Package edu.caltech.nanodb.storage

Interface SequentialTupleFile

All Superinterfaces:

TupleFile

public interface SequentialTupleFile
extends TupleFile

This interface extends the TupleFile interface, adding operations that can be provided on files of tuples that are stored in a specific sequential order. The TupleFile.getFirstTuple() and TupleFile.getNextTuple(edu.caltech.nanodb.relations.Tuple) methods have an additional constraint that they traverse the file's tuples in a specific order, as specified by the getOrderSpec() method.

Method Summary

Modifier and Type	Method	Description
Tuple	findFirstTupleEquals(Tuple searchKey)	Returns the first tuple in the file that has the same search-key value, or null if there are no tuples with this search-key value in the tuple file.
Tuple	findFirstTupleGreaterThan(Tuple searchKey)	Returns the first tuple in the file that has a search-key value that is greater than the specified search-key value, or null if there are no tuples greater than this search-key value in the index.
java.util.List<OrderByExpression>	getOrderSpec()	Returns the column(s) that are used to order the tuples in this sequential file.

Methods inherited from interface edu.caltech.nanodb.storage.TupleFile

addTuple, analyze, deleteTuple, getDBFile, getFirstTuple, getManager, getNextTuple, getSchema, getStats, getTuple, optimize, updateTuple, verify

Method Detail

getOrderSpec

java.util.List<OrderByExpression> getOrderSpec()

Returns the column(s) that are used to order the tuples in this sequential file.

Returns:

the column(s) that are used to order the tuples in this sequential file.

findFirstTupleEquals

Tuple findFirstTupleEquals(Tuple searchKey)

Returns the first tuple in the file that has the same search-key value, or null if there are no tuples with this search-key value in the tuple file. This operation is slightly unusual in that the search key may contain fewer columns than the sequential file does. When this is the case, the sequential file returns the first tuple that matches in the parts of the search key that are actually specified.

Parameters:

searchKey - the tuple to search for

Returns:

The first tuple in the file with the same hash-key values, or null if the file contains no files with the specified search key value. This tuple will actually be backed by the tuple file, so typically it will be a subclass of PageTuple.

findFirstTupleGreaterThan

Tuple findFirstTupleGreaterThan(Tuple searchKey)

Returns the first tuple in the file that has a search-key value that is greater than the specified search-key value, or null if there are no tuples greater than this search-key value in the index. This operation is slightly unusual in that the search key may contain fewer columns than the sequential file does. When this is the case, the sequential file returns the first tuple that is greater in the parts of the search key that are actually specified.

Parameters:

searchKey -

Returns: