| From: | Antonin Houska <antonin(dot)houska(at)gmail(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: LATERAL quals revisited |
| Date: | 2013-07-04 16:11:47 |
| Message-ID: | 51D59EC3.2020902@gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 07/03/2013 08:32 PM, Tom Lane wrote:
> Another possibility would be to keep the optimization, but disable it in
> queries that use LATERAL. I don't much care for that though --- seems
> too Rube Goldbergish, and in any case I have a lot less faith in the
> whole concept now than I had before I started digging into this issue.
>
> Thoughts?
>
I noticed EXPLAIN in some regression tests. So if they all pass after
removal of this optimization, it might indicate that it was really
insignificant. But alternatively it may just be a lack of focus on this
feature in the test queries. Digging for (non-LATERAL) queries or rather
patterns where the ph_may_need optimization clearly appears to be
important sounds to me like a good SQL exercise, but I'm afraid I won't
have time for it in the next few days.
//Antonin Houska (Tony)
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Bruce Momjian | 2013-07-04 16:26:50 | Re: strange IS NULL behaviour |
| Previous Message | Robert Haas | 2013-07-04 15:53:28 | Re: Review: Patch to compute Max LSN of Data Pages |