Patch to LOCK multiple tables in one LOCK command.

Neil Padgett

diff --git a/doc/src/sgml/ref/lock.sgml b/doc/src/sgml/ref/lock.sgml
index 20530d75d712da6748c1af05fbf6e0bac51b3fb4..b66f42e7ebc9559c7cd69e3d374e4c997bfbcdb6 100644 (file)
--- a/doc/src/sgml/ref/lock.sgml
+++ b/doc/src/sgml/ref/lock.sgml
@@ -1,5 +1,5 @@
 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/lock.sgml,v 1.26 2001/08/04 22:01:38 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/lock.sgml,v 1.27 2001/08/10 14:30:14 momjian Exp $
 Postgres documentation
 -->
 
@@ -15,7 +15,7 @@ Postgres documentation
    LOCK
   </refname>
   <refpurpose>
-   Explicitly lock a table inside a transaction
+   Explicitly lock a table / tables inside a transaction
   </refpurpose>
  </refnamediv>
  <refsynopsisdiv>
@@ -23,8 +23,8 @@ Postgres documentation
    <date>2001-07-09</date>
   </refsynopsisdivinfo>
   <synopsis>
-LOCK [ TABLE ] <replaceable class="PARAMETER">name</replaceable>
-LOCK [ TABLE ] <replaceable class="PARAMETER">name</replaceable> IN <replaceable class="PARAMETER">lockmode</replaceable> MODE
+LOCK [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...]
+LOCK [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...] IN <replaceable class="PARAMETER">lockmode</replaceable> MODE
 
 where <replaceable class="PARAMETER">lockmode</replaceable> is one of:
 
@@ -373,6 +373,7 @@ ERROR <replaceable class="PARAMETER">name</replaceable>: Table does not exist.
      An example for this rule was given previously when discussing the 
      use of SHARE ROW EXCLUSIVE mode rather than SHARE mode.
     </para>
+
    </listitem>
   </itemizedlist>
 
@@ -383,6 +384,12 @@ ERROR <replaceable class="PARAMETER">name</replaceable>: Table does not exist.
    </para>
   </note>
 
+  <para>
+   When locking multiple tables, the command LOCK a, b; is equivalent to LOCK
+   a; LOCK b;. The tables are locked one-by-one in the order specified in the
+   <command>LOCK</command> command.
+  </para>
+
   <refsect2 id="R2-SQL-LOCK-3">
    <refsect2info>
     <date>1999-06-08</date>
@@ -406,6 +413,7 @@ ERROR <replaceable class="PARAMETER">name</replaceable>: Table does not exist.
    <para>
     <command>LOCK</command> works only inside transactions.
    </para>
+
   </refsect2>
  </refsect1>
   

diff --git a/src/backend/commands/command.c b/src/backend/commands/command.c
index 37814cdcd3841b2d577df6b65d3c7afc71b69933..3d02fdb5fd2f34b5b339a111f55985c8578fae83 100644 (file)
--- a/src/backend/commands/command.c
+++ b/src/backend/commands/command.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.138 2001/08/04 22:01:38 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.139 2001/08/10 14:30:14 momjian Exp $
  *
  * NOTES
  *   The PerformAddAttribute() code, like most of the relation
@@ -1984,8 +1984,7 @@ needs_toast_table(Relation rel)
        MAXALIGN(data_length);
    return (tuple_length > TOAST_TUPLE_THRESHOLD);
 }
-
-
+   
 /*
  *
  * LOCK TABLE
@@ -1994,26 +1993,38 @@ needs_toast_table(Relation rel)
 void
 LockTableCommand(LockStmt *lockstmt)
 {
-   Relation    rel;
-   int         aclresult;
-
-   rel = heap_openr(lockstmt->relname, NoLock);
-
-   if (rel->rd_rel->relkind != RELKIND_RELATION)
-       elog(ERROR, "LOCK TABLE: %s is not a table", lockstmt->relname);
-
-   if (lockstmt->mode == AccessShareLock)
-       aclresult = pg_aclcheck(lockstmt->relname, GetUserId(), ACL_SELECT);
-   else
-       aclresult = pg_aclcheck(lockstmt->relname, GetUserId(),
-                               ACL_UPDATE | ACL_DELETE);
+   List *p;
+   Relation rel;
+   
+   /* Iterate over the list and open, lock, and close the relations
+      one at a time
+    */
 
-   if (aclresult != ACLCHECK_OK)
-       elog(ERROR, "LOCK TABLE: permission denied");
+       foreach(p, lockstmt->rellist)
+       {
+           char* relname = strVal(lfirst(p));
+           int         aclresult;
+           
+           rel = heap_openr(relname, NoLock);
+
+           if (rel->rd_rel->relkind != RELKIND_RELATION)
+               elog(ERROR, "LOCK TABLE: %s is not a table", 
+                    relname);
+           
+           if (lockstmt->mode == AccessShareLock)
+               aclresult = pg_aclcheck(relname, GetUserId(),
+                                       ACL_SELECT);
+           else
+               aclresult = pg_aclcheck(relname, GetUserId(),
+                                       ACL_UPDATE | ACL_DELETE);
 
-   LockRelation(rel, lockstmt->mode);
+           if (aclresult != ACLCHECK_OK)
+               elog(ERROR, "LOCK TABLE: permission denied");
 
-   heap_close(rel, NoLock);    /* close rel, keep lock */
+           LockRelation(rel, lockstmt->mode);
+           
+           heap_close(rel, NoLock);    /* close rel, keep lock */
+       }
 }
 
 

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 0d9aef03edff98efa5be45078eb98041ad80859b..ddb5822cde2cd903e3e4a85073e4eb59162017ea 100644 (file)
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.150 2001/08/04 22:01:38 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.151 2001/08/10 14:30:14 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2425,8 +2425,8 @@ _copyLockStmt(LockStmt *from)
 {
    LockStmt   *newnode = makeNode(LockStmt);
 
-   if (from->relname)
-       newnode->relname = pstrdup(from->relname);
+   Node_Copy(from, newnode, rellist);
+   
    newnode->mode = from->mode;
 
    return newnode;

diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 74a88555c5d3f5f5ab635345a81d7b0d32640328..06cdeef9ad8ed4380ac8424ee37bf24fd4d84916 100644 (file)
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.98 2001/08/04 22:01:38 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.99 2001/08/10 14:30:14 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1283,7 +1283,7 @@ _equalDropUserStmt(DropUserStmt *a, DropUserStmt *b)
 static bool
 _equalLockStmt(LockStmt *a, LockStmt *b)
 {
-   if (!equalstr(a->relname, b->relname))
+   if (!equal(a->rellist, b->rellist))
        return false;
    if (a->mode != b->mode)
        return false;

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 96690aa90cf0c57329a3d57deb72778511d9baca..2a08413dafe91920be0cce7346b45aafd51ac740 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.241 2001/08/06 05:42:48 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.242 2001/08/10 14:30:14 momjian Exp $
  *
  * HISTORY
  *   AUTHOR            DATE            MAJOR EVENT
@@ -3281,11 +3281,11 @@ DeleteStmt:  DELETE FROM relation_expr where_clause
                }
        ;
 
-LockStmt:  LOCK_P opt_table relation_name opt_lock
+LockStmt:  LOCK_P opt_table relation_name_list opt_lock
                {
                    LockStmt *n = makeNode(LockStmt);
 
-                   n->relname = $3;
+                   n->rellist = $3;
                    n->mode = $4;
                    $$ = (Node *)n;
                }

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index ad7bcc2e0f3b9872465edfa5a00576ae4ee30d0d..704b8cab4a734ae59e3c8eaa5dadff2f23d6d804 100644 (file)
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.138 2001/08/04 22:01:39 momjian Exp $
+ * $Id: parsenodes.h,v 1.139 2001/08/10 14:30:15 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -760,7 +760,7 @@ typedef struct VariableResetStmt
 typedef struct LockStmt
 {
    NodeTag     type;
-   char       *relname;        /* relation to lock */
+   List       *rellist;        /* relations to lock */
    int         mode;           /* lock mode */
 } LockStmt;
 

diff --git a/src/interfaces/ecpg/preproc/preproc.y b/src/interfaces/ecpg/preproc/preproc.y
index 88330ad3c1de5a9d5af76a53b01ed43e8ca6f059..09180f85c9c28b38ae68378f4f0e392a08295277 100644 (file)
--- a/src/interfaces/ecpg/preproc/preproc.y
+++ b/src/interfaces/ecpg/preproc/preproc.y
@@ -2421,7 +2421,7 @@ DeleteStmt:  DELETE FROM relation_expr where_clause
                }
        ;
 
-LockStmt:  LOCK_P opt_table relation_name opt_lock
+LockStmt:  LOCK_P opt_table relation_name_list opt_lock
                {
                    $$ = cat_str(4, make_str("lock"), $2, $3, $4);
                }