Re: Jdbc/postgres performance - Mailing list pgsql-performance

From Merlin Moncure
Subject Re: Jdbc/postgres performance
Date
Msg-id b42b73150610171328r508ab94dmd70dac6ed78474aa@mail.gmail.com
Whole thread Raw
In response to Jdbc/postgres performance  ("Rohit_Behl" <Rohit_Behl@infosys.com>)
Responses Re: Jdbc/postgres performance
List pgsql-performance
On 10/17/06, Rohit_Behl <Rohit_Behl@infosys.com> wrote:
> Select events.event_id, ctrl.real_name, events.tsds, events.value, events.lds, events.correction, ctrl.type,
ctrl.freqfrom table events, iso_midw_control ctrl where events.obj_id = ctrl.obj_id and events.event_id > ?::bigint
orderby events.event_id limit ? 

unfortunately parameterized limit statements cause problems due to the
fact the planner has a hard coded 'guess' of 10% of rows returned when
the plan is generated.  I mention this everyime query hints proposal
comes up :-).

best you can do is to try turning off seqscan and possibly bitmap scan
when the plan is generated.

merlin

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