Re: DO with a large amount of statements get stuck with high memory consumption

Jan Wieck <jan@wi3ck.info> writes:
> In the meantime, would it be appropriate to backpatch the double linking
> of memory context children at this time? I believe it has had plenty of
> testing in the 9.6 cycle to be sure it didn't break anything.

I'm concerned about the ABI breakage risk from changing a data structure
as fundamental as MemoryContext.  Yeah, code outside utils/mmgr probably
*shouldn't* be looking at that struct, but that doesn't mean it isn't.
In the past we've generally only taken that sort of risk when there was
no other way to fix a bug; and this patch isn't a bug fix.  While this
does help performance in some corner cases, I don't think it's enough of
an across-the-board win to justify the risk of back-patching.
        regards, tom lane