Jdbc/postgres performance - Mailing list pgsql-performance

 Hi

We are facing performance problems in postgres while executing a query. When I execute this query on the server it
takes5-10 seconds. Also I get good performance while executing this query from my code in java with the hard codes
values.I face severe performance problems when I run it using a prepared statement.
 

The query is as follows:

Select events.event_id, ctrl.real_name, events.tsds, events.value, events.lds, events.correction, ctrl.type, ctrl.freq
fromiso_midw_data_update_events events, iso_midw_control ctrl where events.obj_id = ctrl.obj_id and events.event_id >
68971124order by events.event_id limit 2000 

The above query executes in 5-10 seconds.

However the below query executes in 8 mins:

Select events.event_id, ctrl.real_name, events.tsds, events.value, events.lds, events.correction, ctrl.type, ctrl.freq
fromtable events, iso_midw_control ctrl where events.obj_id = ctrl.obj_id and events.event_id > ?::bigint order by
events.event_idlimit ? 

setLong(1, 68971124);

setInt(2, 2000);

The table has close to 5 million rows. The table has the following index:

iso_midw_data_update_events_event_id_key

iso_midw_data_update_events_lds_idx

iso_midw_data_update_events_obj_id_idx


The table is described as follows:

Columns_name data_type type_name        column_size

lds             2       numeric         13

obj_id          2       numeric         6

tsds            2       numeric         13

value           12      varchar         22

correction      2       numeric         1

delta_lds_tsds  2       numeric         13

event_id        -5      bigserial       8

Please tell me what I am missing while setting the prepared statement. I am using postgres7.4.2. and
postgresql-8.1-407.jdbc3.jar.


Thanks


Regards

Rohit


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