Re: Aggregation question
От | Hans-Jürgen Schönig |
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Тема | Re: Aggregation question |
Дата | |
Msg-id | 4025200D.4000901@cybertec.at обсуждение исходный текст |
Ответ на | Aggregation question ("Dilip Angal" <dilip_angal@yahoo.com>) |
Ответы |
Re: Aggregation question
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Список | 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 > > -- Cybertec Geschwinde u Schoenig Schoengrabern 134, A-2020 Hollabrunn, Austria Tel: +43/2952/30706 or +43/664/233 90 75 www.cybertec.at, www.postgresql.at, kernel.cybertec.at
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