Wells Oliver <wells.oliver@xxxxxxxxx> writes: > Hi: we do this kind of thing a lot, where we CREATE VIEW v AS SELECT > a.col1, b.col2 FROM a JOIN b ON a.b_id = b.id -- and then we write > downstream queries to do something like SELECT * FROM v WHERE col2 = 123. > Assuming here both a.col1 and a.col2 are indexed using BTREE. > It seems from my experience that this bogs down, that the query planner > doesn't necessarily know how to use indexes well from the joined table (b), > and it ends up scanning a lot more rows than we might think necessary. A simple test of that pattern gave me a reasonable-looking plan, so I suspect you are leaving out critical details. How about a concrete example? (pgsql-performance would likely be a better venue, btw.) regards, tom lane
