Tom Lane-2 wrote
> In the meantime, I assume that your real data contains a small percentage
> of values other than these two?  If so, maybe cranking up the statistics
> target would help.  If the planner knows that there are more than two
> values in the column, I think it would be less optimistic about assuming
> that the comparison value is one of the big two.

Is there any value (or can value be added) in creating a partial index of
the form:

archetype IN ('banner','some other rare value')

such that the planner will see that such a value is possible but infrequent
and will, in the presence of a plan using a value contained in the partial
index, refuse to use a generic plan knowing that it will be unable to use
the very specific index that the user created?

David J.





--
View this message in context: 
http://postgresql.nabble.com/Re-GENERAL-Performance-issue-with-libpq-prepared-queries-on-9-3-and-9-4-tp5826919p5826921.html
Sent from the PostgreSQL - hackers mailing list archive at Nabble.com.


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

Reply via email to