Обсуждение: ALTER TABLE .. SET STATISTICS

v9.6.9

For columns of type bytea which store image data (PDFs, JPGs, etc) would it 
speed up the ANALYZE process to SET STATISTICS = 0?

That way, default_statistics_target could be cranked higher -- giving better 
statistics for needed columns -- without polluting pg_statistics with 
unneeded data?

Thanks

-- 
Angular momentum makes the world go 'round.

On 2018-Aug-05, Ron wrote:

> For columns of type bytea which store image data (PDFs, JPGs, etc) would it
> speed up the ANALYZE process to SET STATISTICS = 0?

Yes.  I'd suggest also looking at ALTER TABLE ... SET STORAGE to avoid
having Postgres try to compress those columns, which is useless waste of
CPU cycles, since those formats already compress.

> That way, default_statistics_target could be cranked higher -- giving better
> statistics for needed columns -- without polluting pg_statistics with
> unneeded data?

Right.

With the default being 100 I don't think there's a real need to crank it
higher server-wide, but it may be useful to crank it higher for specific
columns.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Ron <ronljohnsonjr@gmail.com> writes:
> For columns of type bytea which store image data (PDFs, JPGs, etc) would it 
> speed up the ANALYZE process to SET STATISTICS = 0?

Should do, though I'm not sure how much of an effect you'd see.

            regards, tom lane