Gregory Stark <stark@enterprisedb.com> writes:
> Out of curiosity, what is a "user-defined collation"? Are there SQL statements
> to go around declaring what order code points should be sorted in? That seems
> like it would be... quite tedious!
Hm, that's a good point. SQL99 has
<collation definition> ::= CREATE COLLATION <collation name> FOR <character set
specification> FROM <existing collation name> [ <pad characteristic> ]
<existing collation name> ::= <collation name>
<pad characteristic> ::= NO PAD | PAD SPACE
which seems pretty stupid if you ask me --- all the mechanism required
to manage a new object type, just to enable PAD SPACE or not?
(Especially when PAD SPACE itself is an utterly broken, useless concept
... but I digress.) You might as well just provide all the standard
collations in both variants and be done with it.
The statement looks the same in last year's 200n draft, so it's not
like they were just about to add some more capability.
We might be best off to treat collations like index access methods,
ie, they're theoretically add-able but there's no infrastructure for
managing them, and what's expected is that all the ones you need are
created by initdb.
regards, tom lane