From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Andres Freund <andres(at)anarazel(dot)de> |
Cc: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Michael Paquier <michael(at)paquier(dot)xyz>, Justin Pryzby <pryzby(at)telsasoft(dot)com>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: clean up docs for v12 |
Date: | 2019-04-22 18:17:48 |
Message-ID: | 20637.1555957068@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Andres Freund <andres(at)anarazel(dot)de> writes:
> On 2019-04-22 13:27:17 -0400, Tom Lane wrote:
>> I wonder
>> also if it wouldn't be smart to explicitly check that the "guaranteeing"
>> column is not attisdropped.
> Yea, that probably would be smart. I don't think there's an active
> problem, because we remove NOT NULL when deleting an attribute, but it
> seems good to be doubly sure / explain why that's safe:
> /* Remove any NOT NULL constraint the column may have */
> attStruct->attnotnull = false;
> I'm a bit unsure whether to make it an assert, elog(ERROR) or just not
> assume column presence?
I'd just make the code look like
/*
* If it's NOT NULL then it must be present in every tuple,
* unless there's a "missing" entry that could provide a non-null
* value for it. Out of paranoia, also check !attisdropped.
*/
if (att->attnotnull &&
!att->atthasmissing &&
!att->attisdropped)
guaranteed_column_number = attnum;
I don't think the extra check is so expensive as to be worth obsessing
over.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Andres Freund | 2019-04-22 18:20:50 | Re: pg_dump is broken for partition tablespaces |
Previous Message | Alvaro Herrera | 2019-04-22 18:16:28 | Re: pg_dump is broken for partition tablespaces |