com.hazelcast.query.impl

Interface Index

All Known Implementing Classes:

IndexImpl

public interface Index

Represents an index built on top of the attribute of the map entries.

Method Summary

Modifier and Type	Method and Description
void	clear() Clears out all entries from this index.
void	destroy() Releases all resources hold by this index, e.g.
String	getAttributeName()
TypeConverter	getConverter()
Set<QueryableEntry>	getRecords(Comparable value) Produces a result set containing entries whose attribute values are equal to the given value.
Set<QueryableEntry>	getRecords(Comparable[] values) Produces a result set containing entries whose attribute values are equal to at least one of the given values.
Set<QueryableEntry>	getSubRecords(ComparisonType comparisonType, Comparable searchedValue) Produces a result set containing entries whose attribute values are satisfy the comparison of the given type with the given value.
Set<QueryableEntry>	getSubRecordsBetween(Comparable from, Comparable to) Produces a result set by performing a range query on this index.
boolean	isOrdered() Tells whether this index is ordered or not.
void	removeEntryIndex(Data key, Object value) Removes the entry having the given key and the value from this index.
void	saveEntryIndex(QueryableEntry entry, Object oldValue) Saves the given entry into this index.

Method Detail

getAttributeName

String getAttributeName()

Returns:

the name of the attribute for which this index is built.

isOrdered

boolean isOrdered()

Tells whether this index is ordered or not.

Ordered indexes support the fast evaluation of range queries. Unordered indexes are still capable to execute range queries, but the performance would be about the same as the full scan performance.

Returns:

true if this index is ordered, false otherwise.

See Also:

getSubRecords(com.hazelcast.query.impl.ComparisonType, java.lang.Comparable), getSubRecordsBetween(java.lang.Comparable, java.lang.Comparable)

saveEntryIndex

void saveEntryIndex(QueryableEntry entry,
                    Object oldValue)

Saves the given entry into this index.

Parameters:

entry - the entry to save.

oldValue - the previous old value associated with the entry or null if the entry is new.

Throws:

QueryException - if there were errors while extracting the attribute value from the entry.

removeEntryIndex

void removeEntryIndex(Data key,
                      Object value)

Removes the entry having the given key and the value from this index.

Parameters:

key - the key of the entry to remove.

value - the value of the entry to remove.

Throws:

QueryException - if there were errors while extracting the attribute value from the entry.

getConverter

TypeConverter getConverter()

Returns:

the converter associated with this index; or null if the converter is not known because there were no saves to this index and the attribute type is not inferred yet.

getRecords

Set<QueryableEntry> getRecords(Comparable value)

Produces a result set containing entries whose attribute values are equal to the given value.

Parameters:

value - the value to compare against.

Returns:

the produced result set.

getRecords

Set<QueryableEntry> getRecords(Comparable[] values)

Produces a result set containing entries whose attribute values are equal to at least one of the given values.

Parameters:

values - the values to compare against.

Returns:

the produced result set.

getSubRecordsBetween

Set<QueryableEntry> getSubRecordsBetween(Comparable from,
                                         Comparable to)

Produces a result set by performing a range query on this index.

More precisely, this method produces a result set containing entries whose attribute values are greater than or equal to the given from value and less than or equal to the given to value.

Parameters:

from - the beginning of the range (inclusive).

to - the end of the range (inclusive).

Returns:

the produced result set.

getSubRecords

Set<QueryableEntry> getSubRecords(ComparisonType comparisonType,
                                  Comparable searchedValue)

Produces a result set containing entries whose attribute values are satisfy the comparison of the given type with the given value.

Parameters:

comparisonType - the type of the comparison to perform.

searchedValue - the value to compare against.

Returns:

the produced result set.

clear

void clear()

Clears out all entries from this index.

destroy

void destroy()

Releases all resources hold by this index, e.g. the allocated native memory for the HD index.