small adjustments to error messages + more locks

funbringer · funbringer · commit a27dfd6cadc1 · 2017-05-19T19:54:15.000+03:00
diff --git a/expected/pathman_expressions.out b/expected/pathman_expressions.out
@@ -20,7 +20,7 @@ SELECT create_hash_partitions('test_exprs.hash_rel', 'random()', 4);
 ERROR:  functions in partitioning expression must be marked IMMUTABLE
 \set VERBOSITY default
 SELECT create_hash_partitions('test_exprs.hash_rel', 'value * value2))', 4);
-ERROR:  partitioning expression parse error
+ERROR:  failed to parse partitioning expression
 DETAIL:  syntax error at or near ")"
 QUERY:  SELECT public.validate_expression(parent_relid, expression)
 CONTEXT:  PL/pgSQL function prepare_for_partitioning(regclass,text,boolean) line 9 at PERFORM
@@ -29,7 +29,7 @@ SQL statement "SELECT public.prepare_for_partitioning(parent_relid,
 												 partition_data)"
 PL/pgSQL function create_hash_partitions(regclass,text,integer,boolean,text[],text[]) line 4 at PERFORM
 SELECT create_hash_partitions('test_exprs.hash_rel', 'value * value3', 4);
-ERROR:  partitioning expression analyze error
+ERROR:  failed to analyze partitioning expression
 DETAIL:  column "value3" does not exist
 HINT:  Perhaps you meant to reference the column "hash_rel.value" or the column "hash_rel.value2".
 QUERY:  SELECT public.validate_expression(parent_relid, expression)
diff --git a/src/pl_funcs.c b/src/pl_funcs.c
@@ -597,9 +597,9 @@ validate_relname(PG_FUNCTION_ARGS)
 }
 
 /*
- * Validate a partitioning expression
- * We need this in range functions because we do many things
- * before actual partitioning.
+ * Validate a partitioning expression.
+ * NOTE: We need this in range functions because
+ * we do many things before actual partitioning.
  */
 Datum
 validate_expression(PG_FUNCTION_ARGS)
@@ -610,6 +610,9 @@ validate_expression(PG_FUNCTION_ARGS)
 	/* Fetch relation's Oid */
 	relid = PG_GETARG_OID(0);
 
+	/* Protect relation from concurrent drop */
+	LockRelationOid(relid, AccessShareLock);
+
 	if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(relid)))
 		ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 						errmsg("relation \"%u\" does not exist", relid),
@@ -623,7 +626,11 @@ validate_expression(PG_FUNCTION_ARGS)
 	else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 						 errmsg("'expression' should not be NULL")));
 
+	/* Perform some checks */
 	cook_partitioning_expression(relid, expression, NULL);
+
+	UnlockRelationOid(relid, AccessShareLock);
+
 	PG_RETURN_VOID();
 }
 
@@ -763,7 +770,7 @@ add_to_pathman_config(PG_FUNCTION_ARGS)
 	else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 						 errmsg("'parent_relid' should not be NULL")));
 
-	/* Lock relation */
+	/* Protect relation from concurrent modification */
 	xact_lock_rel_exclusive(relid, true);
 
 	/* Check that relation exists */
diff --git a/src/relation_info.c b/src/relation_info.c
@@ -592,7 +592,7 @@ parse_partitioning_expression(const Oid relid,
 		FlushErrorState();
 
 		error->detail = error->message;
-		error->message = "partitioning expression parse error";
+		error->message = "failed to parse partitioning expression";
 		error->sqlerrcode = ERRCODE_INVALID_PARAMETER_VALUE;
 		error->cursorpos = 0;
 		error->internalpos = 0;
@@ -700,7 +700,7 @@ cook_partitioning_expression(const Oid relid,
 		FlushErrorState();
 
 		error->detail = error->message;
-		error->message = "partitioning expression analyze error";
+		error->message = "failed to analyze partitioning expression";
 		error->sqlerrcode = ERRCODE_INVALID_PARAMETER_VALUE;
 		error->cursorpos = 0;
 		error->internalpos = 0;
