com.amazon.carbonado.qe
Interface QueryExecutor<S extends Storable>

All Known Implementing Classes:

AbstractQueryExecutor, DelegatedQueryExecutor, FilteredQueryExecutor, FullScanQueryExecutor, IndexedQueryExecutor, IterableQueryExecutor, JoinedQueryExecutor, KeyQueryExecutor, SortedQueryExecutor, UnionQueryExecutor

public interface QueryExecutor<S extends Storable>

Performs all the actual work of executing a query. QueryExecutors are linked together forming a query plan.

Author:

Brian S O'Neill

See Also:

QueryExecutorFactory

Method Summary

long	count(FilterValues<S> values) Counts the query results using the given filter values.
Cursor<S>	fetch(FilterValues<S> values) Returns a new cursor using the given filter values.
Cursor<S>	fetchSlice(FilterValues<S> values, long from, Long to) Returns a new cursor using the given filter values and slice.
Filter<S>	getFilter() Returns the filter used by this QueryExecutor.
OrderingList<S>	getOrdering() Returns the result ordering of this QueryExecutor.
Class<S>	getStorableType() Returns the storable type that this executor operates on.
boolean	printNative(Appendable app, int indentLevel, FilterValues<S> values) Prints the native query to any appendable, if applicable.
boolean	printPlan(Appendable app, int indentLevel, FilterValues<S> values) Prints the query plan to any appendable, if applicable.

Method Detail

getStorableType

Class<S> getStorableType()

Returns the storable type that this executor operates on.

fetch

Cursor<S> fetch(FilterValues<S> values)
                                 throws FetchException

Returns a new cursor using the given filter values.

Throws:

FetchException

fetchSlice

Cursor<S> fetchSlice(FilterValues<S> values,
                     long from,
                     Long to)
                                      throws FetchException

Returns a new cursor using the given filter values and slice.

Throws:

FetchException

Since:

1.2

count

long count(FilterValues<S> values)
           throws FetchException

Counts the query results using the given filter values.

Throws:

FetchException

getFilter

Filter<S> getFilter()

Returns the filter used by this QueryExecutor.

Returns:

query filter, never null

getOrdering

OrderingList<S> getOrdering()

Returns the result ordering of this QueryExecutor.

Returns:

query ordering in an unmodifiable list

printNative

boolean printNative(Appendable app,
                    int indentLevel,
                    FilterValues<S> values)
                    throws IOException

Prints the native query to any appendable, if applicable.

Parameters:

values - optional

Returns:

false if not implemented

Throws:

IOException

printPlan

boolean printPlan(Appendable app,
                  int indentLevel,
                  FilterValues<S> values)
                  throws IOException

Prints the query plan to any appendable, if applicable.

Parameters:

values - optional

Returns:

false if not implemented

Throws:

IOException