client.
right now i installed oracle client in my PC.i want install oracle server in my PC
plese tell me
Pavan DBA said
Hi Ravi,
Oracle server is nothing but database. Client is a software which we will use from applications to connect to database (when database is residing on another machine than application server)
ravi kumar chowdary said
Hi sir, this is ravi kumar..i learn core dba on linux plotform (10g version) .right now my organization in windows plotform (9i version).what is the major diffrences between two things.how to work on windows plotform ??
tell me sir.
Pavan DBA said
Hi Ravi,
the basic administration activites will remain same even in windows. But some activities which need OS help will change. for example, to start the database you need to make sure even service is running in services.msc file. etc
Create a test database on your home machine (if possible) and get hands on. If any doubts, plz contact me
Ravi kumar chowdary said
Hi sir,
This is ravi kumar.i want know windows plotform dba comands like (to take cold backup & hardback).my oraganization is windows plotform.
i know Linux plotform comands.plese give me sir.
Pavan DBA said
see this link – http://www.computerhope.com/msdos.htm
ravi kumar said
Hi pavan sir ,
i am checking in that website,in that there is no information regarding oracle dba(windows plotform) comands..i don’t have sufficient knowledge on windows plotform.i don’t have how to work on windows plotform.
and one more thing sir.in single system (linux) we install oracle 10g client & server in same machine.
tell me
Pavan DBA said
hi ravi, for windows we don’t have specific commands related to oracle. all oracle commands in linux will work as it is in windows also (for eg lsnrctl, tnsping, exp, imp etc).
regarding your question, yes we can install, but there is no use because server software already will have all the files related to client software
Ravi kumar said
Hi sir,
i am ravi kuamr.u r ex-student.i want know windows plotform oracle dba comands..i learn dba linux plotform comands.i don’t know how to took export &import database.plese send me sir
Pavan DBA said
Hi Ravi, as i mentioned in earlier comment, commands are same in windows or linux. exp, imp etc are oracle commands, so on any OS those will remain same.
Ravi kumar said
Thank you very much sir
anil said
Hello Pavan sir,
I want full details of TOP FIVE EVENTS and ALL HIT RATIOS .why events will be occur and how solve ,Can you please help me by providing the all details?
Thanks ,
Anil.
Pavan DBA said
Hi Anil,
See these links
Click to access statspack_opm4.pdf
Click to access statspack_tuning_otn_new1.pdf
for more info read this – http://docs.oracle.com/cd/B19306_01/server.102/b14237/waitevents003.htm#BGGIBDJI
prabhudba said
hi sir,
can we do oracle installation in silent mode i’m interested in learning it please help me out with any doc
Pavan DBA said
Hi Prabhu,
You can use below links
http://www.dbapool.com/articles/0803200801.html
http://oracleinstance.blogspot.com/2010/07/normally-we-installed-oracle-using-oui.html
In realtime, we won’t do slient installations mostly
ravi kumar chowdary said
hi pavan sir,
i am ravi kuamr chowdary.u r ex-student..i learn core dba & appsdba..right now i got a job on sql server..i don’t have knowledge about sql server..pls give me breff discussion about sql server.right now i am in training.
Pavan DBA said
Hi Ravi,
Congratulations first of all….
I hope it is SQl Server DBA. in such case, it would be similar to Oracle DBA. SQL Server is the database from Microsoft. only difference is in the architecture and way of doing administration. As it is more GUI based, you will feel it is easy to manage.
teja said
Thanks for your reply on this Pavan.
Pavan Kumar said
you are welcome….
teja said
Hi Pavan, I need help on this. This entire task should be done on the production environment.
Task :
We have a two node rac now in our environment. But one node was down due to hardware problem from last 1 year.
Recently we ordered a new server for Database. It came to our site now. So first i have to remove the bad node from the existing rac and then i have to add the brand new node to the existing rac.
But the problem is:
Type of the brand new server which is to be add is : T3-1
Type of exixting dbserver in rac is : T5240.
Details of existing rac is:
1) Oracle DB Version : 10.2.0. 4
2) OS : Sun Solaris 10 version 5/9 u7
3)Kernel Version : 144488-17
But the New server which is to be added will not support this “Sun Solaris 10 version 5/9 u7” os (including version). T3-1 server supports these os only: OS solaris 11 , solaris 10 10/9 and solaris 10 9/10.
My doubt here is, In this case shall we add this node to the existing RAC??? If Yes, My problem was solved, If not possible – Is there any possible way to add this node.???
Note : We have a one more T3-1 server which is in nfs server cluster( this is os cluster). In least cases we can remove this from nfs cluster and we can make a new 2 node RAC for DB using 2 T3-1 servers.Then we have to migrate the existing rac which is on only one T5240server to the newly made RAC of 2 T3-1 servers. In this case how much down time for DB is needed…?? Please help me on this.
I am Awaiting for you reply Sir…
Thanks in advance
Regards
Teja
Pavan Kumar said
As far as I know, always it is better to have RAC environment with same OS and same hardware. As you said the new server can support only solaris 11, then I assume it is not possible to have second node on that server.
So, the possible way is to remove that OS cluster server and make that as 2 node RAC and migrate the data. In this case, you may not need much downtime as you can do RMAN cloning from single machine to RAC machine.
Steps for cloning single to RAC machine is available in a note in metalink. you can browse for that.
Above all, I suggest to raise SR with Oracle support and do this task (since it’s production) as they can best tell the easiest way….
tangy said
Try building a standby system from existing rac to new 2 node rac and make a switch over. This should have minimum downtime than expected. please give a test before implementing this.
Pavan Kumar said
sorry, i didn’t got your question here….
ravi said
HI PAVAN SIR,
I AM Ex-KANNA INSTITITE STUSENT.I WANT INSTALL ORACLE 9i OR 10G (WINDOWS) IN MY LAPTOP.IN MY LAPTOP OS IS WINDOWS 7.WINDOWS 7 IS COMPATIBLE 9i & 10G.
PLESE TELL ME
Pavan DBA said
Hi Ravi,
9i is not suitable, but 10g can be installed
teja said
Thanks thangy for your note id
teja said
Hi Pavan,
Good Morning.
I have seen your active participation on this and it is very pleasure to me on this.
I have a very big task infront of me in coming days. Will you please help me on this.
Task : We have a 2 node rac now and only one node is up and running now since last 1 year. ( The other one was of hardware failure ).
Now 2 new DBservers came for our project and I have to setup rac on these two new servers and after setting up of this new rac environment successfully, then i have to move the old rac ( ie.. running on only one node) to the new rac.
Os version : Sun solaris 10
DB Version : oracle 10.2.04
RAC to be setup : 10G rac
Will you please guide me with the basic procedure and steps orally, So that i will do my work around on this later.
It is very pleasure to me if you give me any doc id on metalink.( doc id needed for setting up 10grac on solaris10 and for rac migration)
Pavan Kumar said
Hi Teja, already I have docs on configuring new RAC setup in my “important docs” page. you can refer the docs there.
May be those docs talk about linux, but steps would be almost same on solaris also.
you can also see this oracle link – http://www.oracle.com/pls/db102/to_toc?pathname=install.102%2Fb14205%2Ftoc.htm&remark=portal+%28Books%29
regarding migration, i need more details to confirm the procedure. plz chat with me when i am online. but most of the times, migration will be done using expdp/impdp
tangy said
Hi Pavan/Teja
Have you ever tried using convert datafile , convert tablespace and convert database commands in rman which might help in migrating the database faster. Datapumps definitely help you when your database size is manageble.
Tangy
Pavan Kumar said
Yes, I too agreed with Tangy that datapump is helpful for less DB size
tangy said
Best oracle Note is : 414878.1
Pavan Kumar said
Thank you for providing this
vikas dharmadhikari said
Hi sir.
what is the difference between materialized view and snapshot?
Pavan Kumar said
Snapshot is the name oracle used till 8i and from 9i we are calling it as materialized view. difference is MV will use MV log mechanism in order to refresh data. for more details go throguh oracle documentation
Dilip said
Hi Pavan,
I am Dilip from chennai, working as Oracle apps DBA having about 1.8 yrs of experience.. I agree its easy way to get placed in campus but tough to landup with fresher jobs as DBA. Your post brings lots of hope and confidence for those want to get sneak through doors of database administrators.. 🙂
I join here today to get some exposure, knowledge sharing and tips from you…All the very best..
Regards,
Dilip
Pavan Kumar said
thank you Dilip
vemuri said
sir what is the difference between synchronous I/O and asynchronous I/O and what is the relation of them with oracle
Pavan Kumar said
Synchronous IO means OS will wait for one writing task to complete before it starts another. where as asynchronous IO will start another process while first one is in progress. When asynchronous IO is enabled, either DBWR or LGWR can write data fastly which avoids IO bottlenecks
see this – http://www.oracle-base.com/articles/misc/DirectAndAsynchronousIO.php
vikas dharmadhikari said
hi sir
i have one question that some dynamic performance views works at nomount
ans mount i just want to know from where these views fetch the data
Pavan Kumar said
These views will fetch the data from X$tables which will get initiated in the nomount state itself
vikas dharmadhikari said
thank u sir…………
tangy said
Excellent question, It definitely retrieves information from X$tables, it could be proved by running explain plan on the query. But where are these tables stored and retained in no mount state. I hope it should be definitely in the SGA.
Mahesh said
Great to See you
Mahesh
vemuri said
hi sir,
where does scn number stored in redologfiles.How to find it?
Pavan Kumar said
SCN number will be stored in redo entry in one of its column. In order to read redo entry we need to use LOGMINER utility. we will use dbms_logmnr package. for syntax and other details, just google it
vemuri said
hi sir,
I have only hotbackup and i lost all my redolog files then how to recover them.plz give me the solution
Pavan Kumar said
you need to follow below steps
1. shutdown immediate
2. startup mount
3. recover database until cancel;
4. alter database open resetlogs;
when you use resetlogs option, oracle will create new redolog files and your log sequence number will be reset from 1 onwards….
vemuri said
thanks sir for the solution
Pavan Kumar said
You are welcome
santhosh said
Hi sir
I’m santhosh
till now i did’nt go through your blog
but after seeing this replies and comments
hope ur blog was plenty enough to become a good DBA
Thank You
Pavan Kumar said
thank you santhosh for your comments. still am trying to post so many articles
chandrashekar G said
Dear Pavan,
I am getting an error while running EXPDP.
Please Help me
C:\>expdp system/manager@CNBKRRB1 full=y directory=test_dir dumpfile=expdp.dmp logfile=expdp.log
Export: Release 10.2.0.4.0 – Production on Wednesday
Copyright (c) 2003, 2007, Oracle. All rights reserved.
Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 – Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
ORA-39002: invalid operation
ORA-39070: Unable to open the log file.
ORA-29283: invalid file operation
ORA-06512: at “SYS.UTL_FILE”, line 488
ORA-29283: invalid file operation
Pavan Kumar said
Hi Chandu,
It is due to a bug in windows. see this
http://fritshoogland.wordpress.com/2010/01/20/using-datapump-on-windows-to-write-to-a-share/
chandrashekar G said
pavan sir,
We are using AIX platform….
Pavan Kumar said
may be your database is residing on AIX, but you are trying to take export backup on windows. (i can see export cmd from C: prompt in your query)
so it might be a bug. or also check what is the value that was set to UTL_FILE parameter in your database pfile or spfile and you can change that to ‘*’ which means you can access any location for your database. for more info on UTL_FILE, refer to google
sanjay pogul said
Good Evening Sir,
My name is Sanjay. Sir, I am an OCP Certified DBA. I am looking for the job of DBA as fresher. Being a fresher & non-IT background, I am not getting any interview calls. I don’t know what to do. Sir, can you guide me please?
Pavan Kumar said
Hi Sanjay,
getting a fresher DBA job is tough task, but never loose hope and keep on trying. Donno if you had done this already, if not post your cv to all job sites and daily login and apply for the jobs suitable to you….
chandu said
hi pavan,
Whenever i enable change tracking file that time i will get the below error..pls provide the solution..
ora-19760 error starting change tracking oracle
Pavan Kumar said
Hi Chandu, can you tell me what more information is there in alert log file. also is there any trace file created? if so have you examined that?
suman said
hi sir,
I got an error ora 01157 error while changing the locations of all my files to a new mount point .
I have moved all the files to new location and edited the pfile .Now when i started my database it just went to mount stage and not able to open showing the above error.I am using 10g database.Are there any other locations to change.
Please give me explanation regarding this scenario
Pavan Kumar said
Hi Suman,
after moving datafiles and redologfiles, did u ran relocation command in mount stage? for example
SQL> alter database rename file ‘old loc’ to ‘new loc’;
If not plz do it. you edited pfile only for controlfiles. but to make oracle understand about datafiles and redologfiles, you need to run above command for each and every file. then you can open your database
G .chandrashekar said
Hi Sir,How r u sir,
Sir pls provide script regarding genarating the AWR report(I need to genarate every one hour) so pls provide the script..
and one more thing is i want shift the archive logs from primary to standby but primary & standby both are different environments how to shifts the archives.
Pavan Kumar said
Hi Chandra,
I am fine & hope the same with you
1. AWR itself will take snaps every 1 hour. so there is no need again to run it for every one hour. The only script we use to generate report is ORACLE_HOME/rdbms/admin/awrrpt.sql
2. I am not sure why you need to shift archives. when you have dataguard env, archives will get shipped automatically… can you explain a bit more on this?
Chandrashekar said
hi pavan,
If archives are not shifting to standby due to n/w problems some other problems,in that time i will disable the DG at Standby side and shift the archives,i know the process of that one but if it is diffrent env what is the procedure…
Pavan Kumar said
I am not sure why you are doing it manually? in case if you have network problem, oracle will use the help of FAL (fetch archive log) process to take care of this. so, no need to manually do the things. to know more about FAL, read oracle documentation
G .chandrashekar said
Hi Pavan,
Neeed script to monitor CPU Utilization…
Pavan Kumar said
cpu utilization can be found using “top” command in unix and through task manager in windows
Chandrashekar said
In RMAN is it posible to increase the retention policy?,If it is posible pls explain me how to increase and what is the command..
Pavan Kumar said
yes it is possible. when you type show all, by default it gives you retention policy to redundancy 1. you can change that like below
RMAN> CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 28 DAYS; – this is in case you are using recovery window
RMAN> CONFIGURE RETENTION POLICY TO REDUNDANCY 30; – this is in case we use redundancy
G .chandrashekar said
Hi Sir,
How to enable block change tracking in rman,Is there any parameters changing required in controlfile????
Or in sql directely we can use this command only..
SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;
Pls explain me what is main purpose in background how it will work…..????
Pavan Kumar said
yes it is directly to run that sql statement. there is no other parameter to set for this.
what happens in background?
1. when block change tracking is enabled, when ever a block is change the corresponding block id is written to a file.
2. when RMAN backup is initiated, rman process direcly reads this file and will start taking backup of those blocks.
this helps in reducing the backup time as it will not compare block scn with last backup
chandu said
thank you pavan ge….
G .chandrashekar said
Hi Sir,
What are the mandatory parameters in DATA GUARD,what is the use of those parameters,and how to transfers the datafiles,archive shipping…
Pls explain me briefly…
Pavan Kumar said
Hi Chandu, I have a document attached in “Important Docs” page for physical standby database creation and dataguard broker. please check that and get back to me in case of any questions
Chinthala Mahenderreddy said
Hai sir,please send some details about crontab with some simple examples.How to execute oracle jobs from crontab?.
Pavan Kumar said
again, google will help you alot….
Nitan Jandial said
What is cron?
Actually it is called ‘cron daemon’. Cron is an automatic task machine. You will use it on your Unix or Linux operating systems for doing some tasks at specific intervals with out your intervention every time. You set the clock and forget. The cron daemon runs the work for you.
What are the components of cron?
=Field====Value====Description=
minute====00-59====exact minute the cron executes
hour======00-23====hour of the day the cron executes(0 means midnight)
day=======01-31====day of the month the cron executes
month=====01-12====month of the year the cron executes
weekday===00-06====day of the week the cron executes(Sunday = 0, Monday = 1, Tuesday = 2, and so forth)
command===Special==complete sequence of commands to execute
Examples how to set cron:
If you have installed a cgi script in your cgi-bin directory called members.cgi and wanted to run this program each night as 11.30 PM as in above example.
You would setup the following crontab line:
30 23 * * * /home/username/www/cgi-bin/members.cgi
30–represents the minute of cron work
23–represents the hour of the day
The * represent every day, month, and weekday.
If you want to set the cron job every sunday at midnight 11.30 PM then it would be like:
30 23 * * 0 /home/username/www/cgi-bin/members.cgi
0–represents the Sunday.
If you want the cron job to run at 1:00 and 2:00 A.M then you can set it like:
* 1,2 * * * /home/username/www/cgi-bin/members.cgi
This runs your cron at 1 and 2 A.M every day, every month and every week.
If you want to run the above task only from Monday to Friday then set it like:
* 1,2 * * 1-5 /home/username/www/cgi-bin/members.cgi
Setting up the cron:
You will be in one of these situations.
ONE:This would be your first cron tab function.
SECOND:You already have cron tab file on your server running one or more cron functions for you.
Hope this would help you.
Regards
Jandial
Chinthala Mahenderreddy said
Hai sir.Please send some useful suggestions(how to approach) to get Oracle DBA job.
Pavan Kumar said
Hi, the only way to get a DBA job is to practise a lot and keep on reading theory. You can refer to “Expert Oracle administartion” book by Sam.R.Alapati which gives good knowledge.
Jeet Padhee said
i wanna follow u sir..
may allowed please..
you have vry good n nice style of teaching
Chinthala Mahenderreddy said
what is the snapshot too older?
Pavan Kumar said
it is a error which oracle throws to a select user if it doesn’t find either new data in datafile and old data in undo. it is famously called as ORA-1555 as you know. this occurs because of less undo tbs size or frequent commits etc
Unmesh said
Hello Mr. Pavan,
I have gone through your blog and your knowledge on DBA is exceptionally apar from other DBA bloggers.
Like you i am also very much interested in pursuing my career in DBA field, but couldn’t find any opportunities.
Can you please help me out.
Thanks in Advance.
Mail me @ unmeshshah1988@gmail.com
Awaiting for your email.
Pavan Kumar said
Hi, good that you wann to be DBA. welcome !
u can chat with me on mymailbox.21@gmail.com for all your questions
Unmesh said
Hello Mr. Pavan,
Thank You for your generous reply.
I have added you in my chat section of gmail email address.
chandrashekar said
Hi pavan ge,
this is chandrashekar,i have done oracle course recentely last 3months back after that i attend interviews i stragulled there bt finally i got the gob in WIPRO last week only.But i dont have practical knowledge,can u guide me how to gain the practical part,enviroment of the realtime really my body is sheking whenver i think that company….
Pavan Kumar said
the smart thing about DBA is what ever you practised during course, same you will be doing in real time also. so be handy with all the topics which helps you alot
chandrashekar said
thaku pavan, and one more is thing what are the real time senarioes in datagard means(errors, realtime question like that…)Pls help me on this part,bcz i m poor in dataguard
Pavan Kumar said
anyone can explain scenerios only on their experience. if you got any errors whileconfiguring, u can tell them as the scenerios… u can refer to oracle documentation to get idea on dataguard
srinivas said
Hi pavan sir
i am proud to say that i am your student(kanna technologies),i am MCA 2010 passed out.I hav good percentages(above 65) but i hav less confident on me to get a job,so that i stayed in my home last one yr,now i returned to hyderabad now i really got confident that i can also get job and i am thinking that i choosen the best inst and best faculty to learn dba course in hyderabad.
Thankyou so much sir.
Pavan Kumar said
yes being confident will always helps us in acheiving the goals. happy that atlast you decided your path. WISH U ALL THE VERY BEST ! I am here always to help you in case your doubts are within my knowledge level 🙂
vk said
Hi machi,
I am a 2004 batch mca graduate(1 paper pending for a long time) unfortunately caught into the BPO domain for more than 3 yrs and I always wanted to become an dba. Now i have quit the job and finished MCTS certification in sql server to become sql dba but I am searching for more than 6 mths and I am unable to land in a job. Why there is no opening for freshers in the DBA field even though i have knowledge and I clear most of the interviews. Why do co’s expect with 2-3 yr exp. only? Please let me know what abt the chances of getting a job in hyd/banglore? I am almost fed up ! Sometimes i feel iam gonna fall into bpo again which i dont like at all. Whats the use of wkg without satisfaction?
VK
Chennai.
Pavan Kumar said
Hi Vinodh, you are definetly right. There is no reason for working if we are not satisfied. reg your question, why fresher DBA jobs are less? as always databases are critical to handle and contains important data, clients will look for an exp professional rather than a fresher(their feeling is unexp person may not take right decision at right time which is sometimes true).
But we do still have fresher DBA openings and it takes is time. Even I also started my career as fresher after struggling alot. I am send mail to you on what can be done next….plz check
Nisha said
Hi.
I am new to oracle,i have installed Oracle Database11g R2,Oracle Grid 11g R2
and these two i used Vmware and Oracle Linux 5.5.
Now i want to install Data Guard for my Rac so i read so many
notes and google for it but really i did not feel bad in any other
configuration like i felt bad in Data Guard configurations
so still i am not able to configure Data Guard if anyone plz wants to help me
contact me here is the email ID.
nn9887@gmail.com
thanks in Advance.
nisha
Pavan Kumar said
for dataguard document, you can refer to my blog section “importatnt docs” where you will get step-by-step doc and also a video tutorial.
banti said
Hi Pavan,
I am really impressed to see your blog.Its really a good source of sharing knowledge.I did Oracle DBA course and I want to know that what are the common errors facing by you people in real time scenarios.
Plz send me some real and common problems related space management,user management,backup,recovery,data pump(export/import),Cloning,Performance Tuning,Upgardation,Migration with ORA-XXXX and its solutions.
Thanks & regards,
Banti
Pavan Kumar said
Hi Banti,
whatever the technical articles I posted, all are the common problems we face. I will be keep on posting so many others. Do watching this blog.
Nagesh said
Hi pavan,
I ve done oracle DBA 10G nd OCP certified,presently im working in govt sector from 10months but only involved in monitoring database so i looking fr a change in job .. at present no openings fr freshers SO can u nplz suggest me wat to do….
Pavan Kumar said
as you are close to a year, you can start searching with 1+. ofcourse chances are less, but not impossible. even being in current position, you can self learn n practise to attain most knowledge
Munna said
Pavan,
I need the steps to upgrade the db from 10.2.0.2 to 10.2.0.4 and from 10.2.0.4 to 10.2.0.5 in both silent and manual mode.Please share ASAP.
–Munna
Pavan Kumar said
hi munna,
when doing any upgradation, it is must that you follow oracle upgrade guide instead of going or depending on regular ones which you can get from many websites.
you can download 10.2.0.4 patchset from my oracle support (metalink) which contains readme.html file. this file will give details on how to upgrade in both the ways you asked for.
Pavan Kumar said
also it is same for 10.2.0.5. you can directly upgrade from 10.2.0.2 to 10.2.0.5
Munna said
thank you..
venkata santhosh kumar B said
Hi Pavan,
This is santhosh, a 2009 B.Tech pass out under the discipline of computers. I have done DBA course perfectly. So, can i have opportunity for a break in my career. I think you can guide me for a best career.
Pavan Kumar said
hi santhosh, i can say DBA fresher jobs will be less but not impossible ! so plz keep on trying and post your cv in every job site you come across. also if any openings that i would know, surely i will be posting it here. so keep watching my blog
Younus said
One of my user has created new datafile in t1 tablespace but the user is not able to insert the data or we can say not get stored data in created table what is the solution of this….
Plz help me out…..
Thanks…
Younus
Pavan Kumar said
first we need to check in alert log if there is any error for why data is not been written to file. also need to check whther the datafile added correctly. based on that we can take action. i had never seen such thing till now, but if get it will be quite interesting !
Younus said
hi Pavan thanks for rply
But that is not the answer of my question !!! i mean alert log file has the information about that datafile and the datafile is also added correctly ….
And one more thing how many standby destination we can set in primary parameter file “like destination of archives”…
Pavan Kumar said
ok, what is the error msg users are getting while inserting the data? may be based on that we can analyze more.
regarding, standby destinations, we can have 9 till 10g and 29 in 11g
Naveen Bangari said
Hi Pavan,
Your blog is becoming a lot day by day (as expected)…its really helping a lot. I posted a comment on your performance tuning related category regarding sessions and process.
Recently i ran a script aflobbld.sql which is to create fnd_lobs_ctx index in Oracle Apps 11i…the script ran for more than 24 hours…so we killed the session using “alter system kill session..” but when we tried to run the same script again this script is waiting for the “library cache lock” held by previous session(which is already marked as killed)…how to get this lock cleared with out bouncing?
Can you please help me on this?
Pavan Kumar said
Hi Naveen,
Library cache locks will occur when the same object is being accessed by some one else. have you run this script in non-peak hours where there is no user activity? If so, there could be some sessions still holding the lock which you can find using below query
select saddr from v$session where sid = ;
also, Library cache lock is exposed via x$kgllk, dba_kgllock, dba_lock_internal view. so check in those views.
rajesh said
hi
I am rajesh from banglore.this block is very nice,it is very useful for all.i am 2010 fresher i have done oracle DBA,RAC.i want learn more knowlegde from you.i hope i am waiting for u r respond.
thank you
raj
Pavan Kumar said
hi rajesh, first of all its not block, its blog 🙂 (just kidding)
let me know in what way i can help you to attain more knowledge…
prathap said
hi pavan garu,
this is prathap. i would like to do the job in DBA side but i didnt have any experience in that field but can u give any suggestion me for real time scenarios. now i am applying to the oracle dba positions face interviews but ilittle bit difficult to me facing the questions. ac
Pavan Kumar said
Hi Prathap,
please chat with me at mymailbox.21@gmail.com. I need to ask you few q’s and then can guide you accordingly
anand said
hi pavan,
this is anand ,i have seen ur blog this is really amazing .now am being trained as an oracle apps dba in hyd , i dnt have any experience till now but i want to get recruited as a real time expert for abt 3+ , do u have any suggestions for me plz .
best wishes,
anand
Pavan Kumar said
you can chat with me @ mymailbox.21 in gtalk. i can guide you…
Sudhakar Reddy said
hi dude..hw are u..worthful information pavan..your blog is always inspiration to me..give me a chance to attend ur classes, on next visit to hyd surely wl meet, blocking your appointment now itself 🙂
Sudha.
Pavan Kumar said
am gud buddy and expecting same with you. thanks for your words, but i am still trying to understand about oracle. for you, my schedule is always vacant dude…but donno if u can able to meet others than my sister :-))
Shah said
Greetings Mr. Pavan,
Glad to view your blogs….
Pavan, kindly send me your personal id – i need to take your suggestions.
you can email me test mail at shahhasan86@gmail.com
waiting for your reply
regards
srinivas said
hi pavan this is srinivas from kodada, just i see ur bd (bio data)..i complted my btech(cse)in 2007 from sana engg college,kodada.after that i worked for jkc/ieg,hyderabad upto 2 yrs. i have no job satisfaction in that .. i resigned fir my duties in march-2010.i decided to mould my career in ORACLE DBA side ..i learned the things in hyderabad .. recently i came to bangalore for job trials…
I eill keep in touch with you for the improvement of myself as an ora-dba.
Pavan Kumar said
Hi Srinivas, thanks for your comments and hope to see you as great DBA in short time…. 🙂
varun said
Hello Sir,
I want to perform dataguard implementation on my laptop(both primary and standby on same system).
i googled it out…..dint got exact steps…….
plz can u send me the steps for the same.
it will be really appreciated if u mail me complete steps…
Thanks in advance
varun
Pavan Kumar said
Hi Veeru, plz look into “important docs” section of my blog which contaisn a detailed doc for the same. download it and configure DG
sai said
hi sr
you are so cool
you are very good teacher
how did u learn that much subject sr
Pavan Kumar said
Hi Sayanna,
thanks for your comments. i am trying to be best actually. subject learning is because of my passion on oracle DBA. i wann all to be like that….
raghu said
hai…raghu 4m kanna techonologies…….your so cool sir
Pavan Kumar said
thanks…still wann to be more cool… 🙂
RamaRaju said
hi, pavan this is ramaraju,up dated with u r blog last month but sorry unable to be in touch with u.thanks for u r recruitment up dates.
Pavan Kumar said
Hi Ramaraju,
Thanks for your comments….
Munna said
Hey Pavan,
Hope you are fine.
I got the answer for this…
Is there any way to list the objects that statistics are not collected and not good enough. If so what are the methods. (For a schema/for a object / for a database)
Please do not mention about last_analyzed as everybody knows about it.
Ans :
” dba_tab_statistics & dba_ind_statistics
These views have a column named STALE_STATS, which automatically gets updated to ‘YES’ for a table or index if more than 10% of its data is modified since its last update-stats.
— To know a list of objects with stale stats at the schema level,
we can call the package
DBMS_STATS.GATHER_SCHEMA_STATS with the parameter options=>’LIST STALE’
DBMS_STATS.GATHER_DATABASE_STATS with the parameter options=>’LIST STALE’
This will internally fetch its data from *_tab_modifications views
In 10g when the value of statistics_level is ‘typical’ or ‘all’ table monitoring is automatically enabled. ”
And also look at round(sample_size/num_rows*100,1) AS “%” from dba_tables which gives a percentage of collection for an object.
Pavan Kumar said
really worthy info…thanks for sharing
srikanth.M said
hi sir,
i have seen u r blog it’s great.
u r guidence is good b’cause i know without guidence its hard to survive in this competitive market(once I failed without guidence).
Let me hope this time i will get the right guidence from u to get job.Anyways u r blog is very great.
………srikanth.M
Pavan Kumar said
thanks for ur comments. surely i will guide you…dnt wrry
srikanth said
thanks for u r reply.
Munna said
Hi Pavan,
I need your help.
1. How to resovle the ORA-1555 error while exporting using exp.
2. On what basis we decide the buffer parameter in exp?
Pavan Kumar said
Hi Munna,
1. you will be getting ora-1555 in exp when using consistent=y parameter. the possible solution is to increase either undo tablespace size or undo retention size. if you are using 10g, then oracle will have automatic undo retention by which your datapump will not get these problems.
2. buffer will be decided on 10*avg row length formula for that table or schema.
you can get avg row length for a table or schema from dba_tables.
ex: if you get avg row lengthas 1284, then buffer = 10*1284.
but in general we will give some value like 50000 or 100000 to it, instead of calculating with formula.
Munna said
thank you…..pavan….
Munna said
Hey Panan,
Can i have your personal mail id please, so that i can send you some questions i have.
Or you can just send me an email to my mail id.
–Munna
Pavan Kumar said
mymailbox.21@gmail.com. had sent mail to you
Ravinder Reddy.V said
hi sir,
Its really excellent. I learnt many new things in oracle database architecture only.
Thank u for giving this formation.
Pavan Kumar said
Hi Ravinder, thank you very much…
pintu said
Hi Pavan,
I have been working as DBA for last 4 yrs (mainly as dev dba). So didn’t get chance to work on third party tools for backup and recovery. I’m interested into learning somewhat about unix administration and third party tools like TSN, veritas etc. Please let me know if you can help me with the same.
Regards,
Pintu Shah
Pavan Kumar said
Hi Pintu,
Thanks for visiting my blog !
I can’t deny learning third party tools will help you, but more than that you can explore many areas in Oracle DBA itself like RAC, ASM etc. Still even you can go for APPS DBA.
Personally i had not seen any benefit after doing unix admin etc…but yes i do accept it will give good idea.
Its just a suggestion and Rest is in your hands…. 🙂
anjibabu said
hi this is anjibabu
I completed db2 dba cetification.
iam completed b.tech in computerscience
any fresher job or db2 dba jobs we can send mail or call
Thanks & regards
anjibabu m
9611445878
anjicse88@gmail.com
Pavan Kumar said
will send u sms….to ur number
Praneeth said
Hi Pavan,
Do you take up apps dba training in your institute. Can you please provide me with the course,fee and duration details for the batch. please do specify me the recent date when u can start the batch.
Thanks,
Praneeth
Pavan Kumar said
Hi Praneeth, i mailed you the details to ur id. plz check
Babasaheb godase said
Hi sir,
i have joined one institute as a dba trainer
not main batch but handling lab demo’s and taking basic sql and unix part…
so,i’m using ur notes and those are rocking here….
Pavan Kumar said
nice to hear that….my friend also jumped into this path 🙂
I wish you All the Very BEST for your new role and want to transform into a full fledged trainer
Thanks alot…your support made me to frame that notes….
Vidya said
Hi Pavan,
This blog is fentastic and it helped me to clear most of the doubts.thanks for guiding us.
Vidya
Pavan Kumar said
thnx fr ur comments…and still am striking hard to learn n post new things in oracle
Munna said
Hey Pavan(Father Of Oracle),
First of all I wanna appriciate for sharing your knowledge.I feel very happy and gianing good knowledge by going through your blog.
Your parents are very lucky…blessed with a son like you.
Keep posting the new updates.
–Munna 🙂
Pavan Kumar said
Hi Munna,
I can never be a father of oracle. there are lot many people for that designation. i just know 1% of DBA and still waiting to learn more and more and working hard for that.
and a small correction in your statement (if don’t mind). anytime i am lucky to be a son to my parents who strive hard for me all these years.
with all your co-operation and blessings i will continue to post new updates all the time….
Once again thanks for commenting…. 🙂
Bhaskar ME said
Dear Pavan,
You are doing a wonderful job. I was sitting next to you in all the days of our college, but only now i am coming to know about your talents.
I need more oracle developers in my team. Will let you know more details in personal email.
ALL THE BEST.
Thanks, Bhaskar ME
Pavan Kumar said
yes macha…at that time i am a buddy and now slowly trying to turn to flower….. 🙂
Babasaheb said
hi…pavan sir, this is babasaheb from pune…
ur blog is very nice….
i start my day with ur blog…
plz send me updates…preparing for ocp
really u r rocking…………..
Pavan Kumar said
hi, nice to hear from you after long time….thanks for your valuable comments. i hope you already doing hands-on practise. it will be enough for OCP.
Krishnakant said
Hi Pavan!
Nice to see your blog! and also was looking into the comments from the other people. All the best dude….
Give me your mobile. Will call you…
Regards,
Krishnakant
Pavan Kumar said
thank you very much…
pawan.v(BNG) said
Hi Pavan,
Good. Keep going on…..
Thanks & Regards,
Pawan.V
Bengaluru.
Pavan Kumar said
thank you very much
phaniRam said
its really good, it will be supportive for junior DBA’s
Rakesh Soni said
I am really glad to see that you have become EXPERT in the field of Oracle Databases… great. 🙂
Please teach me Oracle Databases too, I am Rakesh Soni from Karachi, Pakistan.
Regards
Pavan Kumar said
Hi Rakesh, am not expert in oracle DB. i just got expert status in forums and that too i am still surprised how i got that status. So, i am not certainly in level of teaching and i can share the min knowledge through my blog. Thanks for your kind words….
Samyak Jain said
Hi Pavan , really nice blog …thanx for ur efforts
Rafi(Oracle DBA) said
Hi Pavan,
This Blog is really excellent……….No words………No comments…….
Thanks,
Rafi
Pavan Kumar said
thanks Rafi
Aman.... said
Hey is it the same Pavan from oracle forums? If yes, teach some thing about Oracle to me also dude and if you are in Hyderabad,spend some busy time to meet me 😉 .
Aman….
Pavan Kumar said
Hi Aman Sir, good to see ur comment on my blog.
yes, i am there in Oracle Forums. but as “Pavan-a DBA”. you can see one more Pavan Kumar in forums…..
Pavan Kumar N said
Hi Pavan,
I hope that one more “Pavan Kumar N” is me….;-)
Nice blog…..!!
Pavan Kumar said
hello sir, first of all thank you for your comments. I have been fond of you since our meeting in oracle forums. Hope i can add your mail id to my gmail, if you accept !
Pavan Kumar N said
Hi Pavan,
You are an Expert and I stand no-where when compared to you. I am not capable enough to standby on your side as friend… Yep, I will add up to your list, Once I am enough to something… !!
😉
All the best for your future success and I hope to learn something from you.. !!
take care..
Pavan Kumar said
always great people say this. I am really surprised to see how you can be so humble. I am just Expert, but you are Guru !!! Thanks for accepting and i will add your id to my gmail. But don’t worry i will not ping you for asking doubts. Nice to meet you again Sir !
gowtham said
hi pavan,
I am gowtham…I read ur blog for the first time and i got a little hope about my career…as i am in the same position of yours(in 2004-2005).I am a 2008 passed out and still in search of a job…I have completed courses in oracle dba and peoplesoft dba.As you are working on oracle can you help me out in anyway with my career…I will thankful to you if you can guide me….
regards,
gowtham,
gowtham.pathakamuri@gmail.com
Pavan Kumar said
hi gowtham, surely i will charge you up. please let me knw in wht way i can help you?
Satish said
Hi Pavan,
Nice blog.
All the dba posts are very much useful.
KEEP POSTING
Thanks and Regards,
Satish.G.S
kishore said
fixed size means
A portion of the SGA contains general information about the state of the database and the instance, which the background processes need to access; this is called the Fixed SGA. No user data is stored here. The SGA also includes information communicated between processes, such as locking information
kishore said
happy pongal sir to u n ur parents
Pavan Kumar said
thank you and wish you the same
kishore said
hi sir
ur blog is nice, its very helpful for us. i read ur profile its good. i like that u dedicated this blog to ur parents. say namasate to ur parents.
Pavan Kumar said
thank you
jagat mohanty said
I was the 1st student of Pavan who got placed as a DBA in one of the world’s largest MNC within no time.
This guy having loads of talents.
Pavan Kumar said
yes. forever i am proud of that 🙂
but as a fact, at that time, i could not able to spend much time for you people. Its all your hardwork and passion towards DBA which made this possible !
Sagar said
Hi Pavan,
Your profile is simply super like your smile.
The ways you are presenting DBA Class are extraordinary.
Sagar
9603182181
Pavan Kumar said
thank you very much Sagar !
Sateesh Kumar.P (DBA) said
Hi Sir,
Your Blog is very nice, and the colors u choosen is also nice.
I read your “About Me” , it is good, but you forgot your school name (T.K.S.V) that’s not good, re-collect your school name, and post it also.
Satishp.
Pavan Kumar said
sure i will recollect and will update it
SUNIL SURYADEVARA said
Change the caption as
“DBA KNOWLEDGE FACTORY” like RGV-FACTORY ———————————–
Pavan Kumar said
thanks for the caption, but i dnt wann to copy anybody
SUNIL SURYADEVARA said
Hi Pavan,
Good to see your blog.I had looked into some of the posts uploaded by you.They are very useful & nice.What a person you are,thank you for your kindness.Being in a position, and sharing all the knowledge with others ,with latest updates.
According to my experience and thinking one should not be a egoist or proud regarding subject or knowledge irrespective of their age and position.We should share with one another,so that they would also be upto the levels.
Hope all of our group people & friends would be benefited with this blog.
Bang on! & go ahead
SUNIL SURYADEVARA