Один из методов получения профиля рабочей нагрузки и истории ожиданий в PostgreSQL

Продолжение статьи «Попытка создать аналог ASH для PostgreSQL «.

В статье будет рассмотрено и показано на конкретных запросах и примерах — какую же полезную информацию можно получить с помощью истории представления pg_stat_activity.

Предупреждение.
В связи с новизной темы и незавершением периода тестирования, статья может содержать ошибки. Критика и замечания всячески приветствуются и ожидаются.

Входные данные

История представления pg_stat_statements

pg_stat_history

CREATE TABLE pg_stat_history ( 
id SERIAL, 
snapshot_timestamp  timestamp without time zone, 
database_id integer,
dbid oid,
userid oid,
queryid bigint,
query text,
calls bigint, 
total_time double precision, 
min_time double precision, 
max_time double precision, 
mean_time double precision,
stddev_time double precision,
rows bigint,
shared_blks_hit bigint, 
shared_blks_read bigint, 
shared_blks_dirtied bigint, 
shared_blks_written bigint, 
local_blks_hit bigint, 
local_blks_read bigint,
local_blks_dirtied bigint, 
local_blks_written bigint, 
temp_blks_read bigint,
temp_blks_written bigint,
blk_read_time double precision, 
blk_write_time double precision, 
baseline_id integer );

Таблица заполняется каждый час, используя dblink к целевой базе данных. Самый интересный и полезный столбец в таблице, разумеется queryid.

История представления pg_stat_activity

archive_pg_stat_activity

CREATE TABLE archive_pg_stat_activity
(
  timepoint timestamp without time zone,
  datid             oid, 
  datname           name,
  pid               integer,
  usesysid          oid,
  usename           name,
  application_name  text,
  client_addr       inet,
  client_hostname   text,
  client_port       integer,
  backend_start     timestamp without time zone,
  xact_start        timestamp without time zone,
  query_start       timestamp without time zone,
  state_change      timestamp without time zone,
  wait_event_type   text,                     
  wait_event        text,                   
  state             text,                  
  backend_xid       xid,                 
  backend_xmin      xid,                
  query             text,               
  backend_type      text,
  queryid           bigint
);

Таблица представляет собой секционированную по часам таблицу history_pg_stat_activity (Подробнее здесь — pg_stat_statements + pg_stat_activity + loq_query = pg_ash? и здесь — Попытка создать аналог ASH для PostgreSQL.)

Выходные данные

CLUSTER CPU TIME (SYSTEM + CLIENTS )

Запрос

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NULL  ) AND
			aa.state = 'active'
 )
 SELECT count(*) 
 INTO cpu_total
 FROM t ;

Пример

CLUSTER CPU TIME (SYSTEM + CLIENTS ) : 28:37:46

CLUSTER WAITINGS TIME

Запрос

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NOT NULL  ) AND
			aa.state = 'active'
 )
 SELECT count(*) 
 INTO cpu_total
 FROM t ;

Пример

CLUSTER WAITINGS TIME : 30:12:49

Total pg_stat_statements values

Запрос

 --TOTAL pg_stat
  SELECT 
    SUM(calls) AS calls, SUM(total_time)  AS total_time, SUM(rows) AS rows ,
	SUM(shared_blks_hit)  AS shared_blks_hit,SUM(shared_blks_read) AS shared_blks_read ,
	SUM(shared_blks_dirtied) AS shared_blks_dirtied,SUM(shared_blks_written) AS shared_blks_written , 
    SUM(local_blks_hit) AS local_blks_hit , SUM(local_blks_read) AS local_blks_read , 
	SUM(local_blks_dirtied) AS local_blks_dirtied , SUM(local_blks_written)  AS local_blks_written,
	SUM(temp_blks_read) AS temp_blks_read, SUM(temp_blks_written) temp_blks_written , 
	SUM(blk_read_time) AS blk_read_time , SUM(blk_write_time) AS blk_write_time
  INTO 
    pg_total_stat_history_rec
  FROM 
    pg_stat_history
  WHERE 
 	snapshot_timestamp BETWEEN pg_stat_history_begin AND pg_stat_history_end AND 
	queryid IS NULL;

SQL DBTIME — общее время выполнения запросов

Запрос

dbtime_total = interval '1 millisecond' * pg_total_stat_history_rec.total_time ;

Пример

SQL DBTIME : 136:49:36

SQL CPU TIME-время CPU затраченное на выполнение запросов

Запрос

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NULL  ) AND
			backend_type = 'client backend' AND 
			aa.state = 'active'
 )
 SELECT count(*) 
 INTO cpu_total
 FROM t ;

Пример

SQL CPU TIME : 27:40:15

SQL WAITINGS TIME — общее время ожиданий для запросов

Запрос

WITH 
 t AS
 (
	SELECT 		
			date_trunc('second', timepoint)
	FROM 	activity_hist.archive_pg_stat_activity aa
	WHERE 	timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour')  AND 
			( aa.wait_event_type IS NOT NULL  ) AND
			aa.state = 'active' AND 
		backend_type = 'client backend'
 )
 SELECT count(*) 
 INTO waiting_total
 FROM t ;

Пример

SQL WAITINGS TIME : 30:04:09

Следующие запросы тривиальны и для экономии места детали реализации опускаются:

Пример

| SQL IOTIME : 19:44:50
| SQL READ TIME : 19:44:32
| SQL WRITE TIME : 00:00:17
|
| SQL CALLS : 12188248
-------------------------------------------------------------
| SQL SHARED BLOCKS READS : 7997039120
| SQL SHARED BLOCKS HITS : 8868286092
| SQL SHARED BLOCKS HITS/READS % : 110.89
| SQL SHARED BLOCKS DIRTED : 419945
| SQL SHARED BLOCKS WRITTEN : 19857
|
| SQL TEMPORARY BLOCKS READS : 7836169
| SQL TEMPORARY BLOCKS WRITTEN : 10683938

Переходим, к самому интересному разделу

WAITINGS STATICTICS

TOP 10 WAITINGS BY TOTAL WAIT TIME FOR CLIENTS PROCESSES

Запрос

SELECT 
  wait_event_type , wait_event ,
  get_system_waiting_duration( wait_event_type , wait_event ,pg_stat_history_begin+(current_hour_diff * interval '1 hour') ,pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration 
FROM
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type != 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY 
  wait_event_type, wait_event
ORDER BY 3 DESC
LIMIT 10

Пример

+------------------------------------------------------------------------------------
| TOP 10 WAITINGS BY TOTAL WAIT TIME FOR SYSTEM PROCESSES
+-----+------------------------------+--------------------+--------------------
|    #|               wait_event_type|          wait_event|            duration
+-----+------------------------------+--------------------+--------------------
|    1|                      Activity| LogicalLauncherMain|            10:43:28
|    2|                      Activity|      AutoVacuumMain|            10:42:49
|    3|                      Activity|       WalWriterMain|            10:28:53
|    4|                      Activity|    CheckpointerMain|            10:23:50
|    5|                      Activity|        BgWriterMain|            09:11:59
|    6|                      Activity|   BgWriterHibernate|            01:37:46
|    7|                            IO|        BufFileWrite|            00:02:35
|    8|                        LWLock|      buffer_mapping|            00:01:54
|    9|                            IO|        DataFileRead|            00:01:23
|   10|                            IO|            WALWrite|            00:00:59
+-----+------------------------------+--------------------+--------------------

TOP 10 WAITINGS BY TOTAL WAIT TIME FOR CLIENTS PROCESSES

Запрос

SELECT 
  wait_event_type , wait_event ,
  get_clients_waiting_duration( wait_event_type , wait_event , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration
FROM 
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type = 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY wait_event_type, wait_event
ORDER BY 3 DESC
LIMIT 10

Пример

+-----+------------------------------+--------------------+--------------------+----------
|    #|               wait_event_type|          wait_event|            duration|  % dbtime
+-----+------------------------------+--------------------+--------------------+----------
|    1|                          Lock|       transactionid|            08:16:47|      6.05
|    2|                            IO|        DataFileRead|            06:13:41|      4.55
|    3|                       Timeout|             PgSleep|            02:53:21|      2.11
|    4|                        LWLock|      buffer_mapping|            00:40:42|       0.5
|    5|                        LWLock|           buffer_io|            00:17:17|      0.21
|    6|                            IO|        BufFileWrite|            00:01:34|      0.02
|    7|                          Lock|               tuple|            00:01:32|      0.02
|    8|                        Client|          ClientRead|            00:01:19|      0.02
|    9|                            IO|         BufFileRead|            00:00:37|      0.01
|   10|                        LWLock|      buffer_content|            00:00:08|         0
+-----+------------------------------+--------------------+--------------------+----------

WAITINGS TYPES BY TOTAL WAIT TIME, FOR SYSTEM PROCESSES

Запрос

SELECT 
  wait_event_type ,
  get_system_waiting_type_duration( wait_event_type , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration
FROM
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND  backend_type != 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY wait_event_type
ORDER BY 2 DESC

Пример

+-----+------------------------------+--------------------
|    #|               wait_event_type|            duration
+-----+------------------------------+--------------------
|    1|                      Activity|            53:08:45
|    2|                            IO|            00:06:24
|    3|                        LWLock|            00:03:02
+-----+------------------------------+--------------------

WAITINGS TYPES BY TOTAL WAIT TIME, FOR CLIENTS PROCESSES

Запрос

SELECT 
  wait_event_type ,
  get_clients_waiting_type_duration( wait_event_type , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration
FROM
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type = 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY wait_event_type
ORDER BY 2 DESC

Пример

+-----+------------------------------+--------------------+--------------------
|    #|               wait_event_type|            duration|            % dbtime
+-----+------------------------------+--------------------+--------------------
|    1|                          Lock|            08:18:19|                6.07
|    2|                            IO|            06:16:01|                4.58
|    3|                       Timeout|            02:53:21|                2.11
|    4|                        LWLock|            00:58:12|                0.71
|    5|                        Client|            00:01:19|                0.02
|    6|                           IPC|            00:00:04|                   0
+-----+------------------------------+--------------------+--------------------

Длительности ожиданий, для системных процессов и отдельных запросов.

WAITINGS FOR SYSTEM PROCESSES

Запрос

SELECT 
  backend_type , datname , wait_event_type , wait_event , get_backend_type_waiting_duration( backend_type , wait_event_type , wait_event , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration 
FROM 
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type != 'client backend' AND wait_event_type IS NOT NULL 
GROUP BY backend_type , datname , wait_event_type , wait_event
ORDER BY 5 DESC

Пример

+-----+-----------------------------+----------+--------------------+----------------------+--------------------
|    #|                 backend_type|    dbname|     wait_event_type|            wait_event|            duration
+-----+-----------------------------+----------+--------------------+----------------------+--------------------
|    1| logical replication launcher|          |            Activity|   LogicalLauncherMain|            10:43:28
|    2|          autovacuum launcher|          |            Activity|        AutoVacuumMain|            10:42:49
|    3|                    walwriter|          |            Activity|         WalWriterMain|            10:28:53
|    4|                 checkpointer|          |            Activity|      CheckpointerMain|            10:23:50
|    5|            background writer|          |            Activity|          BgWriterMain|            09:11:59
|    6|            background writer|          |            Activity|     BgWriterHibernate|            01:37:46
|    7|              parallel worker|      tdb1|                  IO|          BufFileWrite|            00:02:35
|    8|              parallel worker|      tdb1|              LWLock|        buffer_mapping|            00:01:41
|    9|              parallel worker|      tdb1|                  IO|          DataFileRead|            00:01:22
|   10|              parallel worker|      tdb1|                  IO|           BufFileRead|            00:00:59
|   11|                    walwriter|          |                  IO|              WALWrite|            00:00:57
|   12|              parallel worker|      tdb1|              LWLock|             buffer_io|            00:00:47
|   13|            autovacuum worker|      tdb1|              LWLock|        buffer_mapping|            00:00:13
|   14|            background writer|          |                  IO|         DataFileWrite|            00:00:12
|   15|                 checkpointer|          |                  IO|         DataFileWrite|            00:00:11
|   16|                    walwriter|          |              LWLock|          WALWriteLock|            00:00:09
|   17|                 checkpointer|          |              LWLock|          WALWriteLock|            00:00:06
|   18|            background writer|          |              LWLock|          WALWriteLock|            00:00:06
|   19|                    walwriter|          |                  IO|          WALInitWrite|            00:00:02
|   20|            autovacuum worker|      tdb1|              LWLock|          WALWriteLock|            00:00:02
|   21|                    walwriter|          |                  IO|           WALInitSync|            00:00:02
|   22|            autovacuum worker|      tdb1|                  IO|          DataFileRead|            00:00:01
|   23|                 checkpointer|          |                  IO| ControlFileSyncUpdate|            00:00:01
|   24|            background writer|          |                  IO|              WALWrite|            00:00:01
|   25|            background writer|          |                  IO|         DataFileFlush|            00:00:01
|   26|                 checkpointer|          |                  IO|         SLRUFlushSync|            00:00:01
|   27|            autovacuum worker|      tdb1|                  IO|              WALWrite|            00:00:01
|   28|                 checkpointer|          |                  IO|          DataFileSync|            00:00:01
+-----+-----------------------------+----------+--------------------+----------------------+--------------------

WAITINGS FOR SQL — ожидания для отдельных запросов по queryid

Запрос

SELECT 
queryid , datname , wait_event_type , wait_event , get_query_waiting_duration( queryid ,  wait_event_type , wait_event , pg_stat_history_begin+(current_hour_diff * interval '1 hour') , pg_stat_history_end+(current_hour_diff * interval '1 hour') ) as duration 
FROM 
  activity_hist.archive_pg_stat_activity aa
WHERE 
  timepoint BETWEEN pg_stat_history_begin+(current_hour_diff * interval '1 hour') AND pg_stat_history_end+(current_hour_diff * interval '1 hour') AND backend_type = 'client backend' AND wait_event_type IS NOT NULL AND queryid IS NOT NULL 
GROUP BY queryid , datname , wait_event_type , wait_event
ORDER BY 1 , 5 DESC 

Пример

+-----+-------------------------+----------+--------------------+--------------------+--------------------+--------------------
|    #|                  queryid|    dbname|     wait_event_type|          wait_event|            waitings|               total
|     |                         |          |                    |                    |            duration|            duration
+-----+-------------------------+----------+--------------------+--------------------+--------------------+--------------------
|    1|     -8247416849404883188|      tdb1|              Client|          ClientRead|            00:00:02|
|    2|     -6572922443698419129|      tdb1|              Client|          ClientRead|            00:00:05|
|    3|     -6572922443698419129|      tdb1|                  IO|        DataFileRead|            00:00:01|
|    4|     -5917408132400665328|      tdb1|              Client|          ClientRead|            00:00:04|
|    5|     -4091009262735781873|      tdb1|              Client|          ClientRead|            00:00:03|
|    6|     -1473395109729441239|      tdb1|              Client|          ClientRead|            00:00:01|
|    7|        28942442626229688|      tdb1|                  IO|        BufFileWrite|            00:01:34|            00:46:06
|    8|        28942442626229688|      tdb1|              LWLock|      buffer_mapping|            00:01:05|            00:46:06
|    9|        28942442626229688|      tdb1|                  IO|        DataFileRead|            00:00:44|            00:46:06
|   10|        28942442626229688|      tdb1|                  IO|         BufFileRead|            00:00:37|            00:46:06
|   11|        28942442626229688|      tdb1|              LWLock|           buffer_io|            00:00:35|            00:46:06
|   12|        28942442626229688|      tdb1|              Client|          ClientRead|            00:00:05|            00:46:06
|   13|        28942442626229688|      tdb1|                 IPC| MessageQueueReceive|            00:00:03|            00:46:06
|   14|        28942442626229688|      tdb1|                 IPC|    BgWorkerShutdown|            00:00:01|            00:46:06
|   15|       389015618226997618|      tdb1|                Lock|       transactionid|            03:55:09|            04:14:15
|   16|       389015618226997618|      tdb1|                  IO|        DataFileRead|            03:23:09|            04:14:15
|   17|       389015618226997618|      tdb1|              LWLock|      buffer_mapping|            00:12:09|            04:14:15
|   18|       389015618226997618|      tdb1|              LWLock|           buffer_io|            00:10:18|            04:14:15
|   19|       389015618226997618|      tdb1|                Lock|               tuple|            00:00:35|            04:14:15
|   20|       389015618226997618|      tdb1|              LWLock|        WALWriteLock|            00:00:02|            04:14:15
|   21|       389015618226997618|      tdb1|                  IO|       DataFileWrite|            00:00:01|            04:14:15
|   22|       389015618226997618|      tdb1|              LWLock|        SyncScanLock|            00:00:01|            04:14:15
|   23|       389015618226997618|      tdb1|              Client|          ClientRead|            00:00:01|            04:14:15
|   24|       734234407411547467|      tdb1|              Client|          ClientRead|            00:00:11|
|   25|       734234407411547467|      tdb1|              LWLock|      buffer_mapping|            00:00:05|
|   26|       734234407411547467|      tdb1|                  IO|        DataFileRead|            00:00:02|
|   27|      1237430309438971376|      tdb1|              LWLock|      buffer_mapping|            00:02:18|            02:45:40
|   28|      1237430309438971376|      tdb1|                  IO|        DataFileRead|            00:00:27|            02:45:40
|   29|      1237430309438971376|      tdb1|              Client|          ClientRead|            00:00:02|            02:45:40
|   30|      2404820632950544954|      tdb1|              Client|          ClientRead|            00:00:01|
|   31|      2515308626622579467|      tdb1|              Client|          ClientRead|            00:00:02|
|   32|      4710212362688288619|      tdb1|              LWLock|      buffer_mapping|            00:03:08|            02:18:21
|   33|      4710212362688288619|      tdb1|                  IO|        DataFileRead|            00:00:22|            02:18:21
|   34|      4710212362688288619|      tdb1|              Client|          ClientRead|            00:00:06|            02:18:21
|   35|      4710212362688288619|      tdb1|              LWLock|           buffer_io|            00:00:02|            02:18:21
|   36|      9150846928388977274|      tdb1|                  IO|        DataFileRead|            00:01:19|
|   37|      9150846928388977274|      tdb1|              LWLock|      buffer_mapping|            00:00:34|
|   38|      9150846928388977274|      tdb1|              Client|          ClientRead|            00:00:10|
|   39|      9150846928388977274|      tdb1|              LWLock|           buffer_io|            00:00:01|
+-----+-------------------------+----------+--------------------+--------------------+--------------------+--------------------

CLIENT SQL STATICTICS — TOP запросов

Запросы для получения опять, таки тривиальны и для экономии места, не приводятся.

Примеры

+------------------------------------------------------------------------------------
| CLIENT SQL ordered by Elapsed Time
+--------------------+----------+----------+----------+----------+----------+--------------------
|        elapsed time|     calls|  % dbtime|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+--------------------
|            04:14:15|        19|       3.1|     10.83|     11.52|      tdb1|  389015618226997618
|            02:45:40|       746|      2.02|      4.23|      0.08|      tdb1| 1237430309438971376
|            02:18:21|       749|      1.69|      3.39|       0.1|      tdb1| 4710212362688288619
|            00:46:06|       375|      0.56|      0.94|      0.41|      tdb1|   28942442626229688
+--------------------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by CPU Time
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            cpu time|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            02:59:49|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            01:10:12|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|            00:56:15|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
|            00:15:35|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by User I/O Wait Time
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|        io_wait time|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            03:23:10|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            00:02:54|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|            00:00:27|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|            00:00:22|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by Shared Buffers Reads
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|       buffers reads|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|          1056388566|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            11709251|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|             3439004|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|             3373330|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by Disk Reads Time
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|           read time|     calls|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|            02:16:30|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
|            00:04:50|       375|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|            00:01:10|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
|            00:00:57|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
| CLIENT SQL ordered by Executions
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|               calls|      rows|  % dbtime|total_time|     % CPU|      % IO|    dbname|             queryid
+--------------------+----------+----------+----------+----------+----------+----------+--------------------
|                 749|       749|      1.69|  02:18:21|      3.39|       0.1|      tdb1| 4710212362688288619
|                 746|       746|      2.02|  02:45:40|      4.23|      0.08|      tdb1| 1237430309438971376
|                 375|         0|      0.56|  00:46:06|      0.94|      0.41|      tdb1|   28942442626229688
|                  19|        19|       3.1|  04:14:15|     10.83|     11.52|      tdb1|  389015618226997618
+--------------------+----------+----------+----------+----------+----------+----------+--------------------

Итог

Используя представленные запросы и получаемую отчетность, можно получать более полную картину для анализа и решения проблем деградации производительности по отдельным запросам и всего кластера, в целом.

Развитие

Пока планы на развитие следующие:

• Дополнить отчетность историей блокировок. Запросы тестируются и будут представлены в ближайшее время.
• Использовать расширение TimescaleDB для хранения истории pg_stat_activity и pg_locks.
• Подготовить пакетное решение на github для массового разворачивания на продакшн базах.

Продолжение следует…

Источник: habr.com