The patch does 2 things:

[postgresql] / src / backend / commands / explain.c

diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 63534050f1c081aaa871046bc77dfe5f619b089b..1b861c96204944ccb93fc8cbb986c2fffff8d21e 100644 (file)
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.24 1998/09/01 04:27:53 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.25 1998/10/21 16:21:20 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -26,6 +26,7 @@
 #include <optimizer/planner.h>
 #include <access/xact.h>
 #include <utils/relcache.h>
+#include <rewrite/rewriteHandler.h>
 
 typedef struct ExplainState
 {
@@ -37,6 +38,8 @@ typedef struct ExplainState
 } ExplainState;
 
 static char *Explain_PlanToString(Plan *plan, ExplainState *es);
+static void ExplainOneQuery(Query *query, bool verbose, CommandDest dest);
+
 
 /*
  * ExplainQuery -
@@ -46,11 +49,8 @@ static char *Explain_PlanToString(Plan *plan, ExplainState *es);
 void
 ExplainQuery(Query *query, bool verbose, CommandDest dest)
 {
-       char       *s = NULL,
-                          *s2;
-       Plan       *plan;
-       ExplainState *es;
-       int                     len;
+       List    *rewritten;
+       List    *l;
 
        if (IsAbortedTransactionBlockState())
        {
@@ -64,6 +64,35 @@ ExplainQuery(Query *query, bool verbose, CommandDest dest)
                return;
        }
 
+       /* Rewrite through rule system */
+       rewritten = QueryRewrite(query);
+
+       /* In the case of an INSTEAD NOTHING, tell at least that */
+       if (rewritten == NIL)
+       {
+               elog(NOTICE, "query rewrites to nothing");
+               return;
+       }
+
+       /* Explain every plan */
+       foreach(l, rewritten)
+               ExplainOneQuery(lfirst(l), verbose, dest);
+}
+
+/*
+ * ExplainOneQuery -
+ *       print out the execution plan for one query
+ *
+ */
+static void
+ExplainOneQuery(Query *query, bool verbose, CommandDest dest)
+{
+       char       *s = NULL,
+                          *s2;
+       Plan       *plan;
+       ExplainState *es;
+       int                     len;
+
        /* plan the queries (XXX we've ignored rewrite!!) */
        plan = planner(query);
 
@@ -202,8 +231,13 @@ explain_outNode(StringInfo str, Plan *plan, int indent, ExplainState *es)
                        {
                                RangeTblEntry *rte = nth(((Scan *) plan)->scanrelid - 1, es->rtable);
 
-                               sprintf(buf, " on %s", rte->refname);
-                               appendStringInfo(str, buf);
+                               appendStringInfo(str, " on ");
+                               if (strcmp(rte->refname, rte->relname) != 0)
+                               {
+                                       sprintf(buf, "%s ", rte->relname);
+                                       appendStringInfo(str, buf);
+                               }
+                               appendStringInfo(str, rte->refname);
                        }
                        break;
                default:
@@ -232,7 +266,7 @@ explain_outNode(StringInfo str, Plan *plan, int indent, ExplainState *es)
                        for (i = 0; i < indent; i++)
                                appendStringInfo(str, "  ");
                        appendStringInfo(str, "    ->  ");
-                       explain_outNode(str, ((SubPlan *) lfirst(lst))->plan, indent + 4, es);
+                       explain_outNode(str, ((SubPlan *) lfirst(lst))->plan, indent + 2, es);
                }
                es->rtable = saved_rtable;
        }