On Fri, Nov 12, 2010 at 10:17:50AM +0300, Dmitriy Igrishin wrote: > Hey Mark, > > Yeah, I can't imagine an entity in a real project even with more than 100 > columns. Its rare case. > But if you entities (rows/tuples) of some class (table) can contains > variable > set of columns (properties) you can look at hstore contrib module.
What can also work extremely well is storing the data in an array. If you need to access the array based on more meaningful keys you could store key/index pairs in another table.
This approach only works well if you have multiple arrays with the same layout. You probably also need to build up your query dynamically if you need to access variable numbers of datapoints.
Cheers, Peter -- http://sjamaan.ath.cx -- "The process of preparing programs for a digital computer is especially attractive, not only because it can be economically and scientifically rewarding, but also because it can be an aesthetic experience much like composing poetry or music." -- Donald Knuth