On 7 May 2014 17:43, Stephen Frost <sfr...@snowman.net> wrote: > * Simon Riggs (si...@2ndquadrant.com) wrote: >> IMHO we would not want to add indexes to every column, on every table, >> nor would we wish to use lookaside for all tables. It is a good thing >> to be able to add optimizations for individual tables. GPUs are not >> good for everything; it is good to be able to leverage their >> strengths, yet avoid their weaknesses. > > It's the optimizer's job to figure out which path to pick though, based > on which will have the lowest cost.
Of course. I'm not suggesting otherwise. >> If do you want that, you can write an Event Trigger that automatically >> adds a lookaside for any table. > > This sounds terribly ugly and like we're pushing optimization decisions > on to the user instead of just figuring out what the best answer is. I'm proposing that we use a declarative approach, just like we do when we say CREATE INDEX. The idea is that we only consider a lookaside when a lookaside has been declared. Same as when we add an index, the optimizer considers whether to use that index. What we don't want to happen is that the optimizer considers a GIN plan, even when a GIN index is not available. I'll explain it more at the developer meeting. It probably sounds a bit weird at first. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
