Re: row filtering for logical replication

On Mon, Nov 15, 2021 at 5:09 PM tanghy(dot)fnst(at)fujitsu(dot)com
<tanghy(dot)fnst(at)fujitsu(dot)com> wrote:
>
> I met a problem when using "ALTER PUBLICATION ... SET TABLE ... WHERE ...", the
> publisher was crashed after executing this statement.
>
>
>
> Backtrace is attached. I think maybe the problem is related to the below change in 0003 patch:
>
> + free(entry->exprstate);
>

I had a look at this crash problem and could reproduce it.

I made the following changes and it seemed to resolve the problem:

diff --git a/src/backend/replication/pgoutput/pgoutput.c
b/src/backend/replication/pgoutput/pgoutput.c
index e7f2fd4bad..f0cb9b8265 100644
--- a/src/backend/replication/pgoutput/pgoutput.c
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -969,8 +969,6 @@ pgoutput_row_filter_init(PGOutputData *data,
Relation relation, RelationSyncEntr
oldctx = MemoryContextSwitchTo(CacheMemoryContext);
rfnode = n_filters > 1 ? makeBoolExpr(AND_EXPR, rfnodes,
-1) : linitial(rfnodes);
entry->exprstate = pgoutput_row_filter_init_expr(rfnode);
-
- list_free(rfnodes);
}

entry->rowfilter_valid = true;
@@ -1881,7 +1879,7 @@ rel_sync_cache_relation_cb(Datum arg, Oid relid)
}
if (entry->exprstate != NULL)
{
- free(entry->exprstate);
+ pfree(entry->exprstate);
entry->exprstate = NULL;
}
}

Regards,
Greg Nancarrow
Fujitsu Australia