Re: [PATCH] Corruption Issue: Fix missing tts_tid in ExecForceStoreHeapTuple

On 30/10/2026 18:11, Nathan Bossart wrote:
> --- a/src/backend/executor/execTuples.c
> +++ b/src/backend/executor/execTuples.c
> @@ -1752,6 +1752,8 @@ ExecForceStoreHeapTuple(HeapTuple tuple,
> TupleTableSlot *slot,
> bool shouldFree)
> {
> + ItemPointerData tid = tuple->t_self;
> +
> if (TTS_IS_HEAPTUPLE(slot))
> {
> ExecStoreHeapTuple(tuple, slot, shouldFree);
> @@ -1784,6 +1786,13 @@ ExecForceStoreHeapTuple(HeapTuple tuple,
> pfree(tuple);
> }
> }
> +
> + /*
> + * ExecClearTuple() invalidated the slot's TID, so we need to set it again
> + * here. Note that the tuple might have already been freed, so we use the
> + * copy of its TID that we saved above.
> + */
> + slot->tts_tid = tid;
> }
>
> /*
The comment sounds wrong to me. This isn't restoring the old TID that
was in the slot previously, it's setting the new TID from 'tuple'. Or am
I missing something?

For same reason, the local variable seems pointless; you could just do:

slot->tts_tid = tuple->t_self;

The comment in Greg's earlier version (v9) said:

> + /*
> + * Store the TID from the local copy taken on entry since the stores above
> + * may have freed the tuple.
> + */
> + slot->tts_tid = tid;

But I don't see how the store might've free'd the tuple. If it did, we'd
have trouble anyway.

- Heikki