how to avoid deadlock on masive update with multiples delete - Mailing list pgsql-performance

From Anibal David Acosta
Subject how to avoid deadlock on masive update with multiples delete
Date
Msg-id 005701cda238$ba4d0350$2ee709f0$@devshock.com
Whole thread Raw
Responses Re: how to avoid deadlock on masive update with multiples delete
Re: how to avoid deadlock on masive update with multiples delete
List pgsql-performance

Hi,

I have a table with about 10 millions of records, this table is update and inserted very often during the day (approx. 200 per second) , in the night the activity is a lot less, so in the first seconds of a day (00:00:01) a batch process update  some columns (used like counters) of this table setting his value to 0.

 

Yesterday, the first time it occurs, I got a deadlock when other process try to delete multiple (about 10 or 20) rows of the same table.

 

I think that maybe the situation was:

 

Process A (PA) (massive update)

Process B (PB) (multiple delete)

 

PA Block record 1, update

PA Block record 2, update

PA Block record 3, update

PB Block record 4, delete

PB Block record 5, delete

PA Block record 4, waiting

PB Block record 3, waiting

 

The other situation could be that update process while blocking rows scale to block page and the try to scale to lock table while the delete process as some locked rows.

 

Any ideas how to prevent this situation?

 

Thanks!

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