Re: psql's FETCH_COUNT (cursor) is not being respected for CTEs

Alexander Law <exclusion@gmail.com>

From: Alexander Lakhin <exclusion@gmail.com>

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

Cc: Daniel Verite <daniel@manitou-mail.org>, Laurenz Albe <laurenz.albe@cybertec.at>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Jakub Wartak <jakub.wartak@enterprisedb.com>

Date: 2024-04-08T15:15:15Z

Lists: pgsql-hackers

08.04.2024 18:08, Tom Lane wrote:
> Alexander Lakhin <exclusion@gmail.com> writes:
>> Now that ExecQueryUsingCursor() is gone, it's not clear, what does
>> the following comment mean:?
>>      * We must turn off gexec_flag to avoid infinite recursion.  Note that
>>      * this allows ExecQueryUsingCursor to be applied to the individual query
>>      * results.
> Hmm, the point about recursion is still valid isn't it?  I agree the
> reference to ExecQueryUsingCursor is obsolete, but I think we need to
> reconstruct what this comment is actually talking about.  It's
> certainly pretty obscure ...

Sorry, I wasn't clear enough, I meant to remove only that reference, not
the quoted comment altogether.

Best regards,
Alexander

Commits

Further review for re-implementation of psql's FETCH_COUNT feature.
- c21d4c416ad6 17.0 landed
Re-implement psql's FETCH_COUNT feature atop libpq's chunked mode.
- 90f5178211cd 17.0 landed
Support retrieval of results in chunks with libpq.
- 4643a2b265e9 17.0 landed
Attempt to fix newly added Memoize regression test
- a3a836fb5e51 17.0 cited