Ken Tanzer <ken.tanzer@xxxxxxxxx> writes: > Hi. I was recently troubleshooting a function, and realized it had > incorrectly been declared as Immutable, when it should have been declared > Stable. When I changed it to Stable, the query I was running ran > dramatically faster. Digging into this a little more, this is what I found: EXPLAIN VERBOSE might shed a bit more light. I suspect you're falling foul of the rather arcane rules about whether a SQL function can be inlined. (Although it seems like only the wrapper function would be inline-able anyway, so I'm not sure why the penalty is that high.) regards, tom lane
