Josh Berkus <josh@xxxxxxxxxxxx> writes: > Here's a case which it seems like we ought to be able to optimize for: > [ offset skips all the output of a sort node ] > Is there some non-obvious reason which would make this kind of > optimization difficult? Doesn't the executor know at that point how > many rows it has? In principle, yeah, we could make it do that, but it seems like a likely source of maintenance headaches. This example is not exactly compelling enough to make me want to do it. Large OFFSETs are always going to be problematic from a performance standpoint, and the fact that we could short-circuit this one corner case isn't really going to make them much more usable. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
