Re: pg_upgrade and statistics

Bruce Momjian <bruce@momjian.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