Disallow LOCK TABLE outside a transaction block (or function), since this case

almost certainly represents user error.  Per a gripe from Sebastian Böhm
and subsequent discussion.

diff --git a/doc/src/sgml/ref/declare.sgml b/doc/src/sgml/ref/declare.sgml
index 269d2c101c4ce9ca18c50df6be5069d613505f60..744cda77726de5c8a6c011086b77451d6c44a716 100644 (file)
--- a/doc/src/sgml/ref/declare.sgml
+++ b/doc/src/sgml/ref/declare.sgml
@@ -1,5 +1,5 @@
 
 
@@ -175,10 +175,9 @@ DECLARE name [ BINARY ] [ INSENSITI
     PostgreSQL reports an error if such a
     command is used outside a transaction block.
     Use
-    ,
+     and
     
-    and
-    
+    (or )
     to define a transaction block.
    
 

diff --git a/doc/src/sgml/ref/lock.sgml b/doc/src/sgml/ref/lock.sgml
index d32e6d364c8a39fa3258251999e5dc0872f0b725..701c2a19a48f85ea8cbb8f7bc2346a76e20e37de 100644 (file)
--- a/doc/src/sgml/ref/lock.sgml
+++ b/doc/src/sgml/ref/lock.sgml
@@ -1,5 +1,5 @@
 
 
@@ -160,12 +160,15 @@ where lockmode is one of:
    
 
    
-    LOCK TABLE is useful only inside a transaction
-    block (BEGIN/COMMIT pair), since the lock
-    is dropped as soon as the transaction ends.  A LOCK
-    TABLE command appearing outside any transaction block forms a
-    self-contained transaction, so the lock will be dropped as soon as
-    it is obtained.
+    LOCK TABLE is useless outside a transaction block: the lock
+    would remain held only to the completion of the statement.  Therefore
+    PostgreSQL reports an error if LOCK
+    is used outside a transaction block.
+    Use
+     and
+    
+    (or )
+    to define a transaction block.
    
 
   

diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index b1a0fe28ca5512220d3f12a0a1ea2fcf07654cb6..1218e7cb9b86846ccb7911f9f999d77c62c41ff8 100644 (file)
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.299 2008/10/10 13:48:05 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.300 2008/11/04 00:57:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -938,6 +938,11 @@ ProcessUtility(Node *parsetree,
            break;
 
        case T_LockStmt:
+           /*
+            * Since the lock would just get dropped immediately, LOCK TABLE
+            * outside a transaction block is presumed to be user error.
+            */
+           RequireTransactionChain(isTopLevel, "LOCK TABLE");
            LockTableCommand((LockStmt *) parsetree);
            break;
 

diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
index 21f9fc26fd9128ab374cd60e6fa77f7d681500e6..d1767e95ad4cdab702466aaf5e18e3d5842246d4 100644 (file)
--- a/src/test/regress/expected/privileges.out
+++ b/src/test/regress/expected/privileges.out
@@ -45,7 +45,9 @@ INSERT INTO atest1 VALUES (1, 'one');
 DELETE FROM atest1;
 UPDATE atest1 SET a = 1 WHERE b = 'blech';
 TRUNCATE atest1;
+BEGIN;
 LOCK atest1 IN ACCESS EXCLUSIVE MODE;
+COMMIT;
 REVOKE ALL ON atest1 FROM PUBLIC;
 SELECT * FROM atest1;
  a | b 
@@ -102,8 +104,10 @@ DELETE FROM atest2; -- fail
 ERROR:  permission denied for relation atest2
 TRUNCATE atest2; -- fail
 ERROR:  permission denied for relation atest2
+BEGIN;
 LOCK atest2 IN ACCESS EXCLUSIVE MODE; -- fail
 ERROR:  permission denied for relation atest2
+COMMIT;
 COPY atest2 FROM stdin; -- fail
 ERROR:  permission denied for relation atest2
 GRANT ALL ON atest1 TO PUBLIC; -- fail
@@ -155,7 +159,9 @@ DELETE FROM atest2; -- fail
 ERROR:  permission denied for relation atest2
 TRUNCATE atest2; -- fail
 ERROR:  permission denied for relation atest2
+BEGIN;
 LOCK atest2 IN ACCESS EXCLUSIVE MODE; -- ok
+COMMIT;
 COPY atest2 FROM stdin; -- fail
 ERROR:  permission denied for relation atest2
 -- checks in subquery, both fail

diff --git a/src/test/regress/sql/privileges.sql b/src/test/regress/sql/privileges.sql
index 450d5d9d68da1102b3355c25f78d91129e6794c4..63532f7e095702e7d6df93e0bc962dd53003544d 100644 (file)
--- a/src/test/regress/sql/privileges.sql
+++ b/src/test/regress/sql/privileges.sql
@@ -48,7 +48,9 @@ INSERT INTO atest1 VALUES (1, 'one');
 DELETE FROM atest1;
 UPDATE atest1 SET a = 1 WHERE b = 'blech';
 TRUNCATE atest1;
+BEGIN;
 LOCK atest1 IN ACCESS EXCLUSIVE MODE;
+COMMIT;
 
 REVOKE ALL ON atest1 FROM PUBLIC;
 SELECT * FROM atest1;
@@ -80,7 +82,9 @@ SELECT * FROM atest1 FOR UPDATE; -- ok
 SELECT * FROM atest2 FOR UPDATE; -- fail
 DELETE FROM atest2; -- fail
 TRUNCATE atest2; -- fail
+BEGIN;
 LOCK atest2 IN ACCESS EXCLUSIVE MODE; -- fail
+COMMIT;
 COPY atest2 FROM stdin; -- fail
 GRANT ALL ON atest1 TO PUBLIC; -- fail
 
@@ -105,7 +109,9 @@ SELECT * FROM atest1 FOR UPDATE; -- fail
 SELECT * FROM atest2 FOR UPDATE; -- fail
 DELETE FROM atest2; -- fail
 TRUNCATE atest2; -- fail
+BEGIN;
 LOCK atest2 IN ACCESS EXCLUSIVE MODE; -- ok
+COMMIT;
 COPY atest2 FROM stdin; -- fail
 
 -- checks in subquery, both fail