Re: Design Question (Time Series Data)

Pavel Stehule schrieb:
> 2007/10/4, Jorge Godoy <jgodoy(at)gmail(dot)com>:
>> On Thursday 04 October 2007 06:20:19 Pavel Stehule wrote:
>>
>> I'd use the same solution that he was going to: normalized table including a
>> timestamp (with TZ because of daylight saving times...), a column with a FK
>> to a series table and the value itself. Index the two first columns (if
>> you're searching using the value as a parameter, then index it as well) and
>> this would be the basis of my design for this specific condition.
>>
>> Having good statistics and tuning autovacuum will also help a lot on handling
>> new inserts and deletes.
>>
>
> It's depend on work. Somewhere normalised solution can be better,
> somewhere not. But I belive, if you have lot of timeseries, than
> arrays is better. But I repeat, it's depend on task.
>
> Pavel
>
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Thanks for your input so far. Maybe i should add a few things about what
i will do with the data. There are only a few operations that will be
done in the database:

a) retrieving a slice or the whole series
b) changing the frequency of the series
c) grouping several series (with same time frame/frequency) together in
a result set
d) calculating moving averages and other econometrics stuff :-)

I will always now which series i want (i.e. there will be no case where
i'm searching for a value within the series).

Two questions regarding the arrays: Do you know if these are really
dynamic (e.g. if i have two rows, one with an array with 12 values and
the other one with 1,000 values - will postgres pad the shorter row?)
and is there an built-in function to retrieve arrays as rows (i know
that you can build your own function for that, but i wonder whether
there is a faster native function)

Thank you very much!

Andreas