Fix places that were using IsTransactionBlock() as an (inadequate) check

that they'd get to commit immediately on finishing.  There's now a
centralized routine PreventTransactionChain() that implements the
necessary tests.

4 files changed, 41 insertions, 38 deletions

diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index addb6dcae4e..327aac29593 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.105 2002/09/04 20:31:15 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.106 2002/10/21 22:06:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -152,8 +152,7 @@ createdb(const CreatedbStmt *stmt)
 	}
 
 	/* don't call this in a transaction block */
-	if (IsTransactionBlock())
-		elog(ERROR, "CREATE DATABASE: may not be called in a transaction block");
+	PreventTransactionChain((void *) stmt, "CREATE DATABASE");
 
 	/*
 	 * Check for db name conflict.	There is a race condition here, since
@@ -382,8 +381,7 @@ dropdb(const char *dbname)
 	if (strcmp(dbname, DatabaseName) == 0)
 		elog(ERROR, "DROP DATABASE: cannot be executed on the currently open database");
 
-	if (IsTransactionBlock())
-		elog(ERROR, "DROP DATABASE: may not be called in a transaction block");
+	PreventTransactionChain((void *) dbname, "DROP DATABASE");
 
 	/*
 	 * Obtain exclusive lock on pg_database.  We need this to ensure that
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 43aec83ce32..5447780b69e 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.91 2002/10/19 20:15:08 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.92 2002/10/21 22:06:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -560,15 +560,10 @@ ReindexIndex(RangeVar *indexRelation, bool force /* currently unused */ )
 {
 	Oid			indOid;
 	HeapTuple	tuple;
-	bool		overwrite = false;
+	bool		overwrite;
 
-	/*
-	 * REINDEX within a transaction block is dangerous, because if the
-	 * transaction is later rolled back we have no way to undo truncation
-	 * of the index's physical file.  Disallow it.
-	 */
-	if (IsTransactionBlock())
-		elog(ERROR, "REINDEX cannot run inside a BEGIN/END block");
+	/* Choose in-place-or-not mode */
+	overwrite = IsIgnoringSystemIndexes();
 
 	indOid = RangeVarGetRelid(indexRelation, false);
 	tuple = SearchSysCache(RELOID,
@@ -595,8 +590,14 @@ ReindexIndex(RangeVar *indexRelation, bool force /* currently unused */ )
 
 	ReleaseSysCache(tuple);
 
-	if (IsIgnoringSystemIndexes())
-		overwrite = true;
+	/*
+	 * In-place REINDEX within a transaction block is dangerous, because
+	 * if the transaction is later rolled back we have no way to undo
+	 * truncation of the index's physical file.  Disallow it.
+	 */
+	if (overwrite)
+		PreventTransactionChain((void *) indexRelation, "REINDEX");
+
 	if (!reindex_index(indOid, force, overwrite))
 		elog(WARNING, "index \"%s\" wasn't reindexed", indexRelation->relname);
 }
@@ -611,14 +612,6 @@ ReindexTable(RangeVar *relation, bool force)
 	Oid			heapOid;
 	char		relkind;
 
-	/*
-	 * REINDEX within a transaction block is dangerous, because if the
-	 * transaction is later rolled back we have no way to undo truncation
-	 * of the index's physical file.  Disallow it.
-	 */
-	if (IsTransactionBlock())
-		elog(ERROR, "REINDEX cannot run inside a BEGIN/END block");
-
 	heapOid = RangeVarGetRelid(relation, false);
 	relkind = get_rel_relkind(heapOid);
 
@@ -626,6 +619,17 @@ ReindexTable(RangeVar *relation, bool force)
 		elog(ERROR, "relation \"%s\" is of type \"%c\"",
 			 relation->relname, relkind);
 
+	/*
+	 * In-place REINDEX within a transaction block is dangerous, because
+	 * if the transaction is later rolled back we have no way to undo
+	 * truncation of the index's physical file.  Disallow it.
+	 *
+	 * XXX we assume that in-place reindex will only be done if
+	 * IsIgnoringSystemIndexes() is true.
+	 */
+	if (IsIgnoringSystemIndexes())
+		PreventTransactionChain((void *) relation, "REINDEX");
+
 	if (!reindex_relation(heapOid, force))
 		elog(WARNING, "table \"%s\" wasn't reindexed", relation->relname);
 }
@@ -666,12 +670,7 @@ ReindexDatabase(const char *dbname, bool force, bool all)
 	 * transaction, then our commit- and start-transaction-command calls
 	 * would not have the intended effect!
 	 */
-	if (IsTransactionBlock())
-		elog(ERROR, "REINDEX DATABASE cannot run inside a BEGIN/END block");
-
-	/* Running this from a function would free the function context */
-	if (!MemoryContextContains(QueryContext, (void *) dbname))
-		elog(ERROR, "REINDEX DATABASE cannot be executed from a function");
+	PreventTransactionChain((void *) dbname, "REINDEX");
 
 	/*
 	 * Create a memory context that will survive forced transaction
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ae15b815332..f211448f413 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.49 2002/10/21 20:31:51 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.50 2002/10/21 22:06:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -376,6 +376,16 @@ TruncateRelation(const RangeVar *relation)
 		aclcheck_error(ACLCHECK_NOT_OWNER, RelationGetRelationName(rel));
 
 	/*
+	 * Truncate within a transaction block is dangerous, because if
+	 * the transaction is later rolled back we have no way to undo
+	 * truncation of the relation's physical file.  Disallow it except for
+	 * a rel created in the current xact (which would be deleted on abort,
+	 * anyway).
+	 */
+	if (!rel->rd_isnew)
+		PreventTransactionChain((void *) relation, "TRUNCATE TABLE");
+
+	/*
 	 * Don't allow truncate on temp tables of other backends ... their
 	 * local buffer manager is not going to cope.
 	 */
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 2ff3aae6f8a..160289c91e0 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.242 2002/10/19 20:15:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.243 2002/10/21 22:06:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -177,12 +177,8 @@ vacuum(VacuumStmt *vacstmt)
 	 * user's transaction too, which would certainly not be the desired
 	 * behavior.
 	 */
-	if (vacstmt->vacuum && IsTransactionBlock())
-		elog(ERROR, "%s cannot run inside a BEGIN/END block", stmttype);
-
-	/* Running VACUUM from a function would free the function context */
-	if (vacstmt->vacuum && !MemoryContextContains(QueryContext, vacstmt))
-		elog(ERROR, "%s cannot be executed from a function", stmttype);
+	if (vacstmt->vacuum)
+		PreventTransactionChain((void *) vacstmt, stmttype);
 
 	/*
 	 * Send info about dead objects to the statistics collector