Re: Arrays Design Question

Achilleus ,

> performance for the following problem:
> I want to store the factors of a linear formula of unknown degree
> (but less
> than 10) in a table for online stats/graphs on historical data (about
> 200 Mb).
> I am thinking of
> a) Store each formula as a float8[] array and then write a pgsql
> function in C
> to compute the result given the value of variable x.
> b) Add 10 columns of type float8 and store 0 values where the
> position of the
> column exceeds the degree of the formula.

BOTH of the above are poor approaches that will lead to headaches for
you later on. Instead:

c. Store each formula in a column in another table with a parent-child
relationship to your main table, i.e.

online_stats stat_formulas
--------------- ------------------
online_stat_id ------------->online_stat_id
formula_number
formula

This is basic relational database design. You should probably pick up
a copy of "Relational Database Design for Mere Mortals" before you
get yourself into a real mess ...

-Josh Berkus