Hi all.
I have a query which takes forever and the only way I've been able to make it
perform reasonably well is increasing join_collapse_limit to 14 (12 still
produced lots of nest-loops).
This way lots of nest-loops (which I think caused the slowness) was made into
hash-joins and performance was acceptable again.
I wonder; In general, is there any downside of having join_collapse_limit = 14
on modern hardware (32 cores, 64GB RAM), and geqo_threshold=16 ?
I'm aware of it increasing planning-time, but is this really an issue in
practice?
Thanks.
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