Re: Doubt about AccessExclusiveLock in ALTER TABLE .. SET ( .. );

On Fri, Jul 31, 2015 at 11:28 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>
>> @@ -57,7 +57,8 @@ static relopt_bool boolRelOpts[] =
>
> If we go through this list, I'd rather make informed decisions about
> each reloption. Otherwise we're going to get patches for each of them
> separately over the next versions.

Just dropping quickly a reply: I meant table relopts only, excluding
the index stuff for now regarding the isolation tests.

>> + AccessExclusiveLock
>> + foreach(cell, defList)
>> + {
>> + DefElem *def = (DefElem *) lfirst(cell);
>> + int i;
>> +
>> + for (i = 0; relOpts[i]; i++)
>> + {
>> + if (pg_strncasecmp(relOpts[i]->name, def->defname, relOpts[i]->namelen + 1) == 0)
>> + {
>> + if (lockmode < relOpts[i]->lockmode)
>> + lockmode = relOpts[i]->lockmode;
>> + }
>> + }
>> + }
>> +
>> + return lockmode;
>> +}
>
> We usually don't compare lock values that way, i.e. there's not
> guaranteed to be a strict monotonicity between lock levels. I don't
> really agree with that policy, but it's nonetheless there.

Yeah, there are some in lock.c but that's rather localized.
--
Michael