Re: First query on each connection is too slow

Maksim Milyutin <milyutinma@xxxxxxxxx> · Wed, 13 Jun 2018 13:34:32 +0300



    On 13.06.2018 12:55, Vadim Nevorotin wrote:

    
      Nested Loop Left Join  (cost=0.82..26.41 rows=1 width=4) (actual
        time=49.290..49.297 rows=1 loops=1)

      
           Join Filter: ((s_2.connamespace = n.oid) AND
          (s_2.conrelid = c.oid) AND (a.attnum = ANY (s_2.conkey)))

             Buffers: shared hit=18

          ...

           Planning time: 2.589 ms

             Execution time: 49.467 ms

          
          (45 rows)
          

          And there are two questions: why this problem
            occurs and how can I fix it?
        
      
    You could catch a performance profile of this issue using perf tools
    and iterative executing this query in new sessions via pgbench, for
    example. This would greatly facilitate the search for the cause
        of your problem.

    
    -- 
Regards,
Maksim Milyutin