I have a number of tables with the general structure:
Column | Type | Modifiers -----------+--------------------------+----------- timestamp | timestamp with time zone | value | double precision | Indexes: tbl__timestamp
and I would like to find the union of the timestamps. Something like:
select timestamp from cal_quat_1 WHERE timestamp BETWEEN '2004-02-01 00:03:30' AND '2004-02-01 00:04:00' UNION select timestamp from cal_quat_2 WHERE timestamp BETWEEN '2004-02-01 00:03:30' AND '2004-02-01 00:04:00' UNION select timestamp from cal_quat_4 WHERE timestamp BETWEEN '2004-02-01 00:03:30' AND '2004-02-01 00:04:00' UNION select timestamp from cal_quat_4 WHERE timestamp BETWEEN '2004-02-01 00:03:30' AND '2004-02-01 00:04:00' UNION select timestamp from cal_ccd_temp WHERE timestamp BETWEEN '2004-02-01 00:03:30' AND '2004-02-01 00:04:00';
Is there a less shorter, less redundant way of writing this?
Cheers, Randall
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SELECT t1.timestamp FROM ( SELECT timestamp FROM cal_quat_1 UNION SELECT timestamp FROM cal_quat_2 UNION SELECT timestamp FROM cal_quat_3 UNION SELECT timestamp FROM cal_quat_4 UNION SELECT timestamp FROM cal_ccd_temp ) t1 WHERE t1.timestamp BETWEEN '2004-02-01 00:03:30' AND '2004-02-01 00:04:00';
is technically shorter but I have no idea how well it will compare performance wise with what you have got. If this runs a lot slower then compare the output from explain analyze of the two queries.
Nick
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