Alexander Okulovich <aokulovich@xxxxxxxxxxxxx> writes: > We used the product with the default settings. The requests are simple. > We didn't change the hardware (actually, we use even more performant > hardware because of that issue) and DDL. I've checked the request on old > and new databases. Requests that rely on this index execute more than 10 > times longer. Planner indeed used Index Scan before, but now it doesn't. > So, from my perspective, the only reason we experience that is database > logic change. [ shrug... ] Maybe, but it's still not clear if it's a bug, or an intentional change, or just a cost estimate that was on the hairy edge before and your luck ran out. If you could provide a self-contained test case that performs 10x worse under v15 than v12, we'd surely take a look at it. But with the information you've given so far, little is possible beyond speculation. regards, tom lane
