On Mon, 18 Nov 2002, Peter Eisentraut wrote: > A collation table essentially consists of a mapping 'character code -> > weight' for every character in the set and some additional considerations > for one-to-many and many-to-one mappings, plus a few feature flags. > > How would a user go about creating such a table? > > CREATE COLLATION foo ( > ... > <10000 lines of data> > ... > ); > > or would it be preferrable to store the table in some external file and > then have the call simply be, say, > > CREATE COLLATION foo SOURCE 'some file';
I'd say the latter makes more sense, but would it be better to use CREATE COLLATION foo FROM EXTERNAL 'some file'; where we say valid implementation defined collation names are references to files of the appropriate type? > Secondly, because each collation table depends on a particular character > encoding (since it is indexed by character code), some sort of magic needs > to happen when someone creates a database with a different encoding than > the template database. One option is to do some mangling on the > registered external file name (such as appending the encoding name to the > file name). Another option is to have the notional pg_collate system > catalog contain a column for the encoding, and then simply ignore all > entries pertaining to encodings other than the database encoding. The SQL92 CREATE COLLATION seems to create a collation for a particular character set, so the latter seems more appropriate to me, especially if we plan to support the full range of SQL's character set/collation/padding attributes at some point. ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
