Re: executor relation handling

On 1 October 2018 at 06:18, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> It occurred to me that it'd be reasonable to insist that the caller
> holds a lock *at least as strong* as the one being recorded in the RTE,
> and that there's also been discussions about verifying that some lock
> is held when something like heap_open(foo, NoLock) is attempted.
> So I dusted off the part of 0001 that did that, producing the
> attached delta patch.

My imagination struggles to think of a case, but perhaps one day in
the future we might have a lock manager that coordinates locks on
multiple nodes. If so, is there not a risk that one day we might have
a lock level greater than AccessExclusiveLock, meaning the following
would get broken:

+ for (slockmode = lockmode + 1;
+ slockmode <= AccessExclusiveLock;
+ slockmode++)

For index strategies we do:

#define BTGreaterStrategyNumber 5

#define BTMaxStrategyNumber 5

So would it not be better to add the following to lockdefs.h?

#define MaxLockLevel 8

then use that to terminate the loop.

--
David Rowley http://www.2ndQuadrant.com/
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