Re: Can we get rid of repeated queries from pg_dump?

Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> writes:
> Another pointlessly repetitive query is in getTriggers, which we run
> once per table to be dumped containing triggers. We could reduce that
> by running it in bulk for many relations at a time. I suppose it's
> normally not hurtful, but as we grow the number of partitions we allow
> it's going to become a problem.

Perhaps. In the regression database, only ~10% of the tables have
triggers, so it's likely not going to yield any measurable gain there.
But databases that make heavier use of foreign keys might see a win.

Another thing I've wondered about before is whether it could make sense
to read pg_attribute once rather than once per table. There might be
a fair amount of wasted work if the dump is selective, and in big DBs
the sheer size of that result could be a problem. But those reads are
definitely way up there on the number-of-queries scale.

regards, tom lane