array column and b-tree index allowing only 8191 bytes

Hi all,

I'm checking out some features in pgsql and found out about an array
datatype. As I'm curious to find out how well it performs, I've created
a table that contains an integer[] column and a script to insert about
500K rows in it. The length for the integer[] column is random (can be
10, can be 5000, can be more than that), as are the values in it.

When trying to insert a row, I get the following error:

    index row requires 9796 bytes, maximum size is 8191

If I understood correctly, this is a limit of the b-tree index. Usually
you'd want to use another type of index but, again if I understood
correctly, those are meant mostly for full-text indexing.

Remember, I'm doing this for recreational purposes (the array type is
there, wanted to check out it's performance so why not? :-) ).

So my questions are: is this at all possible? If so, is is possible to
increate that maximum size?

Regards,
Celso