>> That's what you tell it with "LEFT" or "RIGHT" (or "FULL"). You *can't* specify outer/inner without telling it that, too -- ex- or implicitly -- so they are *not* orthogonal (=independent). <<

Okay, perhaps "orthogonal" is too strong a word in that they affect the final application of the other. However, the left/right is mostly about which direction to *apply* the other. IOW, They are still very different things.


>> Draw two overlapping circles (or better yet, make them elongated, ellipses) to represent your tables. Orient them horizontally, mark them A and B if .... <<

Time to get out the construction paper........tomarrow.

>>.... "LEFT INNER" query. But your only legal alternatives are "LEFT OUTER", "RIGHT OUTER", "FULL OUTER", and "INNER" -- so they aren't independent. <<

I always thot "LEFT INNER" simply ignored the LEFT (or RIGHT). However, I never tried it. Nor a FULL OUTER. Anybody here ever need that?

I betcha did on your honeymoon.

It is sort of like comparative operations (x > y). The order (left/right) *does* matter *in general*. However, equality (==) is a special case where it does *not* matter. "Inner" is in the same camp as equality comparisons as far as I am concerned. Thus, I conceptually consider INNER a "spacial case".