query problem

Hi,

I sent this to general earlier but I was redirected to performance.

The query have been running ok for quite some time, but after I did a
vacuum on the database, it's very very slow. This IN-query is only 2
ids. Before the problem that in was a subselect-query returning around
6-7 ids. The tables included in the query are described in database.txt.

status=# select count(id) from data;
  count
---------
 1577621
(1 row)

status=# select count(data_id) from data_values;
  count
---------
 9680931
(1 row)

I did run a new explain analyze on the query and found the attached
result. The obvious problem I see is a full index scan in
"idx_dv_data_id". I tried dropping and adding the index again, thats why
is't called "idx_data_values_data_id" in the dump.

status=# EXPLAIN ANALYZE
status-# SELECT
status-#         data.entered,
status-#         data.machine_id,
status-#         datatemplate_intervals.template_id,
status-#         data_values.value
status-# FROM
status-#         data, data_values, datatemplate_intervals
status-# WHERE
status-#         datatemplate_intervals.id = data_values.template_id AND
status-#         data_values.data_id = data.id AND
status-#         data.machine_id IN (2,3) AND
status-#         current_timestamp::timestamp - interval '60 seconds' <
data.entered;



Regards,
Robin


--
Robin Ericsson <robin.ericsson@profecta.se>
Profecta HB