pg.ddx.io pgsql-performance@postgresql.org mailing list archive help / color / mirror / Atom feed From: David Gagnon <dgagnon@siunik.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Bricklen Anderson <BAnderson@PresiNET.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Please help with this explain analyse...
Date: Mon, 28 Nov 2005 21:16:52 -0500
Message-ID: <438BBA14.5080103@siunik.com> (raw )
In-Reply-To: <17298.1133222430@sss.pgh.pa.us >
References: <438B958B.3010602@siunik.com >
<438B96C6.4090902@PresiNET.com >
<17298.1133222430@sss.pgh.pa.us >
I restored my db but haven't run the analyse... That was the problem.
Thanks
/David
"Merge Left Join (cost=2273.54..2290.19 rows=228 width=816) (actual
time=2098.257..2444.472 rows=8335 loops=1)"
" Merge Cond: (("outer".rrnum)::text = "inner"."?column8?")"
" -> Merge Join (cost=2131.25..2141.31 rows=228 width=744) (actual
time=2037.953..2251.289 rows=8335 loops=1)"
" Merge Cond: ("outer"."?column31?" = "inner"."?column77?")"
" -> Sort (cost=1975.03..1975.60 rows=228 width=235) (actual
time=1798.556..1811.828 rows=8335 loops=1)"
" Sort Key: (cr.crrrnum)::text"
" -> Hash Join (cost=1451.41..1966.10 rows=228 width=235)
(actual time=267.751..515.396 rows=8335 loops=1)"
" Hash Cond: ("outer".crnum = "inner".cscrnum)"
" -> Seq Scan on cr (cost=0.00..489.77 rows=4529
width=101) (actual time=0.077..97.615 rows=8335 loops=1)"
" Filter: (((crypnum)::text = 'M'::text) AND
((crdate + '00:00:00'::interval) <= '2005-01-28 00:00:00'::timestamp
without time zone))"
" -> Hash (cost=1449.70..1449.70 rows=684
width=134) (actual time=267.568..267.568 rows=13587 loops=1)"
" -> Nested Loop (cost=20.59..1449.70
rows=684 width=134) (actual time=33.099..178.524 rows=13587 loops=1)"
" -> Seq Scan on gl (cost=0.00..5.21
rows=2 width=91) (actual time=0.021..0.357 rows=1 loops=1)"
" Filter: (glsoctrl = 1)"
" -> Bitmap Heap Scan on cs
(cost=20.59..684.42 rows=3026 width=43) (actual time=33.047..115.151
rows=13587 loops=1)"
" Recheck Cond: ((cs.csglnum)::text
= ("outer".glnum)::text)"
" Filter: ('M'::text =
(csypnum)::text)"
" -> Bitmap Index Scan on
cs_gl_fk (cost=0.00..20.59 rows=3026 width=0) (actual
time=32.475..32.475 rows=13587 loops=1)"
" Index Cond:
((cs.csglnum)::text = ("outer".glnum)::text)"
" -> Sort (cost=156.22..159.65 rows=1372 width=509) (actual
time=239.315..254.024 rows=8974 loops=1)"
" Sort Key: (rr.rrnum)::text"
" -> Seq Scan on rr (cost=0.00..84.72 rows=1372
width=509) (actual time=0.055..33.564 rows=1372 loops=1)"
" -> Sort (cost=142.29..144.55 rows=903 width=72) (actual
time=60.246..74.813 rows=8932 loops=1)"
" Sort Key: (yr.yrref)::text"
" -> Bitmap Heap Scan on yr (cost=16.42..97.96 rows=903
width=72) (actual time=8.513..13.587 rows=1154 loops=1)"
" Recheck Cond: (((yryotype)::text = 'Client'::text) AND
((yryonum)::text = 'Comptabilite.Recevable.Regroupement'::text))"
" -> Bitmap Index Scan on yr_idx1 (cost=0.00..16.42
rows=903 width=0) (actual time=8.471..8.471 rows=1154 loops=1)"
" Index Cond: (((yryotype)::text = 'Client'::text)
AND ((yryonum)::text = 'Comptabilite.Recevable.Regroupement'::text))"
"Total runtime: 2466.197 ms"
>Bricklen Anderson <BAnderson@PresiNET.com> writes:
>
>
>>Your loops are what is causing the time spent.
>>eg. "actual time=0.127..17.379 rows=1154 loops=8335)" ==
>>8335*(17.379-0.127)/1000=>143 secs (if my math is correct).
>>
>>
>
>As for where the problem is, I think it's the horrid misestimate of the
>number of matching rows in cs_pk:
>
>
>
>>>" -> Index Scan using cs_pk on cs (cost=0.00..12.83
>>>rows=2 width=144) (actual time=0.087..444.999 rows=13587 loops=1)"
>>>" Index Cond: (('M'::text = (cs.csypnum)::text)
>>>AND ((cs.csglnum)::text = ("outer".glnum)::text))"
>>>
>>>
>
>Has that table been ANALYZEd recently? How about the gl table?
>
> regards, tom lane
>
>
>
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To: pgsql-performance@postgresql.org
Cc: dgagnon@siunik.com, tgl@sss.pgh.pa.us, BAnderson@PresiNET.com
Subject: Re: Please help with this explain analyse...
In-Reply-To: <438BBA14.5080103@siunik.com>
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