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(dot)ericsson(at)profecta(dot)se>
Profecta HB