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can a blocked transaction affect the performance of one that is blocking it?
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* can a blocked transaction affect the performance of one that is blocking it?
@ 2024-12-09 18:42 Eric Schwarzenbach <[email protected]>
  2024-12-09 23:10 ` Re: can a blocked transaction affect the performance of one that is blocking it? Nikolay Samokhvalov <[email protected]>
  2024-12-10 09:22 ` Re: can a blocked transaction affect the performance of one that is blocking it? David Mullineux <[email protected]>
  0 siblings, 2 replies; 3+ messages in thread

From: Eric Schwarzenbach @ 2024-12-09 18:42 UTC (permalink / raw)
  To: [email protected] <[email protected]>

Hi,

Could one transaction (one that should be relatively simple and short) 
cause another complex, long running transaction (involving INSERTS, on a 
table the first transaction may be reading from) to take many orders of 
magnitude longer than it would normally? (short of competing for system 
resources, like CPU time etc, of course)

I don't believe my scenario involved a deadlock but I expect my short 
transaction was probably blocked by my long one. Does it make any sense 
that this could very significantly affect the performance of the 
non-blocked transaction?

Thanks,

Eric







^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: can a blocked transaction affect the performance of one that is blocking it?
  2024-12-09 18:42 can a blocked transaction affect the performance of one that is blocking it? Eric Schwarzenbach <[email protected]>
@ 2024-12-09 23:10 ` Nikolay Samokhvalov <[email protected]>
  1 sibling, 0 replies; 3+ messages in thread

From: Nikolay Samokhvalov @ 2024-12-09 23:10 UTC (permalink / raw)
  To: Eric Schwarzenbach <[email protected]>; +Cc: [email protected] <[email protected]>

On Mon, Dec 9, 2024 at 13:16 Eric Schwarzenbach <[email protected]>
wrote:

> Hi,
>
> Could one transaction (one that should be relatively simple and short)
> cause another complex, long running transaction (involving INSERTS, on a
> table the first transaction may be reading from) to take many orders of
> magnitude longer than it would normally? (short of competing for system
> resources, like CPU time etc, of course)
>
> I don't believe my scenario involved a deadlock but I expect my short
> transaction was probably blocked by my long one. Does it make any sense
> that this could very significantly affect the performance of the
> non-blocked transaction?
>
> Thanks,
>
> Eric


Have you tried wait event analysis (looking at wait_event_type, wait_event,
state, query samples from pg_stat_activity)?

>


^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: can a blocked transaction affect the performance of one that is blocking it?
  2024-12-09 18:42 can a blocked transaction affect the performance of one that is blocking it? Eric Schwarzenbach <[email protected]>
@ 2024-12-10 09:22 ` David Mullineux <[email protected]>
  1 sibling, 0 replies; 3+ messages in thread

From: David Mullineux @ 2024-12-10 09:22 UTC (permalink / raw)
  To: Eric Schwarzenbach <[email protected]>; +Cc: [email protected]

Yes.
Also, are you sure you mean deadlock ? It sounded like this is just a
simple lock conflict and not a deadlock.
The first transaction could be blocked on something else (even tho it's not
ally short and quick ).
Lock requests  are in a queue


On Mon, 9 Dec 2024, 21:16 Eric Schwarzenbach, <[email protected]>
wrote:

> Hi,
>
> Could one transaction (one that should be relatively simple and short)
> cause another complex, long running transaction (involving INSERTS, on a
> table the first transaction may be reading from) to take many orders of
> magnitude longer than it would normally? (short of competing for system
> resources, like CPU time etc, of course)
>
> I don't believe my scenario involved a deadlock but I expect my short
> transaction was probably blocked by my long one. Does it make any sense
> that this could very significantly affect the performance of the
> non-blocked transaction?
>
> Thanks,
>
> Eric
>
>
>
>
>


^ permalink  raw  reply  [nested|flat] 3+ messages in thread


end of thread, other threads:[~2024-12-10 09:22 UTC | newest]

Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
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2024-12-09 18:42 can a blocked transaction affect the performance of one that is blocking it? Eric Schwarzenbach <[email protected]>
2024-12-09 23:10 ` Nikolay Samokhvalov <[email protected]>
2024-12-10 09:22 ` David Mullineux <[email protected]>

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