Hi,
On 20 September 2012 20:49, AI Rumman <rummandba@gmail.com> wrote:
> Using explain analyze of a large query I found that in every step there are
> a lot difference between the number of rows between actual and estimated.
> I am using default_statistics_target 200. Should I increase it?
I would keep it at default level but I would increase it per column:
ALTER TABLE <table> ALTER <column> SET STATISTICS <number>
and you can do the same for index:
ALTER TABLE <index_name> ALTER COLUMN <column> SET STATISTICS <number>
(for function indexes you need to use \d in order to see "real" column name)
Finally, you need to run analyse on that table / column
--
Ondrej Ivanic
(ondrej.ivanic@gmail.com)