Re: logical decoding bug: segfault in ReorderBufferToastReplace()

On 12/13/19 16:13, Jeremy Schneider wrote:
> On 12/11/19 08:35, Andres Freund wrote:
>> Seems like we clearly should add an elog(ERROR) here, so we error out,
>> rather than crash.
> done - in the commit that I replied to when I started this thread :)
>
> https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=69f883fef14a3fc5849126799278abcc43f40f56

Another PostgreSQL user ran into this issue. This time on version 12.5 -
so instead of a crash they got the error message from the commit.

ERROR: XX000: could not open relation with OID 0
LOCATION: ReorderBufferToastReplace, reorderbuffer.c:305

Upon seeing this error message, I realized that the base relation OID
would be very useful when the toast relation OID is "0".

Would this patch work to show that?

diff --git a/src/backend/replication/logical/reorderbuffer.c
b/src/backend/replication/logical/reorderbuffer.c
index 2d9e1279bb..b90603b051 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -4598,8 +4598,8 @@ ReorderBufferToastReplace(ReorderBuffer *rb,
ReorderBufferTXN *txn,

        toast_rel = RelationIdGetRelation(relation->rd_rel->reltoastrelid);
        if (!RelationIsValid(toast_rel))
-               elog(ERROR, "could not open relation with OID %u",
-                        relation->rd_rel->reltoastrelid);
+               elog(ERROR, "could not open toast relation with OID %u
(base relation with OID %u)",
+                        relation->rd_rel->reltoastrelid,
relation->rd_rel->oid);

        toast_desc = RelationGetDescr(toast_rel);

Thoughts?

-Jeremy

--
Jeremy Schneider
Database Engineer
Amazon Web Services