Select statement in formula is REALLy slowing my table down. Any solution?

I have a table with a formula field, that requires a fairly heavy "select" statement.  Problem is that the "select" statement is common to all records in the table (there is not variable within the select that changes based on the other contents of the record).

This means, I'm guessing, that the "select" function gets repeated for every record in the table, which is massively slowing things down.

Is there a way to define a field, function or variable as being global to the table, so that it is only calculated once rather than repeatedly?