Suresh_ wrote: > I want to add an antijoin operator to PostgreSql. Basically I want to store > the result (tupletableslot) of one join and then compare it with > another..How do I store these results and how do I compare them ?
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I would suggest implementing it at a higher level, rewriting a query like "A ANTIJOIN B" to "A EXCEPT (A JOIN B)". That allows the planner to use whatever methods it has to perform the EXCEPT and the JOIN operations. At the moment there's only one method: sort the inputs and do a merge, but it's conceivable that you could implement EXCEPT using hashing, for example. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
