Hello,
I have a query to aggregate data wich is too slow :-)
Here a simplified example:
create table test
(
time int8, --store the time as epoch
a_group varchar,
category varchar
)
For each group, I need the first/last times and categories , the number
of distinct categories
On Mon, 26 Jan 2009, Marc Mamin m.ma...@intershop.de writes:
create table test
(
time int8, --store the time as epoch
a_group varchar,
category varchar
)
...
SELECT
FIRST.a_group,
FIRST.time as first_time,
FIRST.category as first_category,
LAST.time as
