Re: pgsql: Add isolationtester spec for old heapam.c bug

Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Tom Lane wrote:
>> guaibasaurus is not a particularly slow machine, and it's not using any
>> special build flags AFAICT.  So I'm not sure what to make of this case,
>> except that it proves the timing problem can manifest on normal builds.

> Hmm, I suppose I could fix this by using three different advisory locks
> rather than a single one.  (My assumption is that the timing dependency
> is the order in which the backends are awakened when the advisory lock
> is released.)  I would release the locks one by one rather than all
> together.

Sounds plausible.  You would probably need several seconds' pg_sleep() in
between the lock releases to ensure that even on slow/overloaded machines,
there's enough time for all wakened backends to do what they're supposed
to do.

            regards, tom lane