Re: Excessive cpu usage on 10.2.0.3 linux 64bit
Date: Thu, 26 Jun 2008 11:59:19 +0300
Think about it.
For each record:
1) For each fk:
- calculate the value for the the referencing fk.
- search the index to see if you do not invalidate the fk by deleting the record. 2) For each index on the table:
- calculate the index value.
- get the block that contain that value, may cause 0 or more physical I/O.
- update the index tree 3) Delete the record from the block.
Multiply this by 4 M records and you get a lot of work.
Check the logical reads and I think you will see a lot of them.
Giovanni Cuccu wrote:
> What really puzzles me is that I cannot understand where the cpu is
> spent, because it's the cpu usage that slows the entire delete.
> Thanks a lot,