| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Craig Ringer <craig(at)2ndquadrant(dot)com>, David Fetter <david(at)fetter(dot)org>, PG Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: More WITH |
| Date: | 2015-08-21 18:39:45 |
| Message-ID: | 28844.1440182385@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Tue, Aug 18, 2015 at 11:23 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> More generally, what would you hope to accomplish with such a construct
>> that wouldn't be better done by writing the cursor's underlying query
>> directly in the WITH clause?
> Maybe I'm stupid today, but it seems like the obvious use case would
> be fetching some but not all rows from the cursor?
And how many rows would that be? As I said, the proposed syntax leaves
it completely unclear how many rows get fetched or what the ending cursor
position is; but especially so if you want the answer to be something
other than "all/the end".
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Robert Haas | 2015-08-21 18:45:22 | Re: Reduce ProcArrayLock contention |
| Previous Message | Tom Lane | 2015-08-21 18:37:36 | Re: (full) Memory context dump considered harmful |