- B(R) =
number of
blocks used to
store/hold
the tuples of
relation R
- T(R) =
number of
tupless in
relation R
- V(R,a) =
number of
different values found in the
attribute a
Common use:
1
# blocks with (a = constant) = ----- × B(R)
V(R,a)
1
# tuples with (a = constant) = ----- × T(R)
V(R,a)
|
- V(R,
[a1,a2,...,ak]) =
number of
different values found in the
attributes
a1,a2,...,ak
V(R, a) = | πa1,a2,...,ak(R) |
|
|