Horton

Re: Retrieving query results

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Igor Korot <ikorot01@gmail.com>
Cc: Michael Paquier <michael.paquier@gmail.com>, pgsql-general <pgsql-general@postgresql.org>
Date: 2017-08-24T23:18:47Z
Lists: pgsql-general 
Igor Korot <ikorot01@gmail.com> writes:
> So there is no way to retrieve an arbitrary number of rows from the query?
> That sucks...

The restriction is on the number of rows in one PGresult, not the total
size of the query result.  You could use single-row mode, or use a cursor
and fetch some reasonable number of rows at a time.  If you try to inhale
all of a many-gigarow result at once, you're going to have OOM problems
anyway, even if you had the patience to wait for it.  So I don't think the
existence of a limit is a problem.  Failure to check it *is* a problem,
certainly.

			regards, tom lane

Commits

  1. Doc: document libpq's restriction to INT_MAX rows in a PGresult.

  2. Teach libpq to detect integer overflow in the row count of a PGresult.