MargaretGillon@xxxxxxxxxxxxxx wrote: > >Jim Nasby <decibel@xxxxxxxxxxx> wrote on 02/08/2007 12:12:00 PM: > > If you do end up back at using foreign keys, I suggest using either a > > smallint or "char"... the savings across the number of fields you're > > looking at would start to add up, especially if you start putting a > > decent number of rows in the table. > > I ended up using Varchar(1). According to the help there is no speed > difference in the character types, on am I misunderstanding something? The "char" type (including quotes) is a very different animal from all those character types the manual you quote is talking about. "char" is a single byte, while varchar(1) and all the rest are a single character, meaning there can be multiple bytes in presence of a multibyte encoding; so Postgres is forced to use a variable-length structure to store it. "char" has no such requirement. It's used in the system catalogs as a "poor man's enum", for example in pg_class.relkind. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
