Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> On that note, any chance you remember why you increased MAX_LOCKMODE by
> 2 to 10 back in 2001 although AccessExclusiveLock is 8? The relevant
> commit is 4fe42dfbc3bafa0ea615239d716a6b37d67da253 .
Probably because it seemed like a round number, which 9 wasn't ...
keep in mind that this data structure is nominally intended to support
other lock semantics besides what LockConflicts[] defines. (BTW,
it's a conceptual error to imagine that the numerical values of the
lock mode codes define a strict "strength" ordering, which is another
reason I don't care for your patch.)
regards, tom lane