Hi,
I found a slow part of the query:
SELECT
* date(extract(YEAR FROM m.taken)||'-1-1') d1,*
* date(extract(YEAR FROM m.taken)||'-1-31') d2*
FROM
climate.city c,
climate.station s,
climate.station_category sc,
climate.measurement m
WHERE
c.id = 5148 AND ...
Date extraction is 3.2 seconds, but without is 1.5 seconds. The PL/pgSQL
code that actually runs (where p_month1, p_day1, and p_month2, p_day2 are
integers):
* date(extract(YEAR FROM m.taken)||''-'||p_month1||'-'||p_day1||''')
d1,
date(extract(YEAR FROM m.taken)||''-'||p_month2||'-'||p_day2||''')
d2
*
What is a better way to create those dates (without string concatenation, I
presume)?
Dave
