TODO Items

Bruce Momjian <pgman@candle.pha.pa.us> writes:

> TODO item?

On that note several prior conversations I had here ended with WIBNI
conclusions that really ought to be TODO items, in my humble opinion. Two come
to mind off the top of my head resulting in:

. "SELECT * FROM x JOIN y USING (b) WHERE a=?" could use an index on y(a,b) since for a constant value of "a" the index
traversalwould be effectively equivalent just be "b". This could result in an efficient merge join avoiding an
unnecessarysort.
 

. The semantics for row-value expressions is wrong. (a,b) < (x,y) should be true if a<x or if a=x and b<y. Currently it
expandsto a<x and b<y. 
 

. Fix row-value expression handling to not depend on the operator names and instead use btree access method strategy
valuesinstead, allowing row-value expressions on other operators with <,=,> behaviour (ie btree indexable behaviour).
 

. Allow multi-column indexes to be used to optimize row-value expressions. Ie, allow a btree index on a,b to be used to
executean expression like (a,b) < (x,y).
 

-- 
greg