Portal and memory management infrastructure for extended query protocol.

Both plannable queries and utility commands are now always executed
within Portals, which have been revamped so that they can handle the
load (they used to be good only for single SELECT queries).  Restructure
code to push command-completion-tag selection logic out of postgres.c,
so that it won't have to be duplicated between simple and extended queries.
initdb forced due to addition of a field to Query nodes.

Author: tglsfdc

contrib/intagg/int_aggregate.c

@@ -77,7 +77,9 @@ PG_FUNCTION_INFO_V1(int_enum);
 
 /*
  * Manage the aggregation state of the array
- * You need to specify the correct memory context, or it will vanish!
+ *
+ * Need to specify a suitably long-lived memory context, or it will vanish!
+ * PortalContext isn't really right, but it's close enough.
  */
 static PGARRAY *
 GetPGArray(int4 state, int fAdd)
@@ -89,14 +91,7 @@ GetPGArray(int4 state, int fAdd)
 		/* New array */
 		int			cb = PGARRAY_SIZE(START_NUM);
 
-		p = (PGARRAY *) MemoryContextAlloc(TopTransactionContext, cb);
-
-		if (!p)
-		{
-			elog(ERROR, "Integer aggregator, cant allocate TopTransactionContext memory");
-			return 0;
-		}
-
+		p = (PGARRAY *) MemoryContextAlloc(PortalContext, cb);
 		p->a.size = cb;
 		p->a.ndim = 0;
 		p->a.flags = 0;
@@ -115,18 +110,6 @@ GetPGArray(int4 state, int fAdd)
 			int			cbNew = PGARRAY_SIZE(n);
 
 			pn = (PGARRAY *) repalloc(p, cbNew);
-
-			if (!pn)
-			{					/* Realloc failed! Reallocate new block. */
-				pn = (PGARRAY *) MemoryContextAlloc(TopTransactionContext, cbNew);
-				if (!pn)
-				{
-					elog(ERROR, "Integer aggregator, REALLY REALLY can't alloc memory");
-					return (PGARRAY *) NULL;
-				}
-				memcpy(pn, p, p->a.size);
-				pfree(p);
-			}
 			pn->a.size = cbNew;
 			pn->lower = n;
 			return pn;
@@ -149,24 +132,19 @@ ShrinkPGArray(PGARRAY * p)
 
 		/* use current transaction context */
 		pnew = palloc(cb);
-
-		if (pnew)
-		{
-			/*
-			 * Fix up the fields in the new structure, so Postgres
-			 * understands
-			 */
-			memcpy(pnew, p, cb);
-			pnew->a.size = cb;
-			pnew->a.ndim = 1;
-			pnew->a.flags = 0;
+		/*
+		 * Fix up the fields in the new structure, so Postgres
+		 * understands
+		 */
+		memcpy(pnew, p, cb);
+		pnew->a.size = cb;
+		pnew->a.ndim = 1;
+		pnew->a.flags = 0;
 #ifndef PG_7_2
-			pnew->a.elemtype = INT4OID;
+		pnew->a.elemtype = INT4OID;
 #endif
-			pnew->lower = 0;
-		}
-		else
-			elog(ERROR, "Integer aggregator, can't allocate memory");
+		pnew->lower = 0;
+
 		pfree(p);
 	}
 	return pnew;

doc/src/sgml/ref/postgres-ref.sgml

@@ -1,5 +1,5 @@
 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/postgres-ref.sgml,v 1.32 2003/03/25 16:15:43 petere Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/postgres-ref.sgml,v 1.33 2003/05/02 20:54:33 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -28,7 +28,6 @@ PostgreSQL documentation
    <arg>-E</arg>
    <arg>-f<group choice="plain"><arg>s</arg><arg>i</arg><arg>t</arg><arg>n</arg><arg>m</arg><arg>h</arg></group></arg>
    <arg>-F</arg>
-   <arg>-i</arg>
    <arg>-N</arg>
    <arg>-o <replaceable>filename</replaceable></arg>
    <arg>-O</arg>
@@ -52,7 +51,6 @@ PostgreSQL documentation
    <arg>-e</arg>
    <arg>-f<group choice="plain"><arg>s</arg><arg>i</arg><arg>t</arg><arg>n</arg><arg>m</arg><arg>h</arg></group></arg>
    <arg>-F</arg>
-   <arg>-i</arg>
    <arg>-o <replaceable>filename</replaceable></arg>
    <arg>-O</arg>
    <arg>-p <replaceable>database</replaceable></arg>
@@ -281,15 +279,6 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
-     <varlistentry>
-      <term><option>-i</option></term>
-      <listitem>
-       <para>
-	Prevents query execution, but shows the plan tree.
-       </para>
-      </listitem>
-     </varlistentry>
-
      <varlistentry>
       <term><option>-O</option></term>
       <listitem>

src/backend/access/transam/xact.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.146 2003/04/26 20:22:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.147 2003/05/02 20:54:33 tgl Exp $
  *
  * NOTES
  *		Transaction aborts can now occur two ways:
@@ -49,7 +49,7 @@
  *		* CleanupTransaction() executes when we finally see a user COMMIT
  *		  or ROLLBACK command; it cleans things up and gets us out of
  *		  the transaction internally.  In particular, we mustn't destroy
- *		  TransactionCommandContext until this point.
+ *		  TopTransactionContext until this point.
  *
  *	 NOTES
  *		The essential aspects of the transaction system are:
@@ -456,13 +456,12 @@ static void
 AtStart_Memory(void)
 {
 	/*
-	 * We shouldn't have any transaction contexts already.
+	 * We shouldn't have a transaction context already.
 	 */
 	Assert(TopTransactionContext == NULL);
-	Assert(TransactionCommandContext == NULL);
 
 	/*
-	 * Create a toplevel context for the transaction.
+	 * Create a toplevel context for the transaction, and make it active.
 	 */
 	TopTransactionContext =
 		AllocSetContextCreate(TopMemoryContext,
@@ -471,16 +470,7 @@ AtStart_Memory(void)
 							  ALLOCSET_DEFAULT_INITSIZE,
 							  ALLOCSET_DEFAULT_MAXSIZE);
 
-	/*
-	 * Create a statement-level context and make it active.
-	 */
-	TransactionCommandContext =
-		AllocSetContextCreate(TopTransactionContext,
-							  "TransactionCommandContext",
-							  ALLOCSET_DEFAULT_MINSIZE,
-							  ALLOCSET_DEFAULT_INITSIZE,
-							  ALLOCSET_DEFAULT_MAXSIZE);
-	MemoryContextSwitchTo(TransactionCommandContext);
+	MemoryContextSwitchTo(TopTransactionContext);
 }
 
 
@@ -659,7 +649,6 @@ AtCommit_Memory(void)
 	Assert(TopTransactionContext != NULL);
 	MemoryContextDelete(TopTransactionContext);
 	TopTransactionContext = NULL;
-	TransactionCommandContext = NULL;
 }
 
 /* ----------------------------------------------------------------
@@ -769,19 +758,18 @@ AtAbort_Memory(void)
 {
 	/*
 	 * Make sure we are in a valid context (not a child of
-	 * TransactionCommandContext...).  Note that it is possible for this
+	 * TopTransactionContext...).  Note that it is possible for this
 	 * code to be called when we aren't in a transaction at all; go
 	 * directly to TopMemoryContext in that case.
 	 */
-	if (TransactionCommandContext != NULL)
+	if (TopTransactionContext != NULL)
 	{
-		MemoryContextSwitchTo(TransactionCommandContext);
+		MemoryContextSwitchTo(TopTransactionContext);
 
 		/*
-		 * We do not want to destroy transaction contexts yet, but it
-		 * should be OK to delete any command-local memory.
+		 * We do not want to destroy the transaction's global state yet,
+		 * so we can't free any memory here.
 		 */
-		MemoryContextResetAndDeleteChildren(TransactionCommandContext);
 	}
 	else
 		MemoryContextSwitchTo(TopMemoryContext);
@@ -812,7 +800,6 @@ AtCleanup_Memory(void)
 	if (TopTransactionContext != NULL)
 		MemoryContextDelete(TopTransactionContext);
 	TopTransactionContext = NULL;
-	TransactionCommandContext = NULL;
 }
 
 
@@ -926,7 +913,7 @@ CommitTransaction(void)
 	 * access, and in fact could still cause an error...)
 	 */
 
-	AtEOXact_portals(true);
+	AtCommit_Portals();
 
 	/* handle commit for large objects [ PA, 7/17/98 ] */
 	/* XXX probably this does not belong here */
@@ -1057,7 +1044,7 @@ AbortTransaction(void)
 	 * do abort processing
 	 */
 	DeferredTriggerAbortXact();
-	AtEOXact_portals(false);
+	AtAbort_Portals();
 	lo_commit(false);			/* 'false' means it's abort */
 	AtAbort_Notify();
 	AtEOXact_UpdatePasswordFile(false);
@@ -1126,7 +1113,8 @@ CleanupTransaction(void)
 	/*
 	 * do abort cleanup processing
 	 */
-	AtCleanup_Memory();
+	AtCleanup_Portals();		/* now safe to release portal memory */
+	AtCleanup_Memory();			/* and transaction memory */
 
 	/*
 	 * done with abort processing, set current transaction state back to
@@ -1220,11 +1208,11 @@ StartTransactionCommand(bool preventChain)
 	}
 
 	/*
-	 * We must switch to TransactionCommandContext before returning. This
+	 * We must switch to TopTransactionContext before returning. This
 	 * is already done if we called StartTransaction, otherwise not.
 	 */
-	Assert(TransactionCommandContext != NULL);
-	MemoryContextSwitchTo(TransactionCommandContext);
+	Assert(TopTransactionContext != NULL);
+	MemoryContextSwitchTo(TopTransactionContext);
 }
 
 /*
@@ -1266,7 +1254,6 @@ CommitTransactionCommand(bool forceCommit)
 				Assert(s->blockState == TBLOCK_INPROGRESS);
 				/* This code must match the TBLOCK_INPROGRESS case below: */
 				CommandCounterIncrement();
-				MemoryContextResetAndDeleteChildren(TransactionCommandContext);
 			}
 			break;
 
@@ -1283,15 +1270,10 @@ CommitTransactionCommand(bool forceCommit)
 			/*
 			 * This is the case when we have finished executing a command
 			 * someplace within a transaction block.  We increment the
-			 * command counter and return.	Someday we may free resources
-			 * local to the command.
-			 *
-			 * That someday is today, at least for memory allocated in
-			 * TransactionCommandContext. - vadim 03/25/97
+			 * command counter and return.
 			 */
 		case TBLOCK_INPROGRESS:
 			CommandCounterIncrement();
-			MemoryContextResetAndDeleteChildren(TransactionCommandContext);
 			break;
 
 			/*

src/backend/commands/cluster.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.107 2003/03/20 03:34:55 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.108 2003/05/02 20:54:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -189,10 +189,10 @@ cluster(ClusterStmt *stmt)
 		/*
 		 * Create special memory context for cross-transaction storage.
 		 *
-		 * Since it is a child of QueryContext, it will go away even in case
+		 * Since it is a child of PortalContext, it will go away even in case
 		 * of error.
 		 */
-		cluster_context = AllocSetContextCreate(QueryContext,
+		cluster_context = AllocSetContextCreate(PortalContext,
 												"Cluster",
 												ALLOCSET_DEFAULT_MINSIZE,
 												ALLOCSET_DEFAULT_INITSIZE,

src/backend/commands/indexcmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.97 2003/01/23 15:18:40 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.98 2003/05/02 20:54:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -720,11 +720,11 @@ ReindexDatabase(const char *dbname, bool force, bool all)
 
 	/*
 	 * Create a memory context that will survive forced transaction
-	 * commits we do below.  Since it is a child of QueryContext, it will
+	 * commits we do below.  Since it is a child of PortalContext, it will
 	 * go away eventually even if we suffer an error; there's no need for
 	 * special abort cleanup logic.
 	 */
-	private_context = AllocSetContextCreate(QueryContext,
+	private_context = AllocSetContextCreate(PortalContext,
 											"ReindexDatabase",
 											ALLOCSET_DEFAULT_MINSIZE,
 											ALLOCSET_DEFAULT_INITSIZE,