Alvaro Herrera <[email protected]> wrote:
> (I omitted the last three patches in the series, and
> squashed my proposed changes into 0003, as announced in my previous
> posting.)
I've updated the comment about on-disk attributes in repack_store_change(),
but when verifying it, I hit an error when more than one UPDATEs (in separate
transactions) were executed during a single run of REPACK.
The problem is that reorderbuffer.c sets up an internal (sub)transaction
before replaying each decoded transaction. Therefore the tuple slot should not
be allocated in TopTransactionContext. I chose TopMemoryContext instead.
BTW, if you want to verify that the updated comment is correct, just add
elog(ERROR) next to it and run repack_toast.spec. The statement
UPDATE repack_test SET i=3 where i=1;
will then reach it.
--
Antonin Houska
Web: https://www.cybertec-postgresql.com
diff --git a/src/backend/replication/pgoutput_repack/pgoutput_repack.c b/src/backend/replication/pgoutput_repack/pgoutput_repack.c
index cc9ce615b18..5fe3115509e 100644
--- a/src/backend/replication/pgoutput_repack/pgoutput_repack.c
+++ b/src/backend/replication/pgoutput_repack/pgoutput_repack.c
@@ -202,7 +202,11 @@ repack_store_change(LogicalDecodingContext *ctx, Relation relation,
/* Initialize the slot, if not done already */
if (dstate->slot == NULL)
{
- MemoryContextSwitchTo(oldcxt);
+ /*
+ * We are in the decoding worker, so no worries about polluting
+ * memory of the backend executing REPACK.
+ */
+ MemoryContextSwitchTo(TopMemoryContext);
dstate->slot = MakeSingleTupleTableSlot(desc, &TTSOpsHeapTuple);
MemoryContextSwitchTo(dstate->change_cxt);
}
@@ -247,8 +251,8 @@ repack_store_change(LogicalDecodingContext *ctx, Relation relation,
* attributes (those actually should never appear on disk), so
* only TOASTed attribute can be seen here.
*
- * FIXME in what circumstances can an ONDISK attr appear? Why
- * aren't these written separately?
+ * We get here if the table has external values but only
+ * in-line values are being updated now.
*/
Assert(VARATT_IS_EXTERNAL_ONDISK(varlen));
}
