com.mckoi.database

Class BlindSearch

java.lang.Object

com.mckoi.database.SelectableScheme

com.mckoi.database.BlindSearch

public final class BlindSearch
extends SelectableScheme

This is a scheme that performs a blind search of a given set. It records no information about how a set element relates to the rest. It blindly searches through the set to find elements that match the given criteria.

This scheme performs badly on large sets because it requires that the database is queried often for information. However since it records no information about the set, memory requirements are non-existant.

This scheme should not be used for anything other than small domain sets because the performance suffers very badly with larger sets. It is ideal for small domain sets because of its no memory overhead. For any select operation this algorithm must check every element in the set.

Author:

Tobias Downer

Field Summary

Fields inherited from class com.mckoi.database.SelectableScheme

EMPTY_LIST, ONE_LIST

Constructor Summary

Constructors

Constructor and Description
BlindSearch(TableDataSource table, int column) The Constructor.

Method Summary

Modifier and Type	Method and Description
SelectableScheme	copy(TableDataSource table, boolean immutable) Returns an exact copy of this scheme including any optimization information.
void	dispose() Disposes and invalidates the BlindSearch.
void	insert(int row) This scheme doesn't take any notice of insertions or removals.
void	readFrom(InputStream in) Reads the entire state of the scheme from the input stream.
void	remove(int row) This scheme doesn't take any notice of insertions or removals.
IntegerVector	selectAll() These are the select operations that are the main purpose of the scheme.
IntegerVector	selectRange(SelectableRange range) Selects the given range of values from this index.
IntegerVector	selectRange(SelectableRange[] ranges) Selects a set of ranges from this index.
void	writeTo(OutputStream out) Writes the entire state of the scheme to the output stream.

Methods inherited from class com.mckoi.database.SelectableScheme

Debug, getCellContents, getColumn, getSubsetScheme, getSystem, getTable, internalOrderIndexSet, isImmutable, selectAllNonNull, selectBetween, selectEqual, selectFirst, selectGreater, selectGreaterOrEqual, selectLast, selectLess, selectLessOrEqual, selectNotEqual, selectNotFirst, selectNotLast, setImmutable, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

BlindSearch

public BlindSearch(TableDataSource table,
                   int column)

The Constructor.

Method Detail

insert

public void insert(int row)

This scheme doesn't take any notice of insertions or removals.

remove

public void remove(int row)

This scheme doesn't take any notice of insertions or removals.

readFrom

public void readFrom(InputStream in)
              throws IOException

Reads the entire state of the scheme from the input stream. This is a trivial case for BlindSearch which doesn't require any data to be stored.

Specified by:

readFrom in class SelectableScheme

Throws:

IOException

writeTo

public void writeTo(OutputStream out)
             throws IOException

Writes the entire state of the scheme to the output stream. This is a trivial case for BlindSearch which doesn't require any data to be stored.

Specified by:

writeTo in class SelectableScheme

Throws:

IOException

copy

public SelectableScheme copy(TableDataSource table,
                             boolean immutable)

Returns an exact copy of this scheme including any optimization information. The copied scheme is identical to the original but does not share any parts. Modifying any part of the copied scheme will have no effect on the original and vice versa.

Specified by:

copy in class SelectableScheme

dispose

public void dispose()

Disposes and invalidates the BlindSearch.

Specified by:

dispose in class SelectableScheme

selectAll

public IntegerVector selectAll()

Description copied from class: SelectableScheme

These are the select operations that are the main purpose of the scheme. They retrieve the given information from the set. Different schemes will have varying performance on different types of data sets. The select operations must *always* return a resultant row set that is sorted from lowest to highest.

Overrides:

selectAll in class SelectableScheme

selectRange

public IntegerVector selectRange(SelectableRange range)

Description copied from class: SelectableScheme

Selects the given range of values from this index. The SelectableRange must contain a 'start' value that compares <= to the 'end' value.

This must guarentee that the returned set is sorted from lowest to highest value.

selectRange

public IntegerVector selectRange(SelectableRange[] ranges)

Description copied from class: SelectableScheme

Selects a set of ranges from this index. The ranges must not overlap and each range must contain a 'start' value that compares <= to the 'end' value. Every range in the array must represent a range that's lower than the preceeding range (if it exists).

If the above rules are enforced (as they must be) then this method will return a set that is sorted from lowest to highest value.

This must guarentee that the returned set is sorted from lowest to highest value.