Re: Slow query in JDBC

First output show the output when the query is executed from sql command
line. The second output show when it is executed from the application. AS
per the output it is clear that the when the query is executed through JDBC
its not using the index (health_index) instead its doing sequence scan.
Please let us know how this issue can be resolved from JDBC?

1.)

*Limit (cost=510711.53..510711.58 rows=20 width=72)*

* -> Sort (cost=510711.53..511961.53 rows=500000 width=72)*

* Sort Key: health_timeseries_table.health*

* -> WindowAgg (cost=0.98..497406.71 rows=500000 width=72)*

* -> Merge Left Join (cost=0.98..491156.71 rows=500000
width=64)*

* Merge Cond: (object_table.uuid =
health_timeseries_table.mobid)*

* -> Unique (cost=0.42..57977.00 rows=500000
width=64)*

* -> Index Scan Backward using object_table_pkey
on object_table (cost=0.42..56727.00 rows=500000 width=64)*

* Index Cond: (("timestamp" >= 0) AND
("timestamp" <= '1505990086834'::bigint))*

* Filter: (tenantid = 'perspica'::text)*

* -> Materialize (cost=0.56..426235.64 rows=55526
width=16)*

* -> Unique (cost=0.56..425541.56 rows=55526
width=24)*

* -> Index Only Scan using health_index on
health_timeseries_table (cost=0.56..421644.56 rows=1558800 width=24)*

* Index Cond: (("timestamp" >=
'1505989186834'::bigint) AND ("timestamp" <= '1505990086834'::bigint))*

*LOG: duration: 1971.697 ms*

2.)

Limit (cost=457629.21..457629.26 rows=20 width=72)

-> Sort (cost=457629.21..458879.21 rows=500000 width=72)

Sort Key: health_timeseries_table.health

-> WindowAgg (cost=367431.49..444324.39 rows=500000 width=72)

-> Merge Left Join (cost=367431.49..438074.39 rows=500000
width=64)

Merge Cond: (object_table.uuid =
health_timeseries_table.mobid)

-> Unique (cost=0.42..57977.00 rows=500000 width=64)

-> Index Scan Backward using object_table_pkey
on object_table (cost=0.42..56727.00 rows=500000 width=64)

Index Cond: (("timestamp" >= '0'::bigint)
AND ("timestamp" <= '1505990400000'::bigint))

Filter: (tenantid = 'perspica'::text)

-> Materialize (cost=367431.07..373153.32 rows=55526
width=16)

-> Unique (cost=367431.07..372459.24 rows=55526
width=24)

-> Sort (cost=367431.07..369945.16
rows=1005634 width=24)

Sort Key:
health_timeseries_table.mobid DESC, health_timeseries_table."timestamp"
DESC, health_timeseries_table.health

-> Seq Scan on
health_timeseries_table (cost=0.00..267171.00 rows=1005634 width=24)

Filter: (("timestamp" >=
'1505989500000'::bigint) AND ("timestamp" <= '1505990400000'::bigint))

On Thu, Sep 28, 2017 at 2:56 PM, Pavy Philippe <Philippe(dot)Pavy(at)worldline(dot)com>
wrote:

> https://www.postgresql.org/docs/current/static/auto-explain.html
>
>
> -----Message d'origine-----
> De : pgsql-performance-owner(at)postgresql(dot)org [mailto:pgsql-performance-
> owner(at)postgresql(dot)org] De la part de Julien Rouhaud
> Envoyé : jeudi 28 septembre 2017 11:21
> À : Subramaniam C
> Cc : pgsql-performance(at)postgresql(dot)org
> Objet : Re: [PERFORM] Slow query in JDBC
>
> On Thu, Sep 28, 2017 at 10:58 AM, Subramaniam C <
> subramaniam31784(at)gmail(dot)com> wrote:
> > I configured cursor_tuple_fraction to 1 but still I am facing the same
> > issue.
>
> Can you show explain (analyze, buffers) of the query when run from psql
> and run from application (you can use auto_explain for that if needed, see
> https://www.postgresql.org/docs/current/static/auto-explain.html)
>
>
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