Hi Tom -
Thanks so much for getting back to me.
I didn't realise that the costs of init/sub plans would be spread across
the call sites - I had (stupidly) assumed that each call site would
include the full cost.
Having taken a couple of days to go back over the problems I was seeing,
you were absolutely right - it was all to do with multiple call sites -
the postgres version was just a red herring.
Thanks for your help & all the best,
Dave
On 17/10/2019 10:04, Tom Lane wrote:
David Conlin <dc345@xxxxxxxxxx> writes:
Does anyone know if there's been a change in the way values for CTEs are
displayed in query plans?
Offhand I don't recall any such changes, nor does a cursory look
through explain.c find anything promising.
If you're concerned with a multiply-referenced CTE, one possibility
for funny results is that the blame for its execution cost could be
spread across the multiple call sites. The same can happen with
initplans/subplans. But I'm just guessing; you didn't show any
concrete examples so it's hard to be definite.
regards, tom lane
