Re: tsvector pg_stats seems quite a bit off.
Jesper Krogh <jesper@krogh.cc>
From: Jesper Krogh <jesper@krogh.cc>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Jan Urbański <wulczer@wulczer.org>, pgsql-hackers@postgresql.org
Date: 2010-06-01T04:50:45Z
Lists: pgsql-hackers
On 2010-05-31 20:38, Tom Lane wrote: > Jesper Krogh<jesper@krogh.cc> writes: > >> Just a small follow up. I tried out the patch (or actually a fresh git >> checkout) and it now gives very accurate results for both upper and >> lower end of the MCE-histogram with a lower cutoff that doesn't >> approach 2. >> > Good. How much did the ANALYZE time change for your table? > 1.3m documents. New code ( 3 runs): statistics target 1000 => 155s/124s/110s statictics target 100 => 86s/55s/61s Old code: statistics target 1000 => 158s/101s/99s statistics target 100 => 90s/29s/33s Somehow I think that the first run is the relevant one, its pretty much a "dead disk" test, and I wouldn't expect that random sampling of tuples would have any sane caching effect in a production system. But it looks like the algoritm is "a bit" slower. Thanks again.. Jesper -- Jesper