which process starts first when instance is started?
Posted by Pavan DBA on October 16, 2011
Long time back, I asked this question in my POLL and many of the DBA enthus choosed the option of SMON
But unfortunately, this is not the right answer (when considering 10g)
The first process that will be started when we start instance is PSP process. This is called PROCESS SPAWNER. This process is introduced in 10g and is responsible for creating and managing other oracle backgroung processes.
As the name specifies, this process can spawn so that you will see the process name as PSP0 in alert log file.
More about PSP0 will be followed in my next article…..
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Naresh kumar bapanapalli said
Hi Pavan sir ,
Plase clarify me which background process starts first when database started ,, i fould below list when database started .
PMON started with pid=2, OS id=44433556 — >
PSP0 started with pid=3, OS id=40304746 — >
MMAN started with pid=4, OS id=51052712
DBW0 started with pid=5, OS id=55443600
DBW1 started with pid=6, OS id=25952302
DBW2 started with pid=7, OS id=53280906
DBW3 started with pid=8, OS id=61472822
LGWR started with pid=9, OS id=56819938
CKPT started with pid=10, OS id=23330906
SMON started with pid=11, OS id=328184
RECO started with pid=12, OS id=59965540
CJQ0 started with pid=13, OS id=38928542
MMON started with pid=14, OS id=57671706
Best regards,
Naresh .
Pavan DBA said
Hi Naresh, even though alert log shows PMON as first process, in reality PSP0 is the first process which will start. it will then create and spawn other mandatory background processes. Same info can be found in oracle documentation as well.
Naresh kumar bapanapalli said
Hi Pavan sir ,
Thanks a lot for clarification .
Pavan DBA said
You are welcome
Sheetal k said
Hi pavan,
Thanks for providing such as
informations please
try to post more………..
Pavan DBA said
sure. will try my best always
Dharmendra said
nice……… dude
Pavan DBA said
thank you
How to resolve ORA-00490 error? « Pavan DBA's Blog said
[…] by Pavan Kumar on October 17, 2011 Yesterday in one post (https://pavandba.com/2011/10/16/which-process-starts-first-when-instance-is-started/) I explained about PSP0 process which is introduced in […]
Ashima said
Hi Pavan,
Thanks for such an informative article.
Pavan Kumar said
Thanks Ashima for your comments and trying to post more and more….