Postgresql Select view too slow with where clause

Question

The problem is different between view and table execution time.

Why there are so many differences between the two queries ?

The Query 2 query is getting faster with the "LIMIT" Clause but it is very slow now.(Like a Select * From ... limit 1000)

Note: the functions I use in the VIEW does not do any hard work. Language plpgsql.

Query 1 : Execution time = 106.726 ms ;

   EXPLAIN ANALYZE SELECT * FROM dbo.ST_Foto    where     StationId='Sample Guid'  
        and  Tarih <='2018-09-12'   -- Table

Query 1 Explain Analyze ;

  "Seq Scan on st_foto  (cost=0.00..4559.68 rows=103878 width=215) (actual time=0.036..81.046 rows=103938 loops=1)"
"  Filter: ((tarih <= '2018-09-12 00:00:00'::timestamp without time zone) AND (stationid = 'ac5a2189-f931-47c0-9845-d0ff8eac7cb7'::uuid))"
"  Rows Removed by Filter: 20174"
"Planning time: 0.359 ms"
"Execution time: 106.726 ms"

Query 2 Execution Time =30562.223 ms ;

  EXPLAIN ANALYZE SELECT * FROM dbo.VWST_Foto    where     StationId='Sample Guid'  
            and  Tarih <='2018-09-12'   -- VIEW

Query 2 Explain Analyze ;

"Seq Scan on st_foto  (cost=0.00..161415.46 rows=103878 width=439) (actual time=1.364..30510.830 rows=103938 loops=1)"
"  Filter: ((tarih <= '2018-09-12 00:00:00'::timestamp without time zone) AND (stationid = 'ac5a2189-f931-47c0-9845-d0ff8eac7cb7'::uuid))"
"  Rows Removed by Filter: 20174"
"Planning time: 0.517 ms"
"Execution time: 30562.223 ms"

View :

  CREATE    VIEW dbo.vwst_foto AS
     SELECT id,
    created,
    changed,
    createdby,
    changedby,
    intid,
    hardwareid,
    stationid,
    zoom,
    tarih,
    tarihgmt2,
    gunesradyasyon,
    bitkiboyu,
    contrast,
    yesilorani,
    preset,
    rgb,
    fft,
    foto,
    dbo.fn_hardwarefullname(hardwareid) AS hardware_title,
    dbo.fn_stationfullname(stationid) AS station_title,
    dbo.fn_userfullname(createdby) AS createdby_title,
    dbo.fn_userfullname(changedby) AS changedby_title,
    ''::text AS fotograflink,
  /* the basic func */  dbo.fn_enumkeytodescription('ST_Foto'::character varying, 'Zoom'::character varying, zoom::character varying) AS zoom_title,
  /* the basic func */    dbo.fn_enumkeytodescription('ST_Foto'::character varying, 'Preset'::character varying, preset::character varying) AS preset_title
   FROM dbo.st_foto;

My Server has 32 gb ram.

In Addition

explain (analyze, buffers)

analysis :

For View : (Query 2)

"Seq Scan on st_foto  (cost=0.00..161415.46 rows=103878 width=439) (actual time=0.552..30695.394 rows=103938 loops=1)"
"  Filter: ((tarih <= '2018-09-12 00:00:00'::timestamp without time zone) AND (stationid = 'ac5a2189-f931-47c0-9845-d0ff8eac7cb7'::uuid))"
"  Rows Removed by Filter: 20174"
"  Buffers: shared hit=1297179"
"Planning time: 0.489 ms"
"Execution time: 30749.816 ms"

For Table : (Query 1)

"Seq Scan on st_foto  (cost=0.00..4559.68 rows=103878 width=215) (actual time=0.035..80.967 rows=103938 loops=1)"
"  Filter: ((tarih <= '2018-09-12 00:00:00'::timestamp without time zone) AND (stationid = 'ac5a2189-f931-47c0-9845-d0ff8eac7cb7'::uuid))"
"  Rows Removed by Filter: 20174"
"  Buffers: shared hit=2698"
"Planning time: 0.352 ms"
"Execution time: 107.618 ms"

Postgresql Select view too slow with where clause

0 Answers