Query Rewriting: Predicate Pushdown
Reserves
Sailors
sid=sid
bid=100
rating > 5
sname
Reserves
Sailors
sid=sid
bid=100
sname
rating > 5
(Scan;
write to
temp T1)
(Scan;
write to
temp T2)
The
earlier we process selections, less tuples we need to manipulate
higher
up in the tree.
Disadvantages?