Re: meaning of default_statistics_target

Tom Lane escribió:
> 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.

Is the value measured in some scale, or does it depend on something
internal? What does 1000 mean?