On Wed, Feb 29, 2012 at 5:43 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Nathan Boley <npbo...@gmail.com> writes: >> On Wed, Feb 29, 2012 at 12:39 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: >>> I am starting to look at this patch now. I'm wondering exactly why the >>> decision was made to continue storing btree-style statistics for arrays, >>> in addition to the new stuff. > >> If I understand you're suggestion, queries of the form > >> SELECT * FROM rel >> WHERE ARRAY[ 1,2,3,4 ] <= x >> AND x <=ARRAY[ 1, 2, 3, 1000]; > >> would no longer use an index. Is that correct? > > No, just that we'd no longer have statistics relevant to that, and would > have to fall back on default selectivity assumptions. Do you think that > such applications are so common as to justify bloating pg_statistic for > everybody that uses arrays?
I confess I am nervous about ripping this out. I am pretty sure we will get complaints about it. Performance optimizations that benefit group A at the expense of group B are always iffy, and I'm not sure the case of using an array as a path indicator is as uncommon as you seem to think. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
