GUC assign hooks that look at external state in deciding whether a

tglsfdc · tglsfdc · commit b120485f9cf5 · 2004-09-24T19:43:03.000Z
setting is valid must ignore that state and permit the assignment anyway
when source is PGC_S_OVERRIDE.  Otherwise they may disallow a rollback
at transaction abort, which is The Wrong Thing.  Per example from
Michael Fuhr 12-Sep-04.
diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/variable.c,v 1.103 2004/08/31 19:28:51 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/variable.c,v 1.104 2004/09/24 19:42:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -481,7 +481,8 @@ assign_XactIsoLevel(const char *value, bool doit, GucSource source)
 			ereport(ERROR,
 					(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
 					 errmsg("SET TRANSACTION ISOLATION LEVEL must be called before any query")));
-		else
+		/* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
+		else if (source != PGC_S_OVERRIDE)
 			return NULL;
 	}
 	if (IsSubTransaction())
@@ -490,7 +491,8 @@ assign_XactIsoLevel(const char *value, bool doit, GucSource source)
 			ereport(ERROR,
 					(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
 					 errmsg("SET TRANSACTION ISOLATION LEVEL must not be called in a subtransaction")));
-		else
+		/* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
+		else if (source != PGC_S_OVERRIDE)
 			return NULL;
 	}
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.238 2004/08/31 22:43:58 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.239 2004/09/24 19:43:03 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -5532,7 +5532,8 @@ assign_stage_log_stats(bool newval, bool doit, GucSource source)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
-		else
+		/* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
+		else if (source != PGC_S_OVERRIDE)
 			return false;
 	}
 	return true;
@@ -5550,7 +5551,8 @@ assign_log_stats(bool newval, bool doit, GucSource source)
 					 errmsg("cannot enable \"log_statement_stats\" when "
 							"\"log_parser_stats\", \"log_planner_stats\", "
 							"or \"log_executor_stats\" is true")));
-		else
+		/* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
+		else if (source != PGC_S_OVERRIDE)
 			return false;
 	}
 	return true;
@@ -5566,7 +5568,9 @@ assign_transaction_read_only(bool newval, bool doit, GucSource source)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("cannot set transaction read-write mode inside a read-only transaction")));
-		return false;
+		/* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
+		else if (source != PGC_S_OVERRIDE)
+			return false;
 	}
 	return true;
 }

Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@`
`9`	`9`	`*`
`10`	`10`	`*`
`11`	`11`	`* IDENTIFICATION`
`12`		`- * $PostgreSQL: pgsql/src/backend/commands/variable.c,v 1.103 2004/08/31 19:28:51 tgl Exp $`
	`12`	`+ * $PostgreSQL: pgsql/src/backend/commands/variable.c,v 1.104 2004/09/24 19:42:58 tgl Exp $`
`13`	`13`	`*`
`14`	`14`	`*-------------------------------------------------------------------------`
`15`	`15`	`*/`
`@@ -481,7 +481,8 @@ assign_XactIsoLevel(const char *value, bool doit, GucSource source)`
`481`	`481`	`ereport(ERROR,`
`482`	`482`	`(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),`
`483`	`483`	`errmsg("SET TRANSACTION ISOLATION LEVEL must be called before any query")));`
`484`		`- else`
	`484`	`+ /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */`
	`485`	`+ else if (source != PGC_S_OVERRIDE)`
`485`	`486`	`return NULL;`
`486`	`487`	`}`
`487`	`488`	`if (IsSubTransaction())`
`@@ -490,7 +491,8 @@ assign_XactIsoLevel(const char *value, bool doit, GucSource source)`
`490`	`491`	`ereport(ERROR,`
`491`	`492`	`(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),`
`492`	`493`	`errmsg("SET TRANSACTION ISOLATION LEVEL must not be called in a subtransaction")));`
`493`		`- else`
	`494`	`+ /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */`
	`495`	`+ else if (source != PGC_S_OVERRIDE)`
`494`	`496`	`return NULL;`
`495`	`497`	`}`
`496`	`498`