Don't try to print data type names in slot_store_error_callback().

The existing code tried to do syscache lookups in an already-failed
transaction, which is problematic to say the least.  After some
consideration of alternatives, the best fix seems to be to just drop
type names from the error message altogether.  The table and column
names seem like sufficient localization.  If the user is unsure what
types are involved, she can check the local and remote table
definitions.

Having done that, we can also discard the LogicalRepTypMap hash
table, which had no other use.  Arguably, LOGICAL_REP_MSG_TYPE
replication messages are now obsolete as well; but we should
probably keep them in case some other use emerges.  (The complexity
of removing something from the replication protocol would likely
outweigh any savings anyhow.)

Masahiko Sawada and Bharath Rupireddy, per complaint from Andres
Freund.  Back-patch to v10 where this code originated.

Discussion: https://postgr.es/m/20210106020229.ne5xnuu6wlondjpe@alap3.anarazel.de

1 files changed, 5 insertions, 27 deletions

diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 571b0e717e1..2f448036ea1 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -89,7 +89,6 @@ static dlist_head lsn_mapping = DLIST_STATIC_INIT(lsn_mapping);
 typedef struct SlotErrCallbackArg
 {
 	LogicalRepRelMapEntry *rel;
-	int			local_attnum;
 	int			remote_attnum;
 } SlotErrCallbackArg;
 
@@ -288,36 +287,23 @@ slot_fill_defaults(LogicalRepRelMapEntry *rel, EState *estate,
 }
 
 /*
- * Error callback to give more context info about type conversion failure.
+ * Error callback to give more context info about data conversion failures
+ * while reading data from the remote server.
  */
 static void
 slot_store_error_callback(void *arg)
 {
 	SlotErrCallbackArg *errarg = (SlotErrCallbackArg *) arg;
 	LogicalRepRelMapEntry *rel;
-	char	   *remotetypname;
-	Oid			remotetypoid,
-				localtypoid;
 
 	/* Nothing to do if remote attribute number is not set */
 	if (errarg->remote_attnum < 0)
 		return;
 
 	rel = errarg->rel;
-	remotetypoid = rel->remoterel.atttyps[errarg->remote_attnum];
-
-	/* Fetch remote type name from the LogicalRepTypMap cache */
-	remotetypname = logicalrep_typmap_gettypname(remotetypoid);
-
-	/* Fetch local type OID from the local sys cache */
-	localtypoid = get_atttype(rel->localreloid, errarg->local_attnum + 1);
-
-	errcontext("processing remote data for replication target relation \"%s.%s\" column \"%s\", "
-			   "remote type %s, local type %s",
+	errcontext("processing remote data for replication target relation \"%s.%s\" column \"%s\"",
 			   rel->remoterel.nspname, rel->remoterel.relname,
-			   rel->remoterel.attnames[errarg->remote_attnum],
-			   remotetypname,
-			   format_type_be(localtypoid));
+			   rel->remoterel.attnames[errarg->remote_attnum]);
 }
 
 /*
@@ -338,7 +324,6 @@ slot_store_cstrings(TupleTableSlot *slot, LogicalRepRelMapEntry *rel,
 
 	/* Push callback + info on the error context stack */
 	errarg.rel = rel;
-	errarg.local_attnum = -1;
 	errarg.remote_attnum = -1;
 	errcallback.callback = slot_store_error_callback;
 	errcallback.arg = (void *) &errarg;
@@ -357,7 +342,6 @@ slot_store_cstrings(TupleTableSlot *slot, LogicalRepRelMapEntry *rel,
 			Oid			typinput;
 			Oid			typioparam;
 
-			errarg.local_attnum = i;
 			errarg.remote_attnum = remoteattnum;
 
 			getTypeInputInfo(att->atttypid, &typinput, &typioparam);
@@ -366,7 +350,6 @@ slot_store_cstrings(TupleTableSlot *slot, LogicalRepRelMapEntry *rel,
 									 typioparam, att->atttypmod);
 			slot->tts_isnull[i] = false;
 
-			errarg.local_attnum = -1;
 			errarg.remote_attnum = -1;
 		}
 		else
@@ -422,7 +405,6 @@ slot_modify_cstrings(TupleTableSlot *slot, TupleTableSlot *srcslot,
 
 	/* For error reporting, push callback + info on the error context stack */
 	errarg.rel = rel;
-	errarg.local_attnum = -1;
 	errarg.remote_attnum = -1;
 	errcallback.callback = slot_store_error_callback;
 	errcallback.arg = (void *) &errarg;
@@ -446,7 +428,6 @@ slot_modify_cstrings(TupleTableSlot *slot, TupleTableSlot *srcslot,
 			Oid			typinput;
 			Oid			typioparam;
 
-			errarg.local_attnum = i;
 			errarg.remote_attnum = remoteattnum;
 
 			getTypeInputInfo(att->atttypid, &typinput, &typioparam);
@@ -455,7 +436,6 @@ slot_modify_cstrings(TupleTableSlot *slot, TupleTableSlot *srcslot,
 									 typioparam, att->atttypmod);
 			slot->tts_isnull[i] = false;
 
-			errarg.local_attnum = -1;
 			errarg.remote_attnum = -1;
 		}
 		else
@@ -579,8 +559,7 @@ apply_handle_relation(StringInfo s)
 /*
  * Handle TYPE message.
  *
- * Note we don't do local mapping here, that's done when the type is
- * actually used.
+ * This is now vestigial; we read the info and discard it.
  */
 static void
 apply_handle_type(StringInfo s)
@@ -588,7 +567,6 @@ apply_handle_type(StringInfo s)
 	LogicalRepTyp typ;
 
 	logicalrep_read_typ(s, &typ);
-	logicalrep_typmap_update(&typ);
 }
 
 /*