Re: BUG #4421: convert_to() should be immutable

Andreas Peer <andipeer@gmx.net> writes:
> Well, the use case is a strange one... I would like to use a varchar()
> column for storing a variable-length vector of integers. The numbers are
> represented by the codepoints. Therefore, I need to sort them as binary
> data, not as characters. I would often need to get all the vectors that
> lie in between to vectors, therefore I need the "binary" index.

Use bytea maybe?

> And the code should be as database independent as possible, therefore I
> cannot use an array or another data type that may not be supported by
> other DBMS.

I can't imagine how you'd think that a functional index on convert_to()
would be the most portable solution ...

            regards, tom lane