Bruce Momjian <br...@momjian.us> writes: > Tom Lane wrote: >> You seem to be confusing one limitation in one code path with the >> overall meaning of maintenance_work_mem.
> Oh, OK, so sorts are limited, but not hash sizes? Are there any other > uses? Should this be documented somehow? What is the actual sort > limit? The particular complaint that's being made here is about tuplesort.c's array of SortTuples, which isn't all (or even the largest part) of its memory consumption. The tuples themselves eat significantly more in nearly all cases. I don't think there's any very easy way to document what the largest useful maintenance_work_mem for sorting is based on that --- you'd have to pull a number for tuple size out of the air. But it's certainly possible to use up lots of gigabytes when sorting wide tuples. I think the original complaint in this thread was about building an index, which probably had relatively small tuples so the SortTuple constraint was more pressing. In any case, this is the sort of thing that'd be far better to fix than document. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers