Does PG have an intermediate execution node to sort/batch index entries (heap tuple ptrs) by heap page prior to lookup? Something mssql does ...
> -----Original Message----- > From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Bruce Momjian > Sent: Monday, July 13, 2009 6:38 AM > To: Heikki Linnakangas > Cc: PostgreSQL-development > Subject: Re: [HACKERS] Index-only scans > > Heikki Linnakangas wrote: > > Even if we don't solve the visibility > > map problem, just allowing the executor to evaluate quals > that are not > > directly indexable using data from the index, would be useful. For > > example, "SELECT * FROM foo WHERE textcol LIKE '%bar%', and > you have a > > b-tree index on textcol, the planner could choose a > full-index-scan, > > apply the '%bar%' filter on the index tuples, and only fetch those > > heap tuples that match that qual. > > Interesting, I had not considered that. You are using the > index as a single-column table that can be scanned more > quickly than the heap. > > -- > Bruce Momjian <br...@momjian.us> http://momjian.us > EnterpriseDB http://enterprisedb.com > > + If your life is a hard drive, Christ can be your backup. + > > -- > Sent via pgsql-hackers mailing list > (pgsql-hackers@postgresql.org) To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-hackers > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
