"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. -- greg
