Arrays Design Question - Mailing list pgsql-sql

From Achilleus Mantzios
Subject Arrays Design Question
Date
Msg-id 02032610121202.09965@pc216
Whole thread Raw
Responses Re: Arrays Design Question  ("Josh Berkus" <josh@agliodbs.com>)
List pgsql-sql
Hi,
i am wondering about what could be the best design practice regarding 
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.

The array implementation seems more simple and more neat since it has no 
assumptions about the maximal degree, but it is not standard SQL,
the JDBC might have problems with array types, and i dont know the performance
implications.

Could some one please give a point to read about arrays implementation in 
postgresql, their performance, accessing arrays from server pgsql C 
functions??

Thanx

-- 
Achilleus Mantzios
S/W Engineer
IT dept
Dynacom Tankers Mngmt
tel:    +30-10-8981112
fax:    +30-10-8981877
email:  it@dynacomtm.com       rnd@gatewaynet.com



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