TurtleDB
A mini distributed database system
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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< Relation > | m_relations |
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).
Definition at line 34 of file NAryRelation.java.
ca.uqac.dim.turtledb.NAryRelation.NAryRelation | ( | ) | [protected] |
Definition at line 41 of file NAryRelation.java.
void ca.uqac.dim.turtledb.NAryRelation.acceptNAry | ( | QueryVisitor | v | ) | throws VisitorException [protected] |
Definition at line 79 of file NAryRelation.java.
Definition at line 56 of file NAryRelation.java.
Returns the arity of the operator, i.e. the number of operands.
Definition at line 66 of file NAryRelation.java.
Schema ca.uqac.dim.turtledb.NAryRelation.getSchema | ( | ) | [virtual] |
Returns the relation's schema
Implements ca.uqac.dim.turtledb.Relation.
Reimplemented in ca.uqac.dim.turtledb.Product.
Definition at line 48 of file NAryRelation.java.
int ca.uqac.dim.turtledb.NAryRelation.tupleCount | ( | ) | [virtual] |
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.
Implements ca.uqac.dim.turtledb.Relation.
Definition at line 71 of file NAryRelation.java.
List<Relation> ca.uqac.dim.turtledb.NAryRelation.m_relations [protected] |
The list of relations the operator acts on
Definition at line 39 of file NAryRelation.java.