I wrote:
> ... What I would have expected is crashes on the very
> similar updates to pgbench_branches, which is designed to be
> high-contention. It might be that there is some other effect going on
> here that explains why that wasn't happening. Need to go back and look
> more closely.
... and the answer to that is that pgbench_branches isn't subject to the
bug, because its only pass-by-reference column happens to be filled with
all NULLs by the initialization step, unlike the accounts filler column
which happens to be filled with non-null strings. Null values mean no
dangling pointers and no chance for a memory management issue. So you
could have run this all day and never seen a crash on pgbench_branches
updates. (If you manually set the filler column non-null before
starting a run, the unpatched code crashes instantly, even with a
non-bollixed pgbench.)
So, nothing to see here except lack of test coverage, move along.
regards, tom lane
