Add support for pg_stat_statements queryId

Author: ildus

Makefile

@@ -4,11 +4,14 @@ MODULE_big = pg_wait_sampling
 OBJS = pg_wait_sampling.o collector.o
 
 EXTENSION = pg_wait_sampling
-DATA = pg_wait_sampling--1.0.sql
+EXTVERSION = 1.1
+DATA_built = pg_wait_sampling--$(EXTVERSION).sql
+DATA = pg_wait_sampling--1.0--1.1.sql
 
 REGRESS = load queries
 
 EXTRA_REGRESS_OPTS=--temp-config=$(top_srcdir)/$(subdir)/conf.add
+EXTRA_CLEAN = pg_wait_sampling--$(EXTVERSION).sql
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config
@@ -20,3 +23,6 @@ top_builddir = ../..
 include $(top_builddir)/src/Makefile.global
 include $(top_srcdir)/contrib/contrib-global.mk
 endif
+
+$(EXTENSION)--$(EXTVERSION).sql: setup.sql
+	cat $^ > $@

README.md

@@ -27,24 +27,22 @@ When `pg_wait_sampling` is enabled, it collects two kinds of statistics.
    a client who periodically read this history and dump it somewhere, user
    can have continuous history.
  * Waits profile.  It's implemented as in-memory hash table where count
-   of samples are accumulated per each process and each wait event.  This hash
+   of samples are accumulated per each process and each wait event
+   (and each query with `pg_stat_statements`).  This hash
    table can be reset by user request.  Assuming there is a client who
    periodically dumps profile and resets it, user can have statistics of
    intensivity of wait events among time.
 
+In combination with `pg_stat_statements` this extension can also provide
+per query statistics.
+
 `pg_wait_sampling` launches special background worker for gathering the
 statistics above.
 
-Authors
--------
-
- * Alexander Korotkov <[email protected]>, Postgres Professional,
-   Moscow, Russia
-
 Availability
 ------------
 
-`pg_wait_sampling` is realized as an extension and not available in default
+`pg_wait_sampling` is implemented as an extension and not available in default
 PostgreSQL installation. It is available from
 [github](https://github.com/postgrespro/pg_wait_sampling)
 under the same license as
@@ -88,6 +86,7 @@ all processed including background workers.
 | pid         | int4        | Id of process           |
 | event_type  | text        | Name of wait event type |
 | event       | text        | Name of wait event      |
+| queryid     | int8        | Id of query             |
 
 `pg_wait_sampling_get_current(pid int4)` returns the same table for single given
 process.
@@ -101,6 +100,7 @@ in-memory ring buffer.
 | ts          | timestamptz | Sample timestamp        |
 | event_type  | text        | Name of wait event type |
 | event       | text        | Name of wait event      |
+| queryid     | int8        | Id of query             |
 
 `pg_wait_sampling_profile` view – profile of wait events obtained by sampling into
 in-memory hash table.
@@ -110,29 +110,33 @@ in-memory hash table.
 | pid         | int4        | Id of process           |
 | event_type  | text        | Name of wait event type |
 | event       | text        | Name of wait event      |
+| queryid     | int8        | Id of query             |
 | count       | text        | Count of samples        |
 
 `pg_wait_sampling_reset_profile()` function resets the profile.
 
 The work of wait event statistics collector worker is controlled by following
 GUCs.
 
-|         Parameter name          | Data type |                  Description                | Default value |
-| ------------------------------- | --------- | ------------------------------------------- | ------------: |
-| pg_wait_sampling.history_size   | int4      | Size of history in-memory ring buffer       |          5000 |
-| pg_wait_sampling.history_period | int4      | Period for history sampling in milliseconds |            10 |
-| pg_wait_sampling.profile_period | int4      | Period for profile sampling in milliseconds |            10 |
-| pg_wait_sampling.profile_pid    | bool      | Whether profile should be per pid           |          true |
+|         Parameter name              | Data type |                  Description                | Default value |
+| ----------------------------------- | --------- | ------------------------------------------- | ------------: |
+| pg_wait_sampling.history_size       | int4      | Size of history in-memory ring buffer       |          5000 |
+| pg_wait_sampling.history_period     | int4      | Period for history sampling in milliseconds |            10 |
+| pg_wait_sampling.profile_period     | int4      | Period for profile sampling in milliseconds |            10 |
+| pg_wait_sampling.profile_pid        | bool      | Whether profile should be per pid           |          true |
+| pg_wait_sampling.profile_queries    | bool      | Whether profile should be per query			|         false |
 
 If `pg_wait_sampling.profile_pid` is set to false, sampling profile wouldn't be
 collected in per-process manner.  In this case the value of pid could would
 be always zero and corresponding row contain samples among all the processes.
 
+While `pg_wait_sampling.profile_queries` is set to false `queryid` field in
+views will be zero.
+
 These GUCs are allowed to be changed by superuser.  Also, they are placed into
 shared memory.  Thus, they could be changed from any backend and affects worker
 runtime.
 
-
 See
 [PostgreSQL documentation](http://www.postgresql.org/docs/devel/static/monitoring-stats.html#WAIT-EVENT-TABLE)
 for list of possible wait events.
@@ -148,3 +152,11 @@ your bug reports.
 If you're lacking of some functionality in `pg_wait_sampling` and feeling power
 to implement it then you're welcome to make pull requests.
 
+Authors
+-------
+
+ * Alexander Korotkov <[email protected]>, Postgres Professional,
+   Moscow, Russia
+ * Ildus Kurbangaliev <[email protected]>, Postgres Professional,
+   Moscow, Russia
+

collector.c

@@ -49,7 +49,7 @@ register_wait_collector(void)
 	worker.bgw_main = collector_main;
 #endif
 	snprintf(worker.bgw_name, BGW_MAXLEN, "pg_wait_sampling collector");
-	worker.bgw_main_arg = (Datum)0;
+	worker.bgw_main_arg = (Datum) 0;
 	RegisterBackgroundWorker(&worker);
 }
 
@@ -168,6 +168,12 @@ probe_waits(History *observations, HTAB *profile_hash,
 		/* Collect next wait event sample */
 		item.pid = proc->pid;
 		item.wait_event_info = proc->wait_event_info;
+
+		if (collector_hdr->profileQueries)
+			item.queryId = proc_queryids[i];
+		else
+			item.queryId = 0;
+
 		item.ts = ts;
 
 		/* Write to the history if needed */
@@ -243,9 +249,13 @@ make_profile_hash()
 
 	hash_ctl.hash = tag_hash;
 	hash_ctl.hcxt = TopMemoryContext;
-	hash_ctl.keysize = offsetof(ProfileItem, count);
-	hash_ctl.entrysize = sizeof(ProfileItem);
 
+	if (collector_hdr->profileQueries)
+		hash_ctl.keysize = offsetof(ProfileItem, count);
+	else
+		hash_ctl.keysize = offsetof(ProfileItem, queryId);
+
+	hash_ctl.entrysize = sizeof(ProfileItem);
 	return hash_create("Waits profile hash", 1024, &hash_ctl,
 					   HASH_FUNCTION | HASH_ELEM);
 }

expected/load_1.out

@@ -6,6 +6,7 @@ CREATE EXTENSION pg_wait_sampling;
  pid        | integer |           |          | 
  event_type | text    |           |          | 
  event      | text    |           |          | 
+ queryid    | bigint  |           |          | 
 
 \d pg_wait_sampling_history
                  View "public.pg_wait_sampling_history"
@@ -15,6 +16,7 @@ CREATE EXTENSION pg_wait_sampling;
  ts         | timestamp with time zone |           |          | 
  event_type | text                     |           |          | 
  event      | text                     |           |          | 
+ queryid    | bigint                   |           |          | 
 
 \d pg_wait_sampling_profile
         View "public.pg_wait_sampling_profile"
@@ -23,6 +25,7 @@ CREATE EXTENSION pg_wait_sampling;
  pid        | integer |           |          | 
  event_type | text    |           |          | 
  event      | text    |           |          | 
+ queryid    | bigint  |           |          | 
  count      | bigint  |           |          | 
 
 DROP EXTENSION pg_wait_sampling;