Re: meaning of default_statistics_target

Martin Marques <martin(at)marquesminen(dot)com(dot)ar> writes:
> How much, and which extra statistics information will ANALYZE gather if
> I set a higher value for one specific column (maybe one with and index,
> and heavily used in SELECT clauses)? If instead of 100 I set a column to
> 250, which extra data will I see in pg_statistics after an ANALYZE?

The target determines the desired size of the histogram and
most-common-values arrays. Increasing it gives you better resolution of
those stats.

Increasing the target also increases the number of rows that ANALYZE
samples to prepare the stats, so you should theoretically get more
accurate stats for the other columns too, even though they'll still get
boiled down to the same array lengths as before.

regards, tom lane