I am writing an ODBC driver and a small SQL-Engine for a datasource of
my firm.
ODBC tools use a lot of DNF queries like

SELECT ...
WHERE
PK1=? AND PK2=?
OR
PK1=? AND PK2=?
OR
PK1=? AND PK2=?
OR
....

MS Access builds also DNF-queries. Where can I find a description of
possible SQL query-optimezer, that can handle such queries without
converting them to CNF. How it's done in PostgreSQL 7.x? I've found,
that PQ 6.x have used CNF with some special optimizations for keyset
queries. Where can I find it?

Thanks