> Is there ever a need to have more than one conversion for a given > combination of encodings?
Sure. For example, several Unicode and SJIS mappings exist depending on vendors or standards. M$ has its own, Apple has another one... If a user want to employ Apple's map, he could define his own implicit conversion. > And if I have more than one combination > registered, which one is used by the implicit server/client conversion? That depends on current name space. You could find such an example in the conversion regression test. Note that you cannot define more than one implicit conversion for a schema/server encoding/client encoding combination. > Also, if my server encoding is A and my client encoding is B, and I do > > SELECT convert('some string' using a_to_c); -- not B > > or even > > SELECT convert('some string' using e_to_f); > > this would surely lead to bogus results? Yes. Choosing right conversion is callers responsibilty. > What's the use of all this? One example. A user wants to apply lower() to Unicode database. select convert(lower(convert('X' using utf_8_to_iso_8859_1)) using iso_8859_1_to_utf_8); -- Tatsuo Ishii ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org