public inbox for [email protected]help / color / mirror / Atom feed
Re: explain 5+ messages / 3 participants [nested] [flat]
* Re: explain @ 2025-04-24 13:41 David Rowley <[email protected]> 0 siblings, 2 replies; 5+ messages in thread From: David Rowley @ 2025-04-24 13:41 UTC (permalink / raw) To: Marc Millas <[email protected]>; +Cc: [email protected] <[email protected]> On Fri, 25 Apr 2025 at 01:32, Marc Millas <[email protected]> wrote: > Nested Loop Left Join (cost=941400.77..966327.57 rows=3 width=653) (actual time=52655.694..62533.811 rows=346 loops=1) > Buffers: shared hit=10068265 read=396705 dirtied=1858 written=218, temp read=429687 written=115187 > I/O Timings: read=79368.246 write=11.486 > > So, the total execution time is 52655 ms ok > and the total time for i/o is...79368 ms > > how ??? The 79.3 seconds is the total time spent doing reads for all parallel workers. 52.6 seconds is the wall clock time elapsed to execute the query. David ^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: explain @ 2025-04-24 13:51 Marc Millas <[email protected]> parent: David Rowley <[email protected]> 1 sibling, 0 replies; 5+ messages in thread From: Marc Millas @ 2025-04-24 13:51 UTC (permalink / raw) To: David Rowley <[email protected]>; +Cc: [email protected] <[email protected]> Thanks ! Marc MILLAS Senior Architect +33607850334 www.mokadb.com On Thu, Apr 24, 2025 at 3:41 PM David Rowley <[email protected]> wrote: > On Fri, 25 Apr 2025 at 01:32, Marc Millas <[email protected]> wrote: > > Nested Loop Left Join (cost=941400.77..966327.57 rows=3 width=653) > (actual time=52655.694..62533.811 rows=346 loops=1) > > Buffers: shared hit=10068265 read=396705 dirtied=1858 written=218, > temp read=429687 written=115187 > > I/O Timings: read=79368.246 write=11.486 > > > > So, the total execution time is 52655 ms ok > > and the total time for i/o is...79368 ms > > > > how ??? > > The 79.3 seconds is the total time spent doing reads for all parallel > workers. 52.6 seconds is the wall clock time elapsed to execute the > query. > > David > ^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: explain @ 2025-04-24 15:06 Laurenz Albe <[email protected]> parent: David Rowley <[email protected]> 1 sibling, 1 reply; 5+ messages in thread From: Laurenz Albe @ 2025-04-24 15:06 UTC (permalink / raw) To: David Rowley <[email protected]>; Marc Millas <[email protected]>; +Cc: [email protected] <[email protected]> On Fri, 2025-04-25 at 01:41 +1200, David Rowley wrote: > On Fri, 25 Apr 2025 at 01:32, Marc Millas <[email protected]> wrote: > > Nested Loop Left Join (cost=941400.77..966327.57 rows=3 width=653) (actual time=52655.694..62533.811 rows=346 loops=1) > > Buffers: shared hit=10068265 read=396705 dirtied=1858 written=218, temp read=429687 written=115187 > > I/O Timings: read=79368.246 write=11.486 > > > > So, the total execution time is 52655 ms ok > > and the total time for i/o is...79368 ms > > > > how ??? > > The 79.3 seconds is the total time spent doing reads for all parallel > workers. 52.6 seconds is the wall clock time elapsed to execute the > query. But wouldn't it read "loops=3" or similar then? Yours, Laurenz Albe ^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: explain @ 2025-04-25 00:36 David Rowley <[email protected]> parent: Laurenz Albe <[email protected]> 0 siblings, 1 reply; 5+ messages in thread From: David Rowley @ 2025-04-25 00:36 UTC (permalink / raw) To: Laurenz Albe <[email protected]>; +Cc: Marc Millas <[email protected]>; [email protected] <[email protected]> On Fri, 25 Apr 2025 at 03:06, Laurenz Albe <[email protected]> wrote: > > On Fri, 2025-04-25 at 01:41 +1200, David Rowley wrote: > > The 79.3 seconds is the total time spent doing reads for all parallel > > workers. 52.6 seconds is the wall clock time elapsed to execute the > > query. > > But wouldn't it read "loops=3" or similar then? Only if the Nested Loop was below the Gather / Gather Merge node. David ^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: explain @ 2025-04-25 06:02 Laurenz Albe <[email protected]> parent: David Rowley <[email protected]> 0 siblings, 0 replies; 5+ messages in thread From: Laurenz Albe @ 2025-04-25 06:02 UTC (permalink / raw) To: David Rowley <[email protected]>; +Cc: Marc Millas <[email protected]>; [email protected] <[email protected]> On Fri, 2025-04-25 at 12:36 +1200, David Rowley wrote: > On Fri, 25 Apr 2025 at 03:06, Laurenz Albe <[email protected]> wrote: > > On Fri, 2025-04-25 at 01:41 +1200, David Rowley wrote: > > > The 79.3 seconds is the total time spent doing reads for all parallel > > > workers. 52.6 seconds is the wall clock time elapsed to execute the > > > query. > > > > But wouldn't it read "loops=3" or similar then? > > Only if the Nested Loop was below the Gather / Gather Merge node. Ah, I see. The I/O time accrued in a different, lower, parallelized step of the execution plan. Yours, Laurenz Albe ^ permalink raw reply [nested|flat] 5+ messages in thread
end of thread, other threads:[~2025-04-25 06:02 UTC | newest] Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2025-04-24 13:41 Re: explain David Rowley <[email protected]> 2025-04-24 13:51 ` Marc Millas <[email protected]> 2025-04-24 15:06 ` Laurenz Albe <[email protected]> 2025-04-25 00:36 ` David Rowley <[email protected]> 2025-04-25 06:02 ` Laurenz Albe <[email protected]>
This inbox is served by agora; see mirroring instructions for how to clone and mirror all data and code used for this inbox