Laurent Manchon wrote:
> Hi,
>
> I have a slow response of my PostgreSQL database 7.4 using this query below
> on a table with 800000 rows:
>
> select count(*)from tbl;
>
> PostgreSQL return result in 28 sec every time.
Can you post the results of:
analyze verbose tbl;
explain analyze select count(*) from tbl;
The first will give us some info about how many pages tbl has (in 7.4
ISTR it does not state the # of dead rows... but anyway), the second
should help us deduce why it is so slow.
Also as others have pointed out, later versions are quite a bit faster
for sequential scans...
Cheers
Mark
