On Tue, Mar 18, 2014 at 9:12 AM, Anastasia Lubennikova <lubennikov...@gmail.com> wrote: > Support for index-only scans for GIST index
This is a cool idea, if it can be made to work. > If the fetch() is specified by the developer, then using it, algorithm can > retrieve the data directly to output areas at this stage, without reference > to the heap. This seems to be the crux of your proposal, but it seems vague: what exactly do you mean by "retrieve the data directly to output areas"? What data are you going to retrieve and where are you going to put it? Another question to consider is: which operator classes do you anticipate that this will work for and which ones do you anticipate that it will not work for? Any operator class that lossifies that input data before storing it in the index is presumably doomed, but which ones do that, and which do not? Tom Lane previously proposed extending SP-GiST to support index-only scans. You might find that discussing worth reading, or perhaps consider it as an alternative if GiST doesn't work out: http://www.postgresql.org/message-id/10839.1323885...@sss.pgh.pa.us -- 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