Re: pg_upgrade and statistics

Bruce Momjian <bruce(at)momjian(dot)us> wrote:

> OK, good idea. Kevin, can you test this:
>
> PGOPTIONS='-c default_statistics_target=10' vacuumdb --all
> --analyze-only
>
> Is it faster? Thanks.

Well, I just did something similar in psql -- I disabled the delays
by:

set vacuum_cost_delay = 0;

I checked for any statistics overrides, and found none (if I did
this right):

cir=# select attrelid::regclass, attname, attstattarget from
pg_attribute where attstattarget > 0;
attrelid | attname | attstattarget
----------+---------+---------------
(0 rows)

I went even lower than you suggested:

set default_statistics_target = 4;

And it was much faster, but still more time than the pg_upgrade run
itself:

cir=# analyze;
ANALYZE
Time: 474319.826 ms

A little under 8 minutes.

-Kevin