Hi,
Currently doing some level of aggregrate tables for some data. These
data will be used for slice/dice activity and we want to be able to
play/manipulate the data such that I can get means and stddev data.
Eg: For each Original Column eg:
population_in_town : (I get derivatives)
- mean # of ppl in each town
- stddev # of ppl in each town (stdev calc already uses 2 extra columns
for # of ppl squared and qty of ppl)
- count of ppl
- count of # of ppl is < 100 (to get a percentage of population)
- count of # of ppl is < 500
Hence, I'm seeing a 1:5 column growth here if I put them as column
based.
eg:
| sum of count | sum_of_count_squared | qty | qty < 100 | qty < 500 |
I'm thinking of lumping them into 1 column via an array instead of into
5 different columns. Not sure how to go about this, hence the email to
the list.
something like {244,455,1234,43,23}
query can be done like
sum_of_count / qty = Ave
(sum_of_count_squared * sum_qty ) / (qty * (qty-1)) = STDEV
(sum_qty<100 / sum_qty) = % < 100
(sum_qty<500 / sum_qty) = % < 500
Then there's the issue of speed/responsiveness on doing it.
Help would be appreciated in this.
--
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
