Add an option to AlterTableCreateToastTable() to allow its caller to force

a toast table to be built, even if the sum-of-column-widths calculation
indicates one isn't needed.  This is needed by pg_migrator because if the
old table has a toast table, we have to migrate over the toast table since
it might contain some live data, even though subsequent column drops could
mean that no recently-added rows could require toasting.

diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c
index 5574b448ed64d28267806d01d6cc703d6202e0ef..ff9499ca35bf534d81e5d864b14680a2b765f934 100644 (file)
--- a/src/backend/catalog/toasting.c
+++ b/src/backend/catalog/toasting.c
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/catalog/toasting.c,v 1.14 2009/03/31 22:12:46 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/catalog/toasting.c,v 1.15 2009/05/07 22:58:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -33,21 +33,25 @@
 
 
 static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
-                                  Datum reloptions);
+                                  Datum reloptions, bool force);
 static bool needs_toast_table(Relation rel);
 
 
 /*
  * AlterTableCreateToastTable
  *             If the table needs a toast table, and doesn't already have one,
- *             then create a toast table for it.
+ *             then create a toast table for it.  (With the force option, make
+ *             a toast table even if it appears unnecessary.)
+ *
+ * reloptions for the toast table can be passed, too.  Pass (Datum) 0
+ * for default reloptions.
  *
  * We expect the caller to have verified that the relation is a table and have
  * already done any necessary permission checks.  Callers expect this function
  * to end with CommandCounterIncrement if it makes any changes.
  */
 void
-AlterTableCreateToastTable(Oid relOid, Datum reloptions)
+AlterTableCreateToastTable(Oid relOid, Datum reloptions, bool force)
 {
        Relation        rel;
 
@@ -59,7 +63,7 @@ AlterTableCreateToastTable(Oid relOid, Datum reloptions)
        rel = heap_open(relOid, AccessExclusiveLock);
 
        /* create_toast_table does all the work */
-       (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions);
+       (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, force);
 
        heap_close(rel, NoLock);
 }
@@ -85,7 +89,7 @@ BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
                                                relName)));
 
        /* create_toast_table does all the work */
-       if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0))
+       if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0, false))
                elog(ERROR, "\"%s\" does not require a toast table",
                         relName);
 
@@ -101,7 +105,8 @@ BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
  * bootstrap they can be nonzero to specify hand-assigned OIDs
  */
 static bool
-create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid, Datum reloptions)
+create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
+                                  Datum reloptions, bool force)
 {
        Oid                     relOid = RelationGetRelid(rel);
        HeapTuple       reltup;
@@ -139,8 +144,12 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid, Datum reloptio
 
        /*
         * Check to see whether the table actually needs a TOAST table.
+        *
+        * Caller can optionally override this check.  (Note: at present
+        * no callers in core Postgres do so, but this option is needed by
+        * pg_migrator.)
         */
-       if (!needs_toast_table(rel))
+       if (!force && !needs_toast_table(rel))
                return false;
 
        /*

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 18f316dd517666a628a19b85d3c1a0af8d01b598..08c09ed435ec1e47e38f92ecdea48265c24cc1c7 100644 (file)
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/commands/cluster.c,v 1.183 2009/03/31 22:12:46 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/commands/cluster.c,v 1.184 2009/05/07 22:58:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -741,7 +741,7 @@ make_new_heap(Oid OIDOldHeap, const char *NewName, Oid NewTableSpace)
                if (isNull)
                        reloptions = (Datum) 0;
        }
-       AlterTableCreateToastTable(OIDNewHeap, reloptions);
+       AlterTableCreateToastTable(OIDNewHeap, reloptions, false);
 
        if (OidIsValid(toastid))
                ReleaseSysCache(tuple);

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 25c58fbbd45c002ba848a45434dbff32b2274099..b910497f1502bcf260547793f888ca184892172e 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.281 2009/03/31 22:12:47 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.282 2009/05/07 22:58:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2584,7 +2584,7 @@ ATRewriteCatalogs(List **wqueue)
                        (tab->subcmds[AT_PASS_ADD_COL] ||
                         tab->subcmds[AT_PASS_ALTER_TYPE] ||
                         tab->subcmds[AT_PASS_COL_ATTRS]))
-                       AlterTableCreateToastTable(tab->relid, (Datum) 0);
+                       AlterTableCreateToastTable(tab->relid, (Datum) 0, false);
        }
 }
 

diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 2ff4150f601a1af4225c30629bf5e366ca7e022e..03461a235af89e94fcc413e62e15efb43a9bc415 100644 (file)
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.323 2009/02/08 18:02:27 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.324 2009/05/07 22:58:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2953,7 +2953,7 @@ OpenIntoRel(QueryDesc *queryDesc)
 
        (void) heap_reloptions(RELKIND_TOASTVALUE, reloptions, true);
 
-       AlterTableCreateToastTable(intoRelationId, reloptions);
+       AlterTableCreateToastTable(intoRelationId, reloptions, false);
 
        /*
         * And open the constructed table for writing.

diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 6c6b13e17ef43c00a40df86c6c6136b5242c0a83..63aca25ebdf42478dd2b302d385f86846cc5edd5 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 1.306 2009/02/02 19:31:39 alvherre Exp $
+ *       $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.307 2009/05/07 22:58:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -442,10 +442,13 @@ ProcessUtility(Node *parsetree,
                                                                                                                        "toast",
                                                                                                                        validnsps,
                                                                                                                        true, false);
-                                               (void) heap_reloptions(RELKIND_TOASTVALUE, toast_options,
+                                               (void) heap_reloptions(RELKIND_TOASTVALUE,
+                                                                                          toast_options,
                                                                                           true);
 
-                                               AlterTableCreateToastTable(relOid, toast_options);
+                                               AlterTableCreateToastTable(relOid,
+                                                                                                  toast_options,
+                                                                                                  false);
                                        }
                                        else
                                        {

diff --git a/src/include/catalog/toasting.h b/src/include/catalog/toasting.h
index 2d5eb61d29a16e49128a44f7d73b1ba2c2dbf9d8..f363cb0cae62a64f6ad354a5cb6a7474c0fede24 100644 (file)
--- a/src/include/catalog/toasting.h
+++ b/src/include/catalog/toasting.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/toasting.h,v 1.6 2009/02/02 19:31:40 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/toasting.h,v 1.7 2009/05/07 22:58:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,7 +17,7 @@
 /*
  * toasting.c prototypes
  */
-extern void AlterTableCreateToastTable(Oid relOid, Datum reloptions);
+extern void AlterTableCreateToastTable(Oid relOid, Datum reloptions, bool force);
 extern void BootstrapToastTable(char *relName,
                                        Oid toastOid, Oid toastIndexOid);