On 11/12/24 21:37, Tom Lane wrote:
Achilleas Mantzios <a.mantzios@xxxxxxxxxxxxxxxxxxxx> writes:
Our sysadm created the system debian Debian GNU/Linux 12 (bookworm)with
postgres as user 1000. Now at some point we realized that whenever we
run a pgsql cluster with another user (I found that after spending two
good days testing), the above query runs in about 1 second. With user
postgres 1000 in 30 seconds. As you saw the perf output are completely
different.
Don't recall details offhand, but in some situations where the calling
SQL user doesn't have permissions to read particular columns, the
planner will not consult statistics for those columns. That can lead
to a different, less optimal plan being used. Maybe something like
that is happening here?
Thank you Tom,
In all runs of this query the user is postgres (superuser). Besides,
this is just a simple query run on a FOREIGN TABLE living in a MS SQL
Server.
regards, tom lane
