On 01/13/2014 09:48 PM, Robert Haas wrote:
What I'm saying is that if EXPLAIN reports something that's labelled
"Planning Time", it should *be* the planning time, and not anything
else. When we retrieve a plan from cache, it would be sensible not to
report the planning time at all, and IMHO it would also be sensible to
report the time it actually took to plan whenever we originally did
it. But reporting a value that is not the planning time and calling
it the planning time does not seem like a good idea to me.
Here is a patch which only prints when "Planning time" when a prepared
statment actually planned a query. I do not really like how I check for
if it was replanned, but I tried to avoid making changes in plancache.c.
Does this idea look ok?
--
Andreas Karlsson
diff --git a/doc/src/sgml/perform.sgml b/doc/src/sgml/perform.sgml
new file mode 100644
index 2af1738..482490b
*** a/doc/src/sgml/perform.sgml
--- b/doc/src/sgml/perform.sgml
*************** EXPLAIN SELECT * FROM tenk1;
*** 89,94 ****
--- 89,95 ----
QUERY PLAN
-------------------------------------------------------------
Seq Scan on tenk1 (cost=0.00..458.00 rows=10000 width=244)
+ Planning time: 0.113 ms
</screen>
</para>
*************** EXPLAIN SELECT * FROM tenk1;
*** 162,167 ****
--- 163,174 ----
</para>
<para>
+ The <literal>Planning time</literal> shown is the time it took to generate
+ the query plan from the parsed query and optimize it. It does not include
+ rewriting and parsing.
+ </para>
+
+ <para>
Returning to our example:
<screen>
*************** EXPLAIN SELECT * FROM tenk1;
*** 170,175 ****
--- 177,183 ----
QUERY PLAN
-------------------------------------------------------------
Seq Scan on tenk1 (cost=0.00..458.00 rows=10000 width=244)
+ Planning time: 0.113 ms
</screen>
</para>
*************** EXPLAIN SELECT * FROM tenk1 WHERE unique
*** 198,203 ****
--- 206,212 ----
------------------------------------------------------------
Seq Scan on tenk1 (cost=0.00..483.00 rows=7001 width=244)
Filter: (unique1 < 7000)
+ Planning time: 0.104 ms
</screen>
Notice that the <command>EXPLAIN</> output shows the <literal>WHERE</>
*************** EXPLAIN SELECT * FROM tenk1 WHERE unique
*** 234,239 ****
--- 243,249 ----
Recheck Cond: (unique1 < 100)
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)
Index Cond: (unique1 < 100)
+ Planning time: 0.093 ms
</screen>
Here the planner has decided to use a two-step plan: the child plan
*************** EXPLAIN SELECT * FROM tenk1 WHERE unique
*** 262,267 ****
--- 272,278 ----
Filter: (stringu1 = 'xxx'::name)
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)
Index Cond: (unique1 < 100)
+ Planning time: 0.089 ms
</screen>
The added condition <literal>stringu1 = 'xxx'</literal> reduces the
*************** EXPLAIN SELECT * FROM tenk1 WHERE unique
*** 283,288 ****
--- 294,300 ----
-----------------------------------------------------------------------------
Index Scan using tenk1_unique1 on tenk1 (cost=0.29..8.30 rows=1 width=244)
Index Cond: (unique1 = 42)
+ Planning time: 0.076 ms
</screen>
In this type of plan the table rows are fetched in index order, which
*************** EXPLAIN SELECT * FROM tenk1 WHERE unique
*** 311,316 ****
--- 323,329 ----
Index Cond: (unique1 < 100)
-> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0)
Index Cond: (unique2 > 9000)
+ Planning time: 0.094 ms
</screen>
But this requires visiting both indexes, so it's not necessarily a win
*************** EXPLAIN SELECT * FROM tenk1 WHERE unique
*** 331,336 ****
--- 344,350 ----
-> Index Scan using tenk1_unique2 on tenk1 (cost=0.29..71.27 rows=10 width=244)
Index Cond: (unique2 > 9000)
Filter: (unique1 < 100)
+ Planning time: 0.087 ms
</screen>
</para>
*************** WHERE t1.unique1 < 10 AND t1.unique2
*** 364,369 ****
--- 378,384 ----
Index Cond: (unique1 < 10)
-> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.29..7.91 rows=1 width=244)
Index Cond: (unique2 = t1.unique2)
+ Planning time: 0.117 ms
</screen>
</para>
*************** WHERE t1.unique1 < 10 AND t2.unique2
*** 415,420 ****
--- 430,436 ----
-> Materialize (cost=0.29..8.51 rows=10 width=244)
-> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.29..8.46 rows=10 width=244)
Index Cond: (unique2 < 10)
+ Planning time: 0.119 ms
</screen>
The condition <literal>t1.hundred < t2.hundred</literal> can't be
*************** WHERE t1.unique1 < 100 AND t1.unique2
*** 462,467 ****
--- 478,484 ----
Recheck Cond: (unique1 < 100)
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0)
Index Cond: (unique1 < 100)
+ Planning time: 0.182 ms
</screen>
</para>
*************** WHERE t1.unique1 < 100 AND t1.unique2
*** 492,497 ****
--- 509,515 ----
-> Sort (cost=197.83..200.33 rows=1000 width=244)
Sort Key: t2.unique2
-> Seq Scan on onek t2 (cost=0.00..148.00 rows=1000 width=244)
+ Planning time: 0.195 ms
</screen>
</para>
*************** WHERE t1.unique1 < 100 AND t1.unique2
*** 528,533 ****
--- 546,552 ----
-> Index Scan using tenk1_unique2 on tenk1 t1 (cost=0.29..656.28 rows=101 width=244)
Filter: (unique1 < 100)
-> Index Scan using onek_unique2 on onek t2 (cost=0.28..224.79 rows=1000 width=244)
+ Planning time: 0.176 ms
</screen>
which shows that the planner thinks that sorting <literal>onek</> by
*************** WHERE t1.unique1 < 10 AND t1.unique2
*** 564,569 ****
--- 583,589 ----
Index Cond: (unique1 < 10)
-> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.29..7.91 rows=1 width=244) (actual time=0.021..0.022 rows=1 loops=10)
Index Cond: (unique2 = t1.unique2)
+ Planning time: 0.181 ms
Total runtime: 0.501 ms
</screen>
*************** WHERE t1.unique1 < 100 AND t1.unique2
*** 612,617 ****
--- 632,638 ----
Recheck Cond: (unique1 < 100)
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.049..0.049 rows=100 loops=1)
Index Cond: (unique1 < 100)
+ Planning time: 0.194 ms
Total runtime: 8.008 ms
</screen>
*************** EXPLAIN ANALYZE SELECT * FROM tenk1 WHER
*** 635,640 ****
--- 656,662 ----
Seq Scan on tenk1 (cost=0.00..483.00 rows=7000 width=244) (actual time=0.016..5.107 rows=7000 loops=1)
Filter: (ten < 7)
Rows Removed by Filter: 3000
+ Planning time: 0.083 ms
Total runtime: 5.905 ms
</screen>
*************** EXPLAIN ANALYZE SELECT * FROM polygon_tb
*** 657,662 ****
--- 679,685 ----
Seq Scan on polygon_tbl (cost=0.00..1.05 rows=1 width=32) (actual time=0.044..0.044 rows=0 loops=1)
Filter: (f1 @> '((0.5,2))'::polygon)
Rows Removed by Filter: 4
+ Planning time: 0.040 ms
Total runtime: 0.083 ms
</screen>
*************** EXPLAIN ANALYZE SELECT * FROM polygon_tb
*** 675,680 ****
--- 698,704 ----
Index Scan using gpolygonind on polygon_tbl (cost=0.13..8.15 rows=1 width=32) (actual time=0.062..0.062 rows=0 loops=1)
Index Cond: (f1 @> '((0.5,2))'::polygon)
Rows Removed by Index Recheck: 1
+ Planning time: 0.034 ms
Total runtime: 0.144 ms
</screen>
*************** EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM
*** 705,710 ****
--- 729,735 ----
-> Bitmap Index Scan on tenk1_unique2 (cost=0.00..19.78 rows=999 width=0) (actual time=0.227..0.227 rows=999 loops=1)
Index Cond: (unique2 > 9000)
Buffers: shared hit=5
+ Planning time: 0.088 ms
Total runtime: 0.423 ms
</screen>
*************** EXPLAIN ANALYZE UPDATE tenk1 SET hundred
*** 732,737 ****
--- 757,763 ----
Recheck Cond: (unique1 < 100)
-> Bitmap Index Scan on tenk1_unique1 (cost=0.00..5.04 rows=101 width=0) (actual time=0.043..0.043 rows=100 loops=1)
Index Cond: (unique1 < 100)
+ Planning time: 0.079 ms
Total runtime: 14.727 ms
ROLLBACK;
*************** EXPLAIN ANALYZE SELECT * FROM tenk1 WHER
*** 817,822 ****
--- 843,849 ----
Index Cond: (unique2 > 9000)
Filter: (unique1 < 100)
Rows Removed by Filter: 287
+ Planning time: 0.096 ms
Total runtime: 0.336 ms
</screen>
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
new file mode 100644
index 35264dc..4e3f571
*** a/doc/src/sgml/ref/explain.sgml
--- b/doc/src/sgml/ref/explain.sgml
*************** ROLLBACK;
*** 145,151 ****
<para>
Include information on the estimated startup and total cost of each
plan node, as well as the estimated number of rows and the estimated
! width of each row. This parameter defaults to <literal>TRUE</literal>.
</para>
</listitem>
</varlistentry>
--- 145,152 ----
<para>
Include information on the estimated startup and total cost of each
plan node, as well as the estimated number of rows and the estimated
! width of each row. Additionally it controls if the planning time is
! displayed. This parameter defaults to <literal>TRUE</literal>.
</para>
</listitem>
</varlistentry>
*************** EXPLAIN SELECT * FROM foo;
*** 289,295 ****
QUERY PLAN
---------------------------------------------------------
Seq Scan on foo (cost=0.00..155.00 rows=10000 width=4)
! (1 row)
</programlisting>
</para>
--- 290,297 ----
QUERY PLAN
---------------------------------------------------------
Seq Scan on foo (cost=0.00..155.00 rows=10000 width=4)
! Planning time: 0.114 ms
! (2 rows)
</programlisting>
</para>
*************** EXPLAIN (FORMAT JSON) SELECT * FROM foo;
*** 309,315 ****
"Total Cost": 155.00, +
"Plan Rows": 10000, +
"Plan Width": 4 +
! } +
} +
]
(1 row)
--- 311,318 ----
"Total Cost": 155.00, +
"Plan Rows": 10000, +
"Plan Width": 4 +
! }. +
! "Planning Time": 0.114 +
} +
]
(1 row)
*************** EXPLAIN SELECT * FROM foo WHERE i = 4;
*** 328,334 ****
--------------------------------------------------------------
Index Scan using fi on foo (cost=0.00..5.98 rows=1 width=4)
Index Cond: (i = 4)
! (2 rows)
</programlisting>
</para>
--- 331,338 ----
--------------------------------------------------------------
Index Scan using fi on foo (cost=0.00..5.98 rows=1 width=4)
Index Cond: (i = 4)
! Planning time: 0.073 ms
! (3 rows)
</programlisting>
</para>
*************** EXPLAIN (FORMAT YAML) SELECT * FROM foo
*** 348,354 ****
Total Cost: 5.98 +
Plan Rows: 1 +
Plan Width: 4 +
! Index Cond: "(i = 4)"
(1 row)
</programlisting>
--- 352,359 ----
Total Cost: 5.98 +
Plan Rows: 1 +
Plan Width: 4 +
! Index Cond: "(i = 4)" +
! Planning Time: 0.073
(1 row)
</programlisting>
*************** EXPLAIN SELECT sum(i) FROM foo WHERE i &
*** 380,385 ****
--- 385,391 ----
Aggregate (cost=23.93..23.93 rows=1 width=4)
-> Index Scan using fi on foo (cost=0.00..23.92 rows=6 width=4)
Index Cond: (i < 10)
+ Planning time: 0.088 ms
(3 rows)
</programlisting>
</para>
*************** EXPLAIN ANALYZE EXECUTE query(100, 200);
*** 401,406 ****
--- 407,413 ----
Group Key: foo
-> Index Scan using test_pkey on test (cost=0.29..9.29 rows=50 width=8) (actual time=0.039..0.091 rows=99 loops=1)
Index Cond: ((id > $1) AND (id < $2))
+ Planning time: 0.197 ms
Total runtime: 0.225 ms
(5 rows)
</programlisting>
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
new file mode 100644
index 0dba928..02809ae
*** a/src/backend/commands/explain.c
--- b/src/backend/commands/explain.c
*************** ExplainOneQuery(Query *query, IntoClause
*** 320,332 ****
(*ExplainOneQuery_hook) (query, into, es, queryString, params);
else
{
! PlannedStmt *plan;
/* plan the query */
plan = pg_plan_query(query, 0, params);
/* run it (if needed) and produce output */
! ExplainOnePlan(plan, into, es, queryString, params);
}
}
--- 320,338 ----
(*ExplainOneQuery_hook) (query, into, es, queryString, params);
else
{
! PlannedStmt *plan;
! instr_time planstart, planduration;
!
! INSTR_TIME_SET_CURRENT(planstart);
/* plan the query */
plan = pg_plan_query(query, 0, params);
+ INSTR_TIME_SET_CURRENT(planduration);
+ INSTR_TIME_SUBTRACT(planduration, planstart);
+
/* run it (if needed) and produce output */
! ExplainOnePlan(plan, into, es, queryString, params, planduration, false);
}
}
*************** ExplainOneUtility(Node *utilityStmt, Int
*** 403,409 ****
*/
void
ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
! const char *queryString, ParamListInfo params)
{
DestReceiver *dest;
QueryDesc *queryDesc;
--- 409,416 ----
*/
void
ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
! const char *queryString, ParamListInfo params,
! instr_time planduration, bool cached)
{
DestReceiver *dest;
QueryDesc *queryDesc;
*************** ExplainOnePlan(PlannedStmt *plannedstmt,
*** 484,489 ****
--- 491,507 ----
/* Create textual dump of plan tree */
ExplainPrintPlan(es, queryDesc);
+ if (es->costs && !cached)
+ {
+ double plantime = INSTR_TIME_GET_DOUBLE(planduration);
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ appendStringInfo(es->str, "Planning time: %.3f ms\n",
+ 1000.0 * plantime);
+ else
+ ExplainPropertyFloat("Planning Time", 1000.0 * plantime, 3, es);
+ }
+
/* Print info about runtime of triggers */
if (es->analyze)
ExplainPrintTriggers(es, queryDesc);
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
new file mode 100644
index 49c4093..4ddffb8
*** a/src/backend/commands/prepare.c
--- b/src/backend/commands/prepare.c
*************** ExplainExecuteQuery(ExecuteStmt *execstm
*** 624,634 ****
{
PreparedStatement *entry;
const char *query_string;
! CachedPlan *cplan;
List *plan_list;
ListCell *p;
ParamListInfo paramLI = NULL;
EState *estate = NULL;
/* Look it up in the hash table */
entry = FetchPreparedStatement(execstmt->name, true);
--- 624,635 ----
{
PreparedStatement *entry;
const char *query_string;
! CachedPlan *cplan, *lastplan;
List *plan_list;
ListCell *p;
ParamListInfo paramLI = NULL;
EState *estate = NULL;
+ instr_time planstart, planduration;
/* Look it up in the hash table */
entry = FetchPreparedStatement(execstmt->name, true);
*************** ExplainExecuteQuery(ExecuteStmt *execstm
*** 654,662 ****
--- 655,675 ----
queryString, estate);
}
+ lastplan = entry->plansource->gplan;
+ if (lastplan)
+ lastplan->refcount++;
+
+ INSTR_TIME_SET_CURRENT(planstart);
+
/* Replan if needed, and acquire a transient refcount */
cplan = GetCachedPlan(entry->plansource, paramLI, true);
+ INSTR_TIME_SET_CURRENT(planduration);
+ INSTR_TIME_SUBTRACT(planduration, planstart);
+
+ if (lastplan)
+ ReleaseCachedPlan(lastplan, false);
+
plan_list = cplan->stmt_list;
/* Explain each query */
*************** ExplainExecuteQuery(ExecuteStmt *execstm
*** 665,671 ****
PlannedStmt *pstmt = (PlannedStmt *) lfirst(p);
if (IsA(pstmt, PlannedStmt))
! ExplainOnePlan(pstmt, into, es, query_string, paramLI);
else
ExplainOneUtility((Node *) pstmt, into, es, query_string, paramLI);
--- 678,684 ----
PlannedStmt *pstmt = (PlannedStmt *) lfirst(p);
if (IsA(pstmt, PlannedStmt))
! ExplainOnePlan(pstmt, into, es, query_string, paramLI, planduration, cplan == lastplan);
else
ExplainOneUtility((Node *) pstmt, into, es, query_string, paramLI);
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
new file mode 100644
index e097710..fb67cda
*** a/src/include/commands/explain.h
--- b/src/include/commands/explain.h
*************** extern void ExplainOneUtility(Node *util
*** 67,74 ****
const char *queryString, ParamListInfo params);
extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into,
! ExplainState *es,
! const char *queryString, ParamListInfo params);
extern void ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc);
extern void ExplainPrintTriggers(ExplainState *es, QueryDesc *queryDesc);
--- 67,74 ----
const char *queryString, ParamListInfo params);
extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into,
! ExplainState *es, const char *queryString,
! ParamListInfo params, instr_time planduration, bool cached);
extern void ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc);
extern void ExplainPrintTriggers(ExplainState *es, QueryDesc *queryDesc);
--
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