Re: Add CASEFOLD() function.

One question I have is whether we want this function to normalize the
output.

Yes, we do.

I am sorry that I am so late to the party, but I am currently writing the Change Proposal for the SQL Standard for this function.

For <fold> (which includes LOWER() and UPPER()), the text says in Section 6.35 GR 7.e:

If the character set of <character factor> is UTF8, UTF16, or UTF32, then FR is replaced by
    Case:
        i) If the <search condition> S IS NORMALIZED evaluates to True, then NORMALIZE (FR)
        ii) Otherwise, FR.

Here, FR is the result of the function and S is its argument.

It does not appear to me that our LOWER and UPPER functions obey this rule, so there is a valid argument that we should continue to ignore it. Or, we can say that we have at least one of three compliant.

--

Vik Fearing