TurtleDB
A mini distributed database system
ca.uqac.dim.turtledb.NAryRelation Class Reference
Inheritance diagram for ca.uqac.dim.turtledb.NAryRelation:
Collaboration diagram for ca.uqac.dim.turtledb.NAryRelation:

List of all members.

Classes

class  NAryRelationCacheIterator
class  NAryRelationStreamIterator

Public Member Functions

Schema getSchema ()
void addOperand (Relation r)
int getArity ()
int tupleCount ()

Protected Member Functions

 NAryRelation ()
void acceptNAry (QueryVisitor v) throws VisitorException

Protected Attributes

List< Relationm_relations

Detailed Description

An n-ary relation is an operator that accepts a variable number of operands n, with n 2, i.e. R1R2Rn. Examples of n-ary relations are Union and Intersection. Note that an n-ary relation must be associative (hence the Join is not an n-ary relation).

Author:
sylvain

Definition at line 34 of file NAryRelation.java.


Constructor & Destructor Documentation

Definition at line 41 of file NAryRelation.java.


Member Function Documentation

Definition at line 79 of file NAryRelation.java.

Returns the arity of the operator, i.e. the number of operands.

Returns:
The arity

Definition at line 66 of file NAryRelation.java.

Returns the relation's schema

Returns:
The schema

Implements ca.uqac.dim.turtledb.Relation.

Reimplemented in ca.uqac.dim.turtledb.Product.

Definition at line 48 of file NAryRelation.java.

Returns the number of actual tuples present in the query. This number is different from the cardinality of the query; it counts the number of tuples that are present in the leaves of the query tree.

Returns:
The tuple count

Implements ca.uqac.dim.turtledb.Relation.

Definition at line 71 of file NAryRelation.java.


Member Data Documentation

The list of relations the operator acts on

Definition at line 39 of file NAryRelation.java.


The documentation for this class was generated from the following file: