postgres_exporter stat_statements query

query.sql

explain (analyze, buffers)
SELECT
		pg_get_userbyid(userid) as user,
		pg_database.datname,
		pg_stat_statements.queryid,
		pg_stat_statements.calls as calls_total,
		pg_stat_statements.total_exec_time / 1000.0 as seconds_total,
		pg_stat_statements.rows as rows_total,
		pg_stat_statements.blk_read_time / 1000.0 as block_read_seconds_total,
		pg_stat_statements.blk_write_time / 1000.0 as block_write_seconds_total
		FROM pg_stat_statements
	JOIN pg_database
		ON pg_database.oid = pg_stat_statements.dbid
	WHERE
		total_exec_time > (
		SELECT percentile_cont(0.1)
			WITHIN GROUP (ORDER BY total_exec_time)
			FROM pg_stat_statements
		)
	ORDER BY seconds_total DESC
	LIMIT 100;
  
QUERY PLAN                                                                                                                                                 |
-----------------------------------------------------------------------------------------------------------------------------------------------------------+
Limit  (cost=27.41..27.44 rows=12 width=176) (actual time=33.296..33.304 rows=100 loops=1)                                                                 |
  Buffers: shared hit=1, temp read=1878 written=1878                                                                                                       |
  I/O Timings: temp read=1.656 write=4.335                                                                                                                 |
  InitPlan 1 (returns $0)                                                                                                                                  |
    ->  Aggregate  (cost=12.50..12.51 rows=1 width=8) (actual time=13.352..13.352 rows=1 loops=1)                                                          |
          Buffers: temp read=939 written=939                                                                                                               |
          I/O Timings: temp read=0.714 write=2.136                                                                                                         |
          ->  Function Scan on pg_stat_statements pg_stat_statements_1  (cost=0.00..10.00 rows=1000 width=8) (actual time=9.578..10.939 rows=19403 loops=1)|
                Buffers: temp read=939 written=939                                                                                                         |
                I/O Timings: temp read=0.714 write=2.136                                                                                                   |
  ->  Sort  (cost=14.89..14.92 rows=12 width=176) (actual time=33.295..33.299 rows=100 loops=1)                                                            |
        Sort Key: ((pg_stat_statements.total_exec_time / '1000'::double precision)) DESC                                                                   |
        Sort Method: top-N heapsort  Memory: 70kB                                                                                                          |
        Buffers: shared hit=1, temp read=1878 written=1878                                                                                                 |
        I/O Timings: temp read=1.656 write=4.335                                                                                                           |
        ->  Hash Join  (cost=1.16..14.68 rows=12 width=176) (actual time=27.245..32.039 rows=17462 loops=1)                                                |
              Hash Cond: (pg_stat_statements.dbid = pg_database.oid)                                                                                       |
              Buffers: shared hit=1, temp read=1878 written=1878                                                                                           |
              I/O Timings: temp read=1.656 write=4.335                                                                                                     |
              ->  Function Scan on pg_stat_statements  (cost=0.00..12.50 rows=333 width=56) (actual time=27.231..29.565 rows=17462 loops=1)                |
                    Filter: (total_exec_time > $0)                                                                                                         |
                    Rows Removed by Filter: 1941                                                                                                           |
                    Buffers: temp read=1878 written=1878                                                                                                   |
                    I/O Timings: temp read=1.656 write=4.335                                                                                               |
              ->  Hash  (cost=1.07..1.07 rows=7 width=68) (actual time=0.008..0.009 rows=7 loops=1)                                                        |
                    Buckets: 1024  Batches: 1  Memory Usage: 9kB                                                                                           |
                    Buffers: shared hit=1                                                                                                                  |
                    ->  Seq Scan on pg_database  (cost=0.00..1.07 rows=7 width=68) (actual time=0.006..0.007 rows=7 loops=1)                               |
                          Buffers: shared hit=1                                                                                                            |
Planning Time: 0.306 ms                                                                                                                                    |
Execution Time: 34.553 ms                                                                                                                                  |