On Tue, May 29, 2007 at 10:00:06AM -0400, Tom Lane wrote:
> In practice though, I find it hard to imagine a pair of encodings for
> which the growth rate is more than 3x. You'd need something that
> translates a single-byte character into 4 or more bytes (pretty
> unlikely, especially considering we require all these encodings to be
> ASCII supersets); or something that translates a 2-byte character into
> more than 6 bytes.
Many characters in the 0x80..0xff range of single-byte encodings
like LATIN1 become four bytes in GB18030 (e.g., LATIN1 f1 = GB18030
81 30 8a 39). PostgreSQL doesn't currently support such conversions
but it's something to be aware of.
--
Michael Fuhr