TurtleDB
A mini distributed database system
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Classes | |
class | VariableTableCacheIterator |
class | VariableTableStreamIterator |
Public Member Functions | |
VariableTable (String name) | |
VariableTable (String name, String site) | |
void | setSite (String site) |
String | getSite () |
Schema | getSchema () |
void | accept (QueryVisitor v) throws EmptyQueryVisitor.VisitorException |
String | toString () |
void | setName (String name) |
String | getName () |
int | tupleCount () |
final boolean | isFragment () |
boolean | equals (Object o) |
boolean | equals (VariableTable t) |
boolean | isLeaf () |
RelationStreamIterator | streamIterator () |
RelationIterator | cacheIterator () |
Protected Member Functions | |
VariableTable () | |
Protected Attributes | |
String | m_name |
String | m_site |
A VariableTable is a placeholder for an actual relation. It is used to denote fragments of a query tree that are to be received from or sent to another site.
Definition at line 27 of file VariableTable.java.
ca.uqac.dim.turtledb.VariableTable.VariableTable | ( | ) | [protected] |
Definition at line 39 of file VariableTable.java.
ca.uqac.dim.turtledb.VariableTable.VariableTable | ( | String | name | ) |
Definition at line 46 of file VariableTable.java.
ca.uqac.dim.turtledb.VariableTable.VariableTable | ( | String | name, |
String | site | ||
) |
Definition at line 52 of file VariableTable.java.
void ca.uqac.dim.turtledb.VariableTable.accept | ( | QueryVisitor | v | ) | throws EmptyQueryVisitor.VisitorException [virtual] |
Implements ca.uqac.dim.turtledb.Relation.
Definition at line 91 of file VariableTable.java.
Returns an iterator over tuples of the relation
Implements ca.uqac.dim.turtledb.Relation.
Definition at line 227 of file VariableTable.java.
boolean ca.uqac.dim.turtledb.VariableTable.equals | ( | Object | o | ) |
Definition at line 139 of file VariableTable.java.
boolean ca.uqac.dim.turtledb.VariableTable.equals | ( | VariableTable | t | ) |
Definition at line 148 of file VariableTable.java.
String ca.uqac.dim.turtledb.VariableTable.getName | ( | ) |
Schema ca.uqac.dim.turtledb.VariableTable.getSchema | ( | ) | [virtual] |
Returns the relation's schema
Implements ca.uqac.dim.turtledb.Relation.
Definition at line 82 of file VariableTable.java.
String ca.uqac.dim.turtledb.VariableTable.getSite | ( | ) |
Gets the fragment's site. If the VariableTable is a leaf in a query tree, it is placeholder for data that will be received from this site. If the VariableTable is the root of the query tree, it indicates that the results of the computation are to be sent to this site.
Definition at line 76 of file VariableTable.java.
final boolean ca.uqac.dim.turtledb.VariableTable.isFragment | ( | ) |
Determines if the query tree is a fragment. This is the case when the tree's root is a VariableTable.
Reimplemented from ca.uqac.dim.turtledb.Relation.
Definition at line 133 of file VariableTable.java.
boolean ca.uqac.dim.turtledb.VariableTable.isLeaf | ( | ) |
Determines if a given operator is at the leaf of the query tree. Only instances of Table and VariableTable may be leaves.
Reimplemented from ca.uqac.dim.turtledb.Relation.
Definition at line 156 of file VariableTable.java.
void ca.uqac.dim.turtledb.VariableTable.setName | ( | String | name | ) |
Set the table's name.
name | The table's name |
Definition at line 110 of file VariableTable.java.
void ca.uqac.dim.turtledb.VariableTable.setSite | ( | String | site | ) |
Sets the fragment's site.
site |
Definition at line 64 of file VariableTable.java.
Returns an iterator over tuples of the relation
Implements ca.uqac.dim.turtledb.Relation.
Definition at line 221 of file VariableTable.java.
String ca.uqac.dim.turtledb.VariableTable.toString | ( | ) |
Pretty-prints a relation to a string
Reimplemented from ca.uqac.dim.turtledb.Relation.
Definition at line 99 of file VariableTable.java.
int ca.uqac.dim.turtledb.VariableTable.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.
Reimplemented from ca.uqac.dim.turtledb.UnaryRelation.
Definition at line 125 of file VariableTable.java.
String ca.uqac.dim.turtledb.VariableTable.m_name [protected] |
The fragment's name
Definition at line 32 of file VariableTable.java.
String ca.uqac.dim.turtledb.VariableTable.m_site [protected] |
The fragment's site
Definition at line 37 of file VariableTable.java.