-
the operation denoted by
which is used to assign expressions to a temporary relation
variable.
Cartesian
product
-
the operation denoted by a cross (X) allows for combination
of information from any two relations.
division
-
the operation denoted by
and used in queries wanting to find results including the phrase
"for all".
natural
join
-
the operation that pertains to a query that involves a Cartestian
product includes a selection operation on the result of the
Cartesian product.
project
-
the operation denoted by the Greek letter pi (),
which is used to return an argument with certain attributes
left out.
rename
-
the operation denoted by the Greek letter rho (),
which allows the results of a relational-algebra expression
to be assigned a name, which can later be used to refer to them.
select
-
the operation denoted by the Greek letter sigma (), which enables
a selection of tuples that satisfy a given predicate.
set
difference
-
the operation denoted by - allows for finding tuples that are
in one relation but are not in another.
set-intersection
-
the operation denoted by
which results in the tuples that are in both relations the operation
is applying to.
union
-
an operation on relations that yields the relation of all tuples
shared by two or more relations. Denoted by the symbol:
which is used to assign expressions to a temporary relation
variable. 
and used in queries wanting to find results including the phrase
"for all".
),
which is used to return an argument with certain attributes
left out.
),
which allows the results of a relational-algebra expression
to be assigned a name, which can later be used to refer to them.
which results in the tuples that are in both relations the operation
is applying to.