"Kevin Grittner" <[EMAIL PROTECTED]> 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


---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?

               http://www.postgresql.org/docs/faq

Reply via email to