On Sat, 7 Feb 2004, [ISO-8859-1] Hans-J?rgen Sch?nig wrote: > 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.
Dilip, you may try our contrib/hstore from http://www.sai.msu.su/~megera/postgres/gist/ which is sort of perl hash and could provide you some flexibility. But you may indeed need to think if you really needed such structure :) Oleg > > 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 > > > > > > > Regards, Oleg _____________________________________________________________ Oleg Bartunov, sci.researcher, hostmaster of AstroNet, Sternberg Astronomical Institute, Moscow University (Russia) Internet: [EMAIL PROTECTED], http://www.sai.msu.su/~megera/ phone: +007(095)939-16-83, +007(095)939-23-83 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
