Re: Aggregation question - Mailing list pgsql-hackers

From Hans-Jürgen Schönig
Subject Re: Aggregation question
Date
Msg-id 4025200D.4000901@cybertec.at
Whole thread Raw
In response to Aggregation question  ("Dilip Angal" <dilip_angal@yahoo.com>)
Responses Re: Aggregation question  (Oleg Bartunov <oleg@sai.msu.su>)
List pgsql-hackers
if you want to put 1000 columns into one table, your data structure 
needs some further investigation. you are trying to solve the wrong problem.
Regards,
    Hans


Dilip Angal wrote:
> Hi
>  
> I have a situation that I need flexible number columns to model the 
> business requirements. It could go up to 1000 columns and will be a 
> sparse matrix. One option I was considering was to have a table with 
> col1......col1000
> Other option I can consider is store all of them as name values  in 
> single column as  a string
>  
> option 1
> col1  | col2  |col 3 |........|col56|.....|col77|
> 10    | 2     |      |        | 4   |     |     |
> 2     |       |  4   |        |     |.... |6    |
>  
> option 2
>  
> "col1=10,col2=2,col56=4"
> "col1=2,col3=4,col77=6"
>  
> I will have about 50Million such records in a table.
>  
> I need to aggregate the column values for a given day by taking sum of 
> all the rows
>  
> "col1=12,col2=2,col3=4,col56=4,col77=6"
>  
> Second option looks very elegant but aggregation is hard
> Besides, second option may have performance penalty (Especially when you 
> have 50 Million records)
>  
> Any one can give any pointers or comments on how to model this an how to 
> aggregate it?
>  
> Thanks
> Dilip
>  
>  


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