Mark Dilger <mark.dilger@enterprisedb.com> writes:
> On Jun 8, 2021, at 3:55 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I suppose that either apply_dispatch or LogicalRepApplyLoop needs to
>> grow some more snapshot management logic, but I've not looked at that
>> code much, so I don't have an opinion on just where to add it.
> I was looking at those for other reasons prior to hitting this bug.
After looking at it a bit, I see a couple of options:
1. Just wrap the call of ExecuteTruncateGuts with
PushActiveSnapshot(GetTransactionSnapshot()) and PopActiveSnapshot().
2. Decide that we ought to ensure that a snapshot exists throughout
most of this code. It's not entirely obvious to me that there is no
code path reachable from, say, apply_handle_truncate's collection of
relation OIDs that needs a snapshot. If we went for that, I'd think
the right solution is to do PushActiveSnapshot right after each
ensure_transaction call, and then PopActiveSnapshot on the way out of
the respective subroutine. We could then drop the snapshot management
calls that are currently associated with the executor state.
> My purpose was to figure out how to get the code to respect
> privileges. Perhaps the solution to these two issues is related.
> I don't know yet.
Doesn't seem tremendously related. But yeah, there is Stuff That
Is Missing in these code paths.
regards, tom lane