And what happens when we implement NULLS FIRST/LAST correctly?  This is
really a poor choice of representation.

If it's just appending of indexscan's it's not a problem...


One thing I find questionable about this is the assumption that indexes
can support "foo IS NULL" and "foo IS NOT NULL" searches equally
conveniently.  This is demonstrably false for, say, hash.  (Hash could
store null keys by assigning them a fixed hashcode, say 0.  Then it
would be able to handle IS NULL searches, but not IS NOT NULL, because
it can't do full-index scans.)

Is there a guarantee that hash value of some not-null keys doesn't equal to special hash code?


the patch to do IS NULL only.  But if we are going areto support both,
we probably have to have two pg_am flags not one.

GiST isn't effective with single NOT NULL condition ... So, using two flags may be useful.

--
Teodor Sigaev                                   E-mail: [EMAIL PROTECTED]
                                                   WWW: http://www.sigaev.ru/

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