>>> On Wed, Feb 22, 2006 at 9:52 pm, in message <87irr6zq7j.fsf@xxxxxxxxxxxxxxxxx>, Greg Stark <gsstark@xxxxxxx> wrote: > "Kevin Grittner" <Kevin.Grittner@xxxxxxxxxxxx> writes: > >> There have been several times that I have run a SELECT COUNT(*) on an entire >> table on all central machines. On identical hardware, with identical data, >> and equivalent query loads, the PostgreSQL databases have responded with a >> count in 50% to 70% of the time of the commercial product, in spite of the >> fact that the commercial product does a scan of a non- clustered index while >> PostgreSQL scans the data pages. > > I take it these are fairly narrow rows? The big benefit of index- only scans > come in when you're scanning extremely wide tables, often counting rows > matching some indexed criteria. I'm not sure what you would consider "fairly narrow rows" -- so see the attached. This is the VACUUM ANALYZE VERBOSE output for the largest table, from last night's regular maintenance run. -Kevin
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CaseHist-vacuum-analyze.txt
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