Add display of sort keys to the default EXPLAIN output.

diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index cb2b2d0f23e3a8b820f2d7053a9bd62fefd57acd..a7412b0e7204e2c980f3131e302e145fd126e8df 100644 (file)
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -5,7 +5,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994-5, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.77 2002/05/12 20:10:02 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.78 2002/05/18 21:38:40 tgl Exp $
  *
  */
 
@@ -56,6 +56,8 @@ static void show_upper_qual(List *qual, const char *qlabel,
                                                        const char *outer_name, int outer_varno, Plan *outer_plan,
                                                        const char *inner_name, int inner_varno, Plan *inner_plan,
                                                        StringInfo str, int indent, ExplainState *es);
+static void show_sort_keys(List *tlist, int nkeys, const char *qlabel,
+                                                  StringInfo str, int indent, ExplainState *es);
 static Node *make_ors_ands_explicit(List *orclauses);
 static TextOutputState *begin_text_output(CommandDest dest, char *title);
 static void do_text_output(TextOutputState *tstate, char *aline);
@@ -410,7 +412,7 @@ explain_outNode(StringInfo str, Plan *plan, Plan *outer_plan,
        }
        appendStringInfo(str, "\n");
 
-       /* quals */
+       /* quals, sort keys, etc */
        switch (nodeTag(plan))
        {
                case T_IndexScan:
@@ -495,6 +497,11 @@ explain_outNode(StringInfo str, Plan *plan, Plan *outer_plan,
                                                        "", 0, NULL,
                                                        str, indent, es);
                        break;
+               case T_Sort:
+                       show_sort_keys(plan->targetlist, ((Sort *) plan)->keycount,
+                                                  "Sort Key",
+                                                  str, indent, es);
+                       break;
                case T_Result:
                        show_upper_qual((List *) ((Result *) plan)->resconstantqual,
                                                        "One-Time Filter",
@@ -731,6 +738,60 @@ show_upper_qual(List *qual, const char *qlabel,
        appendStringInfo(str, "  %s: %s\n", qlabel, exprstr);
 }
 
+/*
+ * Show the sort keys for a Sort node.
+ */
+static void
+show_sort_keys(List *tlist, int nkeys, const char *qlabel,
+                          StringInfo str, int indent, ExplainState *es)
+{
+       List       *context;
+       bool            useprefix;
+       int                     keyno;
+       List       *tl;
+       char       *exprstr;
+       int                     i;
+
+       if (nkeys <= 0)
+               return;
+
+       for (i = 0; i < indent; i++)
+               appendStringInfo(str, "  ");
+       appendStringInfo(str, "  %s: ", qlabel);
+
+       /*
+        * In this routine we expect that the plan node's tlist has not been
+        * processed by set_plan_references(), so any Vars will contain valid
+        * varnos referencing the actual rtable.
+        */
+       context = deparse_context_from_rtable(es->rtable);
+       useprefix = length(es->rtable) > 1;
+
+       for (keyno = 1; keyno <= nkeys; keyno++)
+       {
+               /* find key expression in tlist */
+               foreach(tl, tlist)
+               {
+                       TargetEntry *target = (TargetEntry *) lfirst(tl);
+
+                       if (target->resdom->reskey == keyno)
+                       {
+                               /* Deparse the expression */
+                               exprstr = deparse_expression(target->expr, context, useprefix);
+                               /* And add to str */
+                               if (keyno > 1)
+                                       appendStringInfo(str, ", ");
+                               appendStringInfo(str, "%s", exprstr);
+                               break;
+                       }
+               }
+               if (tl == NIL)
+                       elog(ERROR, "show_sort_keys: no tlist entry for key %d", keyno);
+       }
+
+       appendStringInfo(str, "\n");
+}
+
 /*
  * Indexscan qual lists have an implicit OR-of-ANDs structure.  Make it
  * explicit so deparsing works properly.

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 88528b9a0652745749fb13f7023820534bd68ecf..738efdb74429667cda9d69205765b4809cebdbb9 100644 (file)
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -3,7 +3,7 @@
  *                             back to source text
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.105 2002/05/17 01:19:18 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.106 2002/05/18 21:38:40 tgl Exp $
  *
  *       This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -779,6 +779,27 @@ deparse_context_for_subplan(const char *name, List *tlist,
        return (Node *) rte;
 }
 
+/*
+ * deparse_context_from_rtable - Build deparse context given a rangetable
+ *
+ * This is suitable for deparsing expressions that refer to only a single
+ * level of variables (no outer-reference Vars).
+ */
+List *
+deparse_context_from_rtable(List *rtable)
+{
+       deparse_namespace *dpns;
+
+       dpns = (deparse_namespace *) palloc(sizeof(deparse_namespace));
+
+       dpns->rtable = rtable;
+       dpns->outer_varno = dpns->inner_varno = 0;
+       dpns->outer_rte = dpns->inner_rte = NULL;
+
+       /* Return a one-deep namespace stack */
+       return makeList1(dpns);
+}
+
 /* ----------
  * make_ruledef                        - reconstruct the CREATE RULE command
  *                               for a given pg_rewrite tuple

diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 7a8d1fb387312603b6be5d9e6b0b74278fafc86c..6340aa225403f402a3f65cdecca525f5f20e46b4 100644 (file)
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: builtins.h,v 1.181 2002/05/12 20:10:05 tgl Exp $
+ * $Id: builtins.h,v 1.182 2002/05/18 21:38:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -357,6 +357,7 @@ extern List *deparse_context_for_plan(int outer_varno, Node *outercontext,
 extern Node *deparse_context_for_rte(RangeTblEntry *rte);
 extern Node *deparse_context_for_subplan(const char *name, List *tlist,
                                                                                 List *rtable);
+extern List *deparse_context_from_rtable(List *rtable);
 extern const char *quote_identifier(const char *ident);
 extern char *quote_qualified_identifier(const char *namespace,
                                                                                const char *ident);