On Mon, Dec 7, 2009 at 7:01 AM, Sam Mason <s...@samason.me.uk> wrote: > On Sat, Dec 05, 2009 at 09:54:58AM -0500, Merlin Moncure wrote: >> GIN is a pretty heavy price to pay for something that should be btree >> indexable. Also note he is using a multi column index with array as >> second column...that would be pretty awkward with GIN. > > Yup, sounds as though it's not going to work here. I was mainly > suggesting it as it's working now, as opposed to something that > could/should be made to work. > >> Normalizing the data loses the nice property of being able to order >> the entire structure using a single index. He's using the array as if >> it was a string...it's basically an optimization. > > Hum, not sure why this didn't come up already: what about having an > index on (type,(array_to_string(ident,'##')) and relying on the already > existing optimizations for string prefixes. Not sure what sort of > values can be used in "ident", but it could work.
hm, that's certainly an interesting idea, but I think unless you pad all the strings out you are going to run into some odd ordering issues. If it works though I think you'll have a much tighter index than the raw one over the array. merlin -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
