Re: won't drop the view
| От | Oleg Lebedev |
|---|---|
| Тема | Re: won't drop the view |
| Дата | |
| Msg-id | 3C293ACB.4BEBA02F@waterford.org обсуждение исходный текст |
| Ответ на | Re: won't drop the view ("Josh Berkus" <josh@agliodbs.com>) |
| Ответы |
Re: won't drop the view
(Tom Lane <tgl@sss.pgh.pa.us>)
|
| Список | pgsql-sql |
Thanks everybody for your help. Deleting from pg_statistic restored view performance to the way it was before I ran vacuum analyze. Below I attach two files that contain explain statistics for the view before (progress_report.txt) and after (progress_report_analyzed.txt) I ran vacuum analyze. The first one takes about 15 secs. to complete, the second one takes 12-13 minutes to complete. I hope this will help you improve your query optimizer. thanks, Oleg Tom Lane wrote: > "Josh Berkus" <josh@agliodbs.com> writes: > > Damn. I can only really help with the obvious things, and you've > > covered most of those. That view should take a long time, given the > > complexity ... but a long time is 30-60 seconds, not 10 minutes. > > I'm guessing it's ye olde stupid-choice-of-plan kind of problem. > Unless I missed it, we have not been shown the plan currently being > used (no, the first four lines don't do it for me...) > > You could probably get back to the previous, not-so-slow plan choice > by doing "DELETE FROM pg_statistic" to remove the data collected by > VACUUM ANALYZE. A comparison of the EXPLAIN output in that state > vs. the EXPLAIN output in the analyzed state might be enlightening. > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/users-lounge/docs/faq.html execution time ~ 15sec. NOTICE: QUERY PLAN: Subquery Scan progress_report (cost=14648.65..14648.65 rows=4 width=128) -> Sort (cost=14648.65..14648.65 rows=4 width=128) -> Merge Join (cost=14644.00..14648.62 rows=4 width=128) -> Sort (cost=11.02..11.02 rows=2 width=48) -> Seq Scan on activity (cost=0.00..11.00 rows=2 width=48) -> Sort (cost=14632.99..14632.99 rows=367 width=112) -> Subquery Scan media_acts (cost=14553.17..14617.36 rows=367 width=112) -> Aggregate (cost=14553.17..14617.36 rows=367 width=112) -> Group (cost=14553.17..14562.34 rows=3668 width=112) -> Sort (cost=14553.17..14553.17 rows=3668 width=112) -> Subquery Scan stats (cost=13969.18..14336.00 rows=3668 width=112) -> Unique (cost=13969.18..14336.00 rows=3668 width=112) -> Sort (cost=13969.18..13969.18 rows=36682 width=112) -> Append (cost=1.31..9744.33 rows=36682 width=112) -> Subquery Scan *SELECT* 1 (cost=1.31..1154.05 rows=11459width=56) -> Hash Join (cost=1.31..1154.05 rows=11459 width=56) -> Seq Scan on media (cost=0.00..407.59rows=11459 width=36) -> Hash (cost=1.25..1.25 rows=25 width=20) -> Seq Scan on mediatypemap (cost=0.00..1.25rows=25 width=20) -> Subquery Scan *SELECT* 2 (cost=1313.31..4930.60rows=20704 width=80) -> Hash Join (cost=1313.31..4930.60 rows=20704width=80) -> Hash Join (cost=1283.70..3513.64 rows=21196width=64) -> Seq Scan on intsetmedia (cost=0.00..399.96rows=21196 width=16) -> Hash (cost=1154.05..1154.05 rows=11459width=48) -> Hash Join (cost=1.31..1154.05rows=11459 width=48) -> Seq Scan on media (cost=0.00..407.59 rows=11459 width=28) -> Hash (cost=1.25..1.25rows=25 width=20) -> Seq Scan on mediatypemap (cost=0.00..1.25 rows=25 width=20) -> Hash (cost=27.69..27.69 rows=769 width=16) -> Seq Scan on set (cost=0.00..27.69rows=769 width=16) -> Subquery Scan *SELECT* 3 (cost=1469.06..3659.68rows=4519 width=112) -> Hash Join (cost=1469.06..3659.68 rows=4519width=112) -> Hash Join (cost=1467.74..3364.32 rows=4519width=92) -> Hash Join (cost=689.81..1978.41rows=4519 width=64) -> Hash Join (cost=585.40..1498.78rows=9148 width=32) -> Seq Scan on dtrowmedia (cost=0.00..164.48 rows=9148 width=16) -> Hash (cost=306.99..306.99rows=16799 width=16) -> Seq Scan on dtrow (cost=0.00..306.99 rows=16799 width=16) -> Hash (cost=102.55..102.55rows=744 width=32) -> Hash Join (cost=6.62..102.55rows=744 width=32) -> Seq Scan on dtcol (cost=0.00..32.06 rows=1506 width=16) -> Hash (cost=5.90..5.90rows=290 width=16) -> Seq Scanon datatable (cost=0.00..5.90 rows=290 width=16) -> Hash (cost=407.59..407.59 rows=11459width=28) -> Seq Scan on media (cost=0.00..407.59rows=11459 width=28) -> Hash (cost=1.25..1.25 rows=25 width=20) -> Seq Scan on mediatypemap (cost=0.00..1.25rows=25 width=20) EXPLAIN execution time ~ 12-13 mins. NOTICE: QUERY PLAN: Subquery Scan progress_report (cost=14687.00..14687.00 rows=2 width=128) -> Sort (cost=14687.00..14687.00 rows=2 width=128) -> Nested Loop (cost=14605.17..14686.99 rows=2 width=128) -> Seq Scan on activity (cost=0.00..11.00 rows=1 width=48) -> Subquery Scan media_acts (cost=14605.17..14671.27 rows=378 width=112) -> Aggregate (cost=14605.17..14671.27 rows=378 width=112) -> Group (cost=14605.17..14614.61 rows=3777 width=112) -> Sort (cost=14605.17..14605.17 rows=3777 width=112) -> Subquery Scan stats (cost=14003.05..14380.75 rows=3777 width=112) -> Unique (cost=14003.05..14380.75 rows=3777 width=112) -> Sort (cost=14003.05..14003.05 rows=37771 width=112) -> Append (cost=1.31..9627.85 rows=37771 width=112) -> Subquery Scan *SELECT* 1 (cost=1.31..1154.05 rows=11459width=56) -> Hash Join (cost=1.31..1154.05 rows=11459 width=56) -> Seq Scan on media (cost=0.00..407.59 rows=11459width=36) -> Hash (cost=1.25..1.25 rows=25 width=20) -> Seq Scan on mediatypemap (cost=0.00..1.25rows=25 width=20) -> Subquery Scan *SELECT* 2 (cost=1313.31..4930.60 rows=21196width=80) -> Hash Join (cost=1313.31..4930.60 rows=21196 width=80) -> Hash Join (cost=1283.70..3513.64 rows=21196width=64) -> Seq Scan on intsetmedia (cost=0.00..399.96rows=21196 width=16) -> Hash (cost=1154.05..1154.05 rows=11459width=48) -> Hash Join (cost=1.31..1154.05rows=11459 width=48) -> Seq Scan on media (cost=0.00..407.59rows=11459 width=28) -> Hash (cost=1.25..1.25 rows=25width=20) -> Seq Scan on mediatypemap (cost=0.00..1.25 rows=25 width=20) -> Hash (cost=27.69..27.69 rows=769 width=16) -> Seq Scan on set (cost=0.00..27.69 rows=769width=16) -> Subquery Scan *SELECT* 3 (cost=1993.99..3543.20 rows=5116width=112) -> Hash Join (cost=1993.99..3543.20 rows=5116 width=112) -> Hash Join (cost=1992.68..3209.05 rows=5116width=92) -> Seq Scan on media (cost=0.00..407.59rows=11459 width=28) -> Hash (cost=1979.89..1979.89 rows=5116width=64) -> Hash Join (cost=690.05..1979.89rows=5116 width=64) -> Hash Join (cost=585.40..1498.78rows=9148 width=32) -> Seq Scan on dtrowmedia (cost=0.00..164.48 rows=9148 width=16) -> Hash (cost=306.99..306.99rows=16799 width=16) -> Seq Scan on dtrow (cost=0.00..306.99 rows=16799 width=16) -> Hash (cost=102.55..102.55rows=842 width=32) -> Hash Join (cost=6.62..102.55rows=842 width=32) -> Seq Scan on dtcol (cost=0.00..32.06 rows=1506 width=16) -> Hash (cost=5.90..5.90rows=290 width=16) -> Seq Scanon datatable (cost=0.00..5.90 rows=290 width=16) -> Hash (cost=1.25..1.25 rows=25 width=20) -> Seq Scan on mediatypemap (cost=0.00..1.25rows=25 width=20) EXPLAIN
В списке pgsql-sql по дате отправления: