Re: query produces 1 GB temp file

Greg Stark <gsstark@mit.edu> writes:
> Dirk Lutzebaeck <lutzeb@aeccom.com> writes:
>> Can some please explain why the temp file is so huge? I understand
>> there are a lot of rows.

> Well that I can't explain. 22k rows of width 1361 doesn't sound so big to me
> either.

It was 700k rows to sort, not 22k.  The Unique/Limit superstructure
only demanded 22k rows out from the sort, but we still had to sort 'em
all to figure out which ones were the first 22k.

> The temporary table does need to store three copies of the records at
> a given time, but still it sounds like an awful lot.

Huh?

            regards, tom lane