Package org.modeshape.jcr.query.process

This package defines the QueryProcessor interface, which is responsible for constructing for each query a tree of ProcessingComponent objects that each are responsible for processing a specific aspect of the query and returning the tuples to the parent component.

See: Description

Interface Summary

Interface	Description
JoinComponent.Joinable	Interface defining the value of a tuple that is used in the join condition.
JoinComponent.TupleMerger	A component that will merge the supplied tuple on the left side of a join with the supplied tuple on the right side of the join, to produce a single tuple with all components from the left and right tuples.
JoinComponent.ValueSelector	Interface defining the value of a tuple that is used in the join condition.
ProcessingComponent.DynamicOperation	Interface for evaluating a DynamicOperand to return the resulting value.
Processor	Interface for a query processor.
SelectComponent.CompareOperation	Interface defining the Comparison functionality for a specific Operator.
SelectComponent.ConstraintChecker	Interface used to determine whether a tuple satisfies all of the constraints applied to the SELECT node.

Class Summary

Class	Description
AbstractAccessComponent	A reusable base class for ProcessingComponent implementations that does everything except obtain the correct QueryResults.Location objects for the query results.
DelegatingComponent
DependentQueryComponent	A ProcessingComponent that executes a dependent query node by first executing the left component and then executing the right component.
DistinctComponent	A ProcessingComponent implementation that removes duplicates.
DistinctOfSortedComponent	An efficient ProcessingComponent that removes duplicates from an already-sorted set of results.
ExceptComponent
IntersectComponent
JoinComponent
LimitComponent
MergeJoinComponent	Create a processing component that performs a merge-join algorithm.
NestedLoopJoinComponent
NoResultsComponent
ProcessingComponent	A component that performs (some) portion of the query processing by returning the tuples that result from this stage of processing.
ProjectComponent	A ProcessingComponent implementation that performs a PROJECT operation to reduce the columns that appear in the results.
QueryEngine	A query engine that is able to execute formal queries expressed in the Graph API's Abstract Query Model.
QueryProcessor<ProcessingContextType>	An abstract Processor implementation that builds a tree of ProcessingComponent objects to perform the different parts of the query processing logic.
QueryResultColumns	Defines the columns associated with the results of a query.
QueryResultColumns.ColumnInfo
QueryResultColumns.WrappedReformatter
QueryResults	The resulting output of a query.
SelectComponent
SetOperationComponent
SortLocationsComponent
SortValuesComponent	A ProcessingComponent implementation that performs a PROJECT operation to reduce the columns that appear in the results.
UnionComponent

Package org.modeshape.jcr.query.process Description

This package defines the QueryProcessor interface, which is responsible for constructing for each query a tree of ProcessingComponent objects that each are responsible for processing a specific aspect of the query and returning the tuples to the parent component.

At the bottom are the "access" components that perform the low-level access of the tuples from the graph container. Above these are the other components that implement various operations, such as limits, joins (using merge and nested loop algorithms), unions, intersects, distinct, sorts, and even column projections. At the top is a single component that produces tuples that represent the results of the query.

Once the QueryProcessor creates the ProcessingComponent assembly, the top-level component is executed. Execution involves requesting from the child processing component(s) the next batch of results, processing each of the tuples according to the specific ProcessingComponent algorithm, and finally returning the processed tuples.