On Wed, Dec 10, 2003 at 04:54:54PM -0500, Tom Lane wrote:
> Currently, this is accomplished by the roundabout method of converting
> the WHERE clause to CNF (AND-of-ORs) and then simplifying duplicate
> sub-clauses within an OR:
> (a AND b) OR (a AND c)
> expands by repeated application of the distributive law to
> (a OR a) AND (a OR c) AND (b OR a) AND (b OR c)
This is wrong.
What would be true however is:
(a OR b) AND (b OR C)
= (a AND b) OR (a AND c) OR (b AND b) OR (b AND C)
(Replace AND by * and OR by +)
Kurt