From 4299a670da066b83a70dd074a9d66dc9c77cbc71 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 8 Mar 2017 10:39:26 +0530
Subject: [PATCH 1/2] Support SUMMARY option in EXPLAIN output.

Add SUMMARY option to EXPLAIN output to print "summary" of the query.
Right now the summary will include planning time and execution time,
the later being available when ANALYZE is requested.

This patch exposes an internal switch "summary" in ExplainState as an
option to EXPLAIN command.
---
 doc/src/sgml/ref/explain.sgml  |   13 +++++++++++++
 src/backend/commands/explain.c |   17 ++++++++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index f14a58d..4d83359 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -41,6 +41,7 @@ EXPLAIN [ ANALYZE ] [ VERBOSE ] <replaceable class="parameter">statement</replac
     COSTS [ <replaceable class="parameter">boolean</replaceable> ]
     BUFFERS [ <replaceable class="parameter">boolean</replaceable> ]
     TIMING [ <replaceable class="parameter">boolean</replaceable> ]
+    SUMMARY [ <replaceable class="parameter">boolean</replaceable> ]
     FORMAT { TEXT | XML | JSON | YAML }
 </synopsis>
  </refsynopsisdiv>
@@ -197,6 +198,18 @@ ROLLBACK;
    </varlistentry>
 
    <varlistentry>
+    <term><literal>SUMMARY</literal></term>
+    <listitem>
+     <para>
+      Include planning time and execution time. Execution time is included
+      when <literal>ANALYZE</literal> is enabled.
+      It defaults to <literal>TRUE</literal> when <literal>ANALYZE</literal>
+      is enabled. Otherwise it defaults to <literal>FALSE</literal>.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
     <term><literal>FORMAT</literal></term>
     <listitem>
      <para>
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index c9e0a3e..bd0fb20 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -149,6 +149,7 @@ ExplainQuery(ParseState *pstate, ExplainStmt *stmt, const char *queryString,
 	List	   *rewritten;
 	ListCell   *lc;
 	bool		timing_set = false;
+	bool		summary_set = false;
 
 	/* Parse options list. */
 	foreach(lc, stmt->options)
@@ -168,6 +169,11 @@ ExplainQuery(ParseState *pstate, ExplainStmt *stmt, const char *queryString,
 			timing_set = true;
 			es->timing = defGetBoolean(opt);
 		}
+		else if (strcmp(opt->defname, "summary") == 0)
+		{
+			summary_set = true;
+			es->summary = defGetBoolean(opt);
+		}
 		else if (strcmp(opt->defname, "format") == 0)
 		{
 			char	   *p = defGetString(opt);
@@ -209,8 +215,8 @@ ExplainQuery(ParseState *pstate, ExplainStmt *stmt, const char *queryString,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("EXPLAIN option TIMING requires ANALYZE")));
 
-	/* currently, summary option is not exposed to users; just set it */
-	es->summary = es->analyze;
+	/* if the summary was not set explicitly, set default value */
+	es->summary = (summary_set) ? es->summary : es->analyze;
 
 	/*
 	 * Parse analysis was done already, but we still have to run the rule
@@ -571,7 +577,12 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
 
 	totaltime += elapsed_time(&starttime);
 
-	if (es->summary)
+	/*
+	 * Execution time matters only when analyze is requested. If user has
+	 * explicitly requested not to report summary, don't report total execution
+	 * time.
+	 */
+	if (es->summary && es->analyze)
 	{
 		if (es->format == EXPLAIN_FORMAT_TEXT)
 			appendStringInfo(es->str, "Execution time: %.3f ms\n",
-- 
1.7.9.5