I am currently designing a database and wanted to know something that may sound trivial, but I thought its still good to confirm before dumping millions of rows in it.
The design requires a few master tables with very limited rows, for e.g. currency_denomination table could at the max have a few records like million / billion / crore (used in india) / lacs (india specific) and so on.
Now what I wanted to ask was whether its any different to have the primary-keys in such master tables as text/varchar rather than integer ? i.e. Can I use a character varying(10) and use the text 'million' / 'billion' instead of a serial / integer type ?
p.s.: I am not as much concerned with the size that it'd take on the data tables, as much as the fact that the select / insert performances shouldn't suffer. However, if that increase in size (per data record) may make a considerable impact on the performance, I would certainly want to take that into account during design phase.