Portal integration changes.

This integrates Postgres-XC code deeper into PostgreSQL.
The Extended Query Protocol can now be used, which means that
JDBC will now work. It also lays more groundwork for
supporting multi-step queries (cross-node joins).

Note that statements with parameters cannot yet
be prepared and executed, only those without parameters
will work.

Note also that this patch introduces additional performance
degradation because more processing occurs with
each request. We will be working to address these
issues in the coming weeks.

Written by Andrei Martsinchyk

1 files changed, 28 insertions, 226 deletions

diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index e59c86920e..5aa9e5d97a 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -650,6 +650,20 @@ pg_analyze_and_rewrite(Node *parsetree, const char *query_string,
 	 */
 	querytree_list = pg_rewrite_query(query);
 
+#ifdef PGXC
+	if (IS_PGXC_COORDINATOR)
+	{
+		ListCell   *lc;
+
+		foreach(lc, querytree_list)
+		{
+			Query *query = (Query *) lfirst(lc);
+			query->sql_statement = pstrdup(query_string);
+			query->nodeTag = nodeTag(parsetree);
+		}
+	}
+#endif
+
 	TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
 
 	return querytree_list;
@@ -900,9 +914,6 @@ exec_simple_query(const char *query_string)
 		DestReceiver *receiver;
 		int16		format;
 #ifdef PGXC
-		Query_Plan *query_plan;
-		RemoteQuery *query_step;
-		bool 		exec_on_coord;
 
 		/*
 		 * By default we do not want data nodes to contact GTM directly,
@@ -910,9 +921,6 @@ exec_simple_query(const char *query_string)
 		 */
 		if (IS_PGXC_DATANODE)
 			SetForceXidFromGTM(false);
-
-		exec_on_coord = true;
-		query_plan = NULL;
 #endif
 
 		/*
@@ -968,131 +976,11 @@ exec_simple_query(const char *query_string)
 		querytree_list = pg_analyze_and_rewrite(parsetree, query_string,
 												NULL, 0);
 
-#ifdef PGXC /* PGXC_COORD */
-		if (IS_PGXC_COORDINATOR)
-		{
-			if (IsA(parsetree, TransactionStmt))
-				pgxc_transaction_stmt(parsetree);
-
-			else if (IsA(parsetree, ExecDirectStmt))
-			{
-				ExecDirectStmt *execdirect = (ExecDirectStmt *) parsetree;
-				List *inner_parse_tree_list;
-
-				Assert(IS_PGXC_COORDINATOR);
-
-				exec_on_coord = execdirect->coordinator;
-
-				/*
-				 * Switch to appropriate context for constructing parse and
-				 * query trees (these must outlive the execution context).
-				 */
-				oldcontext = MemoryContextSwitchTo(MessageContext);
-
-				inner_parse_tree_list = pg_parse_query(execdirect->query);
-				/*
-				 * we do not support complex commands (expanded to multiple
-				 * parse trees) within EXEC DIRECT
-				 */
-				if (list_length(parsetree_list) != 1)
-				{
-					ereport(ERROR,
-						   (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-							errmsg("Can not execute %s with EXECUTE DIRECT",
-								execdirect->query)));
-				}
-				parsetree = linitial(inner_parse_tree_list);
-
-				/*
-				 * Set up a snapshot if parse analysis/planning will need
-				 * one.
-				 */
-				if (analyze_requires_snapshot(parsetree))
-				{
-					PushActiveSnapshot(GetTransactionSnapshot());
-					snapshot_set = true;
-				}
-
-				querytree_list = pg_analyze_and_rewrite(parsetree,
-														query_string,
-														NULL,
-														0);
-
-				if (execdirect->nodes)
-				{
-					ListCell   *lc;
-					Query	   *query = (Query *) linitial(querytree_list);
-
-					query_plan = (Query_Plan *) palloc0(sizeof(Query_Plan));
-					query_step = makeNode(RemoteQuery);
-					query_step->plan.targetlist = query->targetList;
-					query_step->sql_statement = pstrdup(execdirect->query);
-					query_step->exec_nodes = (Exec_Nodes *) palloc0(sizeof(Exec_Nodes));
-					foreach (lc, execdirect->nodes)
-					{
-						int node = intVal(lfirst(lc));
-						query_step->exec_nodes->nodelist = lappend_int(query_step->exec_nodes->nodelist, node);
-					}
-					query_step->combine_type = COMBINE_TYPE_SAME;
-
-					query_plan->query_step_list = lappend(NULL, query_step);
-					query_plan->exec_loc_type = EXEC_ON_DATA_NODES;
-				}
-
-				/* Restore context */
-				MemoryContextSwitchTo(oldcontext);
-
-			}
-			else if (IsA(parsetree, CopyStmt))
-			{
-				CopyStmt   *copy = (CopyStmt *) parsetree;
-				uint64		processed;
-				/* Snapshot is needed for the Copy */
-				if (!snapshot_set)
-				{
-					PushActiveSnapshot(GetTransactionSnapshot());
-					snapshot_set = true;
-				}
-				/*
-				 * A check on locator is made in DoCopy to determine if the copy can be launched on
-				 * Datanode or on Coordinator.
-				 * If a table has no locator data, then IsCoordPortalCopy returns false and copy is launched
-				 * on Coordinator instead (e.g., using pg_catalog tables).
-				 * If a table has some locator data (user tables), then copy was launched normally
-				 * in Datanodes
-				 */
-				if (!IsCoordPortalCopy(copy))
-				{
-					exec_on_coord = false;
-					processed = DoCopy(copy, query_string, false);
-					snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
-							 "COPY " UINT64_FORMAT, processed);
-				}
-				else
-					exec_on_coord = true;
-			}
-			else
-			{
-				query_plan = GetQueryPlan(parsetree, query_string, querytree_list);
-
-				exec_on_coord = query_plan->exec_loc_type & EXEC_ON_COORD;
-			}
-
-			/* First execute on the coordinator, if involved (DDL),  then data nodes */
-		}
-
-		plantree_list = NIL;
-		if ((IS_PGXC_COORDINATOR && exec_on_coord) || IS_PGXC_DATANODE)
-#endif
-			plantree_list = pg_plan_queries(querytree_list, 0, NULL);
+		plantree_list = pg_plan_queries(querytree_list, 0, NULL);
 
 		/* Done with the snapshot used for parsing/planning */
-#ifdef PGXC
-		/* In PG-XC, hold on to it a bit longer */
-#else
 		if (snapshot_set)
 			PopActiveSnapshot();
-#endif
 
 		/* If we got a cancel signal in analysis or planning, quit */
 		CHECK_FOR_INTERRUPTS();
@@ -1102,13 +990,6 @@ exec_simple_query(const char *query_string)
 		/* Force getting Xid from GTM if not autovacuum, but a vacuum */
 		if (IS_PGXC_DATANODE && IsA(parsetree, VacuumStmt) && IsPostmasterEnvironment)
 			SetForceXidFromGTM(true);
-
-		/*
-		 * Create and run Portal only if it is needed.
-		 * In some special cases we have nothing to run at this point
-		 */
-		if (plantree_list || query_plan)
-		{
 #endif
 
 		/*
@@ -1170,11 +1051,6 @@ exec_simple_query(const char *query_string)
 		 */
 		MemoryContextSwitchTo(oldcontext);
 
-#ifdef PGXC
-		/* Skip the Portal stuff on coordinator if command only executes on data nodes */
-		if ((IS_PGXC_COORDINATOR && exec_on_coord) || IS_PGXC_DATANODE)
-		{
-#endif
 		/*
 		 * Run the portal to completion, and then drop it (and the receiver).
 		 */
@@ -1185,55 +1061,10 @@ exec_simple_query(const char *query_string)
 						 receiver,
 						 completionTag);
 
-#ifdef PGXC
-		}
-
-		/* PGXC_COORD */
-		/* If the coordinator ran ok, now run on the data nodes if planned */
-		if (IS_PGXC_COORDINATOR)
-		{
-			if (query_plan && (query_plan->exec_loc_type & EXEC_ON_DATA_NODES))
-			{
-				RemoteQueryState *state;
-				TupleTableSlot *slot;
-				EState *estate = CreateExecutorState();
-				oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
-				query_step = linitial(query_plan->query_step_list);
-				estate->es_tupleTable = ExecCreateTupleTable(2);
-				state = ExecInitRemoteQuery(query_step, estate, 0);
-				state->dest = receiver;
-				state->completionTag = completionTag;
-				if (!snapshot_set)
-				{
-					PushActiveSnapshot(GetTransactionSnapshot());
-					snapshot_set = true;
-				}
-				do
-				{
-					slot = ExecRemoteQuery(state);
-				}
-				while (!TupIsNull(slot));
-
-				ExecEndRemoteQuery(state);
-				/* Restore context */
-				MemoryContextSwitchTo(oldcontext);
-			}
-
-			FreeQueryPlan(query_plan);
-		}
-#endif /* PGXC_COORD */
-
 		(*receiver->rDestroy) (receiver);
 
 		PortalDrop(portal, false);
 
-#ifdef PGXC
-		}
-
-		if (snapshot_set)
-			PopActiveSnapshot();
-#endif
-
 		if (IsA(parsetree, TransactionStmt))
 		{
 			/*
@@ -1479,6 +1310,19 @@ exec_parse_message(const char *query_string,	/* string to execute */
 			ShowUsage("PARSE ANALYSIS STATISTICS");
 
 		querytree_list = pg_rewrite_query(query);
+#ifdef PGXC
+		if (IS_PGXC_COORDINATOR)
+		{
+			ListCell   *lc;
+
+			foreach(lc, querytree_list)
+			{
+				Query *query = (Query *) lfirst(lc);
+				query->sql_statement = pstrdup(query_string);
+				query->nodeTag = nodeTag(raw_parse_tree);
+			}
+		}
+#endif
 
 		/*
 		 * If this is the unnamed statement and it has parameters, defer query
@@ -4365,45 +4209,3 @@ log_disconnections(int code, Datum arg)
 					port->user_name, port->database_name, port->remote_host,
 				  port->remote_port[0] ? " port=" : "", port->remote_port)));
 }
-
-
-#ifdef PGXC
-/*
- * Handle transaction statements in PG-XC
- */
-void
-pgxc_transaction_stmt (Node *parsetree)
-{
-	Assert(IS_PGXC_COORDINATOR);
-
-
-	/* Handle transaction statements specially */
-	if (IsA(parsetree, TransactionStmt))
-	{
-			TransactionStmt *stmt = (TransactionStmt *) parsetree;
-
-			switch (stmt->kind)
-			{
-				case TRANS_STMT_BEGIN:
-					/*
-					 * This does not yet send down a BEGIN,
-					 * we do that "on demand" as data nodes are added
-					 */
-					DataNodeBegin();
-				break;
-
-				case TRANS_STMT_COMMIT:
-					DataNodeCommit();
-					break;
-
-				case TRANS_STMT_ROLLBACK:
-					DataNodeRollback();
-					break;
-
-				default:
-					/* Ignore others for prototype */
-					break;
-			}
-	}
-}
-#endif /* PGXC */