Thread: About column type to "varchar(1)" or "char(1)"
Good afternoon, A question about varchar(1) and char(1). If we have two tables test1 (col1 varchar(1), ... ... ); test2 (col1 char(1), ... ... ); In the manuall, it written: *Tip: * There are no performance differences between these three types, apart from the increased storage size when using the blank-padded type. While character(/n/) has performance advantages in some other database systems, it has no such advantages in PostgreSQL. In most situations text or character varying should be used instead. As a result, setup 'col1' to either "varchar(1)" or "char(1)" does not matter at all? Thanks a lot, Emi
On Wed, Aug 24, 2005 at 03:06:18PM -0400, Emi Lu wrote: > Good afternoon, > > A question about varchar(1) and char(1). <snip> > As a result, setup 'col1' to either "varchar(1)" or "char(1)" does not > matter at all? As far as storage goes, nope. Think about it, depending on your encoding, 1 character might be 4 bytes. char() adds padding but varchar() doesn't. That's the difference really... Hope this helps, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.