explain-analyze-rows-only-v3.diff

diff --git a/contrib/auto_explain/auto_explain.c b/contrib/auto_explain/auto_explain.c
index 61da6a2..9fc0ae1 100644
--- a/contrib/auto_explain/auto_explain.c
+++ b/contrib/auto_explain/auto_explain.c
@@ -23,6 +23,7 @@ static int	auto_explain_log_min_duration = -1; /* msec or -1 */
 static bool auto_explain_log_analyze = false;
 static bool auto_explain_log_verbose = false;
 static bool auto_explain_log_buffers = false;
+static bool auto_explain_log_timing  = false;
 static int	auto_explain_log_format = EXPLAIN_FORMAT_TEXT;
 static bool auto_explain_log_nested_statements = false;
 
@@ -133,6 +134,17 @@ _PG_init(void)
 							 NULL,
 							 NULL);
 
+	DefineCustomBoolVariable("auto_explain.log_timing",
+							 "Collect timing data, not just row counts.",
+							 NULL,
+							 &auto_explain_log_timing,
+							 true,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
 	EmitWarningsOnPlaceholders("auto_explain");
 
 	/* Install hooks. */
@@ -170,7 +182,12 @@ explain_ExecutorStart(QueryDesc *queryDesc, int eflags)
 		/* Enable per-node instrumentation iff log_analyze is required. */
 		if (auto_explain_log_analyze && (eflags & EXEC_FLAG_EXPLAIN_ONLY) == 0)
 		{
-			queryDesc->instrument_options |= INSTRUMENT_TIMER;
+			if (auto_explain_log_timing)
+				queryDesc->instrument_options |= INSTRUMENT_TIMER;
+			else
+				queryDesc->instrument_options |= INSTRUMENT_ROWS;
+
+
 			if (auto_explain_log_buffers)
 				queryDesc->instrument_options |= INSTRUMENT_BUFFERS;
 		}
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index 8a9c9de..4488956 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -40,6 +40,7 @@ EXPLAIN [ ANALYZE ] [ VERBOSE ] <replaceable class="parameter">statement</replac
     VERBOSE [ <replaceable class="parameter">boolean</replaceable> ]
     COSTS [ <replaceable class="parameter">boolean</replaceable> ]
     BUFFERS [ <replaceable class="parameter">boolean</replaceable> ]
+    TIMING [ <replaceable class="parameter">boolean</replaceable> ]
     FORMAT { TEXT | XML | JSON | YAML }
 </synopsis>
  </refsynopsisdiv>
@@ -172,6 +173,20 @@ ROLLBACK;
    </varlistentry>
 
    <varlistentry>
+    <term><literal>TIMING</literal></term>
+    <listitem>
+     <para>
+      Include information on timing for each node. Specifically, include the
+      actual startup time and time spent in the node. This may involve a lot
+      of gettimeofday calls, and on some systems this means significant
+      slowdown of the query. 
+      This parameter may only be used when <literal>ANALYZE</literal> is also
+      enabled.  It defaults to <literal>TRUE</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 8b48105..8251908 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -116,6 +116,7 @@ ExplainQuery(ExplainStmt *stmt, const char *queryString,
 	TupOutputState *tstate;
 	List	   *rewritten;
 	ListCell   *lc;
+	bool	    timing_set = false;
 
 	/* Initialize ExplainState. */
 	ExplainInitState(&es);
@@ -133,6 +134,11 @@ ExplainQuery(ExplainStmt *stmt, const char *queryString,
 			es.costs = defGetBoolean(opt);
 		else if (strcmp(opt->defname, "buffers") == 0)
 			es.buffers = defGetBoolean(opt);
+		else if (strcmp(opt->defname, "timing") == 0)
+		{
+			timing_set = true;
+			es.timing = defGetBoolean(opt);
+		}
 		else if (strcmp(opt->defname, "format") == 0)
 		{
 			char	   *p = defGetString(opt);
@@ -162,6 +168,15 @@ ExplainQuery(ExplainStmt *stmt, const char *queryString,
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("EXPLAIN option BUFFERS requires ANALYZE")));
+	
+	/* if the timing was not set explicitly, set default value */
+	es.timing = (timing_set) ? es.timing : es.analyze;
+
+	/* check that timing is used with EXPLAIN ANALYZE */
+	if (es.timing && !es.analyze)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("EXPLAIN option TIMING requires ANALYZE")));
 
 	/*
 	 * Parse analysis was done already, but we still have to run the rule
@@ -355,8 +370,11 @@ ExplainOnePlan(PlannedStmt *plannedstmt, ExplainState *es,
 	int			eflags;
 	int			instrument_option = 0;
 
-	if (es->analyze)
+	if (es->analyze && es->timing)
 		instrument_option |= INSTRUMENT_TIMER;
+	else if (es->analyze)
+		instrument_option |= INSTRUMENT_ROWS;
+
 	if (es->buffers)
 		instrument_option |= INSTRUMENT_BUFFERS;
 
@@ -951,29 +969,42 @@ ExplainNode(PlanState *planstate, List *ancestors,
 
 		if (es->format == EXPLAIN_FORMAT_TEXT)
 		{
-			appendStringInfo(es->str,
-							 " (actual time=%.3f..%.3f rows=%.0f loops=%.0f)",
-							 startup_sec, total_sec, rows, nloops);
+			if (planstate->instrument->need_timer)
+				appendStringInfo(es->str,
+								 " (actual time=%.3f..%.3f rows=%.0f loops=%.0f)",
+								 startup_sec, total_sec, rows, nloops);
+			else
+				appendStringInfo(es->str,
+								 " (actual rows=%.0f loops=%.0f)",
+								 rows, nloops);
 		}
 		else
 		{
-			ExplainPropertyFloat("Actual Startup Time", startup_sec, 3, es);
-			ExplainPropertyFloat("Actual Total Time", total_sec, 3, es);
+			if (planstate->instrument->need_timer)
+			{
+				ExplainPropertyFloat("Actual Startup Time", startup_sec, 3, es);
+				ExplainPropertyFloat("Actual Total Time", total_sec, 3, es);
+			}
 			ExplainPropertyFloat("Actual Rows", rows, 0, es);
 			ExplainPropertyFloat("Actual Loops", nloops, 0, es);
 		}
 	}
 	else if (es->analyze)
 	{
+
 		if (es->format == EXPLAIN_FORMAT_TEXT)
 			appendStringInfo(es->str, " (never executed)");
-		else
+		else if (planstate->instrument->need_timer)
 		{
 			ExplainPropertyFloat("Actual Startup Time", 0.0, 3, es);
 			ExplainPropertyFloat("Actual Total Time", 0.0, 3, es);
+		}
+		else
+		{
 			ExplainPropertyFloat("Actual Rows", 0.0, 0, es);
 			ExplainPropertyFloat("Actual Loops", 0.0, 0, es);
 		}
+
 	}
 
 	/* in text format, first line ends here */
diff --git a/src/backend/executor/instrument.c b/src/backend/executor/instrument.c
index dde73b7..2c749b1 100644
--- a/src/backend/executor/instrument.c
+++ b/src/backend/executor/instrument.c
@@ -29,17 +29,19 @@ InstrAlloc(int n, int instrument_options)
 {
 	Instrumentation *instr;
 
-	/* timer is always required for now */
-	Assert(instrument_options & INSTRUMENT_TIMER);
-
 	/* initialize all fields to zeroes, then modify as needed */
 	instr = palloc0(n * sizeof(Instrumentation));
-	if (instrument_options & INSTRUMENT_BUFFERS)
+	if (instrument_options & (INSTRUMENT_BUFFERS | INSTRUMENT_TIMER))
 	{
 		int			i;
+		bool		need_buffers = instrument_options & INSTRUMENT_BUFFERS;
+		bool		need_timer = instrument_options & INSTRUMENT_TIMER;
 
 		for (i = 0; i < n; i++)
-			instr[i].need_bufusage = true;
+		{
+			instr[i].need_bufusage = need_buffers;
+			instr[i].need_timer = need_timer;
+		}
 	}
 
 	return instr;
@@ -49,7 +51,7 @@ InstrAlloc(int n, int instrument_options)
 void
 InstrStartNode(Instrumentation *instr)
 {
-	if (INSTR_TIME_IS_ZERO(instr->starttime))
+	if (instr->need_timer && INSTR_TIME_IS_ZERO(instr->starttime))
 		INSTR_TIME_SET_CURRENT(instr->starttime);
 	else
 		elog(DEBUG2, "InstrStartNode called twice in a row");
@@ -68,16 +70,22 @@ InstrStopNode(Instrumentation *instr, double nTuples)
 	/* count the returned tuples */
 	instr->tuplecount += nTuples;
 
-	if (INSTR_TIME_IS_ZERO(instr->starttime))
+	/* let's update the time only if the timer was requested */
+	if (instr->need_timer)
 	{
-		elog(DEBUG2, "InstrStopNode called without start");
-		return;
-	}
 
-	INSTR_TIME_SET_CURRENT(endtime);
-	INSTR_TIME_ACCUM_DIFF(instr->counter, endtime, instr->starttime);
+		if (INSTR_TIME_IS_ZERO(instr->starttime))
+		{
+			elog(DEBUG2, "InstrStopNode called without start");
+			return;
+		}
 
-	INSTR_TIME_SET_ZERO(instr->starttime);
+		INSTR_TIME_SET_CURRENT(endtime);
+		INSTR_TIME_ACCUM_DIFF(instr->counter, endtime, instr->starttime);
+
+		INSTR_TIME_SET_ZERO(instr->starttime);
+
+	}
 
 	/* Add delta of buffer usage since entry to node's totals */
 	if (instr->need_bufusage)
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index 3443259..a987c43 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -31,6 +31,7 @@ typedef struct ExplainState
 	bool		analyze;		/* print actual times */
 	bool		costs;			/* print costs */
 	bool		buffers;		/* print buffer usage */
+	bool		timing;			/* print timing */
 	ExplainFormat format;		/* output format */
 	/* other states */
 	PlannedStmt *pstmt;			/* top of plan */
diff --git a/src/include/executor/instrument.h b/src/include/executor/instrument.h
index 9ecb544..084302e 100644
--- a/src/include/executor/instrument.h
+++ b/src/include/executor/instrument.h
@@ -31,14 +31,16 @@ typedef struct BufferUsage
 /* Flag bits included in InstrAlloc's instrument_options bitmask */
 typedef enum InstrumentOption
 {
-	INSTRUMENT_TIMER = 1 << 0,	/* needs timer */
+	INSTRUMENT_TIMER = 1 << 0,	/* needs timer (and row counts) */
 	INSTRUMENT_BUFFERS = 1 << 1,	/* needs buffer usage */
+	INSTRUMENT_ROWS = 1 << 2,	/* needs row count */
 	INSTRUMENT_ALL = 0x7FFFFFFF
 } InstrumentOption;
 
 typedef struct Instrumentation
 {
 	/* Parameters set at node creation: */
+	bool		need_timer;	    /* TRUE if we need timer data */
 	bool		need_bufusage;	/* TRUE if we need buffer usage data */
 	/* Info about current plan cycle: */
 	bool		running;		/* TRUE if we've completed first tuple */