Well, I sit corrected.   Obviously I misread that.

> It's not so much that they are necessarily inefficient as that they
> constrain the planner's freedom of action.  You need to think a lot more
> carefully about the order of joining than when you use inner joins.

I've also found that OUTER JOINS constrain the types of joins that can/will be 
used as well as the order.  Maybe you didn't intend it that way, but (for 
example) OUTER JOINs seem much more likely to use expensive merge joins.

Josh Berkus
Aglio Database Solutions
San Francisco

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