| From: | Peter Geoghegan <pg(at)bowt(dot)ie> |
|---|---|
| To: | Jesper Pedersen <jesper(dot)pedersen(at)redhat(dot)com> |
| Cc: | Floris Van Nee <florisvannee(at)optiver(dot)com>, David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>, Dmitry Dolgov <9erthalion6(at)gmail(dot)com>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Thomas Munro <thomas(dot)munro(at)gmail(dot)com>, James Coleman <jtc331(at)gmail(dot)com>, Rafia Sabih <rafia(dot)pghackers(at)gmail(dot)com>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, Bhushan Uparkar <bhushan(dot)uparkar(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> |
| Subject: | Re: Index Skip Scan |
| Date: | 2020-01-22 18:40:33 |
| Message-ID: | CAH2-Wzm3fjNHfn06nZK9XgmoXc9c8LkFyJeZJ0yC0CyVM_xQNA@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Tue, Jan 21, 2020 at 9:06 AM Jesper Pedersen
<jesper(dot)pedersen(at)redhat(dot)com> wrote:
> If you apply the attached patch on master it will fail the test suite;
> did you mean something else ?
Yeah, this is exactly what I had in mind for the _bt_readpage() assertion.
As I said, it isn't a great sign that this kind of assertion is even
necessary in index access method code (code like bufmgr.c is another
matter). Usually it's just obvious that a buffer lock is held. I can't
really blame this patch for that, though. You could say the same thing
about the existing "buffer pin held" _bt_readpage() assertion. It's
good that it verifies what is actually a fragile assumption, even
though I'd prefer to not make a fragile assumption.
--
Peter Geoghegan
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Robert Haas | 2020-01-22 18:53:08 | Re: making the backend's json parser work in frontend code |
| Previous Message | Georgios Kokolatos | 2020-01-22 17:36:20 | Re: Duplicate Workers entries in some EXPLAIN plans |