gahayden (9/15/2011)
I have to agree with SSC Eights. Why not use a composite key?For many years, when storage was expensive, single fields were often used to depict mutiple entities and there continue to be numerous examples of this in accounting and manufacturing. Similar stratagy was applied when DOS limited file naming to 8 characters.
Why go back there? What's wrong with 2 fields?
Everything's wrong with two columns: You see, it's not an issue of storage, but the performance impact of using suboptimal datatypes. Using more than one column compounds the problem as both columns, if used as a primary key, have to be present in foreign key columns referencing the primary key. Since there tend to be many more FK records than PK records in your average database structure, the bloat compounds further, impacting performance as it does so.