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vacuum locking

From: Rob Nagler <nagler(at)bivio(dot)biz>
To: pgsql-performance(at)postgresql(dot)org
Subject: vacuum locking
Date: 2003-10-17 14:48:30
Message-ID: 16272.318.870000.93584@gargle.gargle.HOWL (view raw or flat)
Thread:
Lists: pgsql-performance
It seems a simple "vacuum" (not full or analyze) slows down the
database dramatically.  I am running vacuum every 15 minutes, but it
takes about 5 minutes to run even after a fresh import.  Even with
vacuuming every 15 minutes, I'm not sure vacuuming is working
properly.

There are a lot of updates.  The slowest relation is the primary key
index, which is composed of a sequence.  I've appended a csv with the
parsed output from vacuum.  The page counts are growing way too fast
imo.  I believe this is caused by the updates, and index pages not
getting re-used.  The index values aren't changing, but other values
in the table are.

Any suggestions how to make vacuuming more effective and reducing the
time it takes to vacuum?  I'd settle for less frequent vacuuming or
perhaps index rebuilding.  The database can be re-imported in about an
hour.

Rob
----------------------------------------------------------------
Spacing every 15 minutes
Pages,Tuples,Deleted
7974,1029258,1536
7979,1025951,4336
7979,1026129,52
7979,1025618,686
7979,1025520,152
7980,1025583,28
7995,1028008,6
8004,1030016,14
8010,1026149,4965
8012,1026684,6
8014,1025910,960
8020,1026812,114
8027,1027642,50
8031,1027913,362
8040,1028368,784
8046,1028454,1143
8049,1029155,6
8053,1029980,10
8065,1031506,24
8084,1029134,4804
8098,1031004,346
8103,1029412,3044
8118,1029736,1872
8141,1031643,1704
8150,1032597,286
8152,1033222,6
8159,1029436,4845
8165,1029987,712
8170,1030229,268
8176,1029568,1632
8189,1030136,1540
8218,1030915,3963
8255,1033049,4598
8297,1036583,3866
8308,1031412,8640
8315,1031987,1058
8325,1033892,6
8334,1030589,4625
8350,1031709,1040
8400,1033071,5946
8426,1031555,8368
8434,1031638,2240
8436,1031703,872
8442,1031891,612



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Next:From: Shridhar DaithankarDate: 2003-10-17 15:11:59
Subject: Re: vacuum locking
Previous:From: Murthy KambhampatyDate: 2003-10-17 14:45:37
Subject: Re: [PERFORM] backup/restore - another area.

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