On Tue, 1 Apr 2008, Andrew Dunstan wrote:
I don't know if this has come up before exactly, but is it possible that we could get a performance gain from building multiple indexes from a single sequential pass over the base table?
It pops up regularly, you might even have walked by a discussion of this idea with myself, Jan, and Jignesh over the weekend. Jignesh pointed out that index creation was a major drag on his PostgreSQL benchmarking operations and I've run into that myself. I have a large dataset and creating a simple index takes around 70% of the time it takes to load the data in the first place, his multiple index tables took multiples of load time to index. Considering that the bulk load isn't exactly speedy either this gives you an idea how much room for improvement there is.
The idea we were bouncing around went a step past that and considered this: if you have good statistics on a table, and you have a sample set of queries you want to execute against it, how would you use that information to plan what indexes should be created? Needing to be able to create multiple indexes at once efficiently was an implementation detail to pull that off.
-- * Greg Smith [EMAIL PROTECTED] http://www.gregsmith.com Baltimore, MD -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
