Andres Freund <[email protected]> writes:
> On November 30, 2022 3:47:32 AM PST, Andrew Dunstan <[email protected]>
> wrote:
>> I think Alvaro's point is that it would have been better to work out
>> these wrinkles before turning on JIT by default. Based on anecdotal
>> reports from the field I'm inclined to agree.
> The problem is that back when it was introduced these problems didn't exist
> to a significant degree. JIT was developed when partitioning was very
> minimal- and the problems we're seeing are almost exclusively with queries
> with many partitions. The problems really only started much more recently. It
> also wasn't enabled in the first release..
Well, wherever you want to pin the blame, it seems clear that we
have a problem now. And I don't think flipping back to off-by-default
is the answer -- surely there is some population of users who will
not be happy with that. We really need to prioritize fixing the
cost-estimation problems, and/or tweaking the default thresholds.
regards, tom lane
