Waiting for 9.4 – Provide moving-aggregate support for a bunch of aggregates.

On 13th of April, Tom Lane committed patch:

Provide moving-aggregate support for a bunch of numerical aggregates.
 
First installment of the promised moving-aggregate support in built-in
aggregates: count(), sum(), avg(), stddev() and variance() for
assorted datatypes, though not for float4/float8.
 
In passing, remove a 2001-vintage kluge in interval_accum(): interval
array elements have been properly aligned since around 2003, but
nobody remembered to take out this workaround.  Also, fix a thinko
in the opr_sanity tests for moving-aggregate catalog entries.
 
David Rowley and Florian Pflug, reviewed by Dean Rasheed

On the same day he also committed:

Provide moving-aggregate support for boolean aggregates.
 
David Rowley and Florian Pflug, reviewed by Dean Rasheed

Continue reading Waiting for 9.4 – Provide moving-aggregate support for a bunch of aggregates.

How to deal with timestamps?

Every now and then someone asks, on irc or mailing lists, some question which shows deep misunerstanding (or lack of understanding) of timestamps – especially the ones with time zones.

Since I got bitten by this before, let me describe what timestamps are, how to work with them, and what are the most common pitfalls that you can encounter.

Continue reading How to deal with timestamps?