What is best practice when extracting both current and average from a
table? Demonstration table here contains data from a cheap weather station.
I can obviously get the current reading like this:
select temp_out, dewpoint
from weather
where datetime between (now() - '10 minutes'::interval) and now()
order by datetime desc
limit 1;
and I can get averages like this:
select avg(temp_out) as avg_temp_out, avg(dewpoint) as avg_dewpoint
from weather
where datetime between (now() - '45 minutes'::interval) and now();
In both cases there are a dozen or so columns in total. How are these
best merged to yield a single row? Some form of join, or window functions?
--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk
[Opinions above are the author's, not those of his employers or colleagues]
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