org.apache.geode.cache.query

Interface Index

public interface Index

An index that is built over the data stored in a GemFire Region.

For a description of the types of indexes that GemFire currently supports, see IndexType.

An index is specified using a name, indexedExpression, fromClause, and optionally a projectionAttributes.

The name uniquely identifies the index to for the statistics services in GemFire.

The indexedExpression is the lookup value for the index. The way that an indexedExpression is specified and used varies depending on the type of index. For more information, see IndexType.

The fromClause specifies the collection(s) of objects that the index ranges over, and must contain one and only one region path.

The optional projectAttributes specifies a tranformation that is done on the values and is used for pre-computing a corresponding projection as defined in a query.

Since:

GemFire 4.0

See Also:

QueryService.createIndex(String, IndexType, String, String), IndexType

Method Summary

Modifier and Type	Method and Description
String	getCanonicalizedFromClause() Get the canonicalized fromClause for this index.
String	getCanonicalizedIndexedExpression() Get the canonicalized indexedExpression for this index.
String	getCanonicalizedProjectionAttributes() Get the canonicalized projectionAttributes for this expression.
String	getFromClause() Get the original fromClause for this index.
String	getIndexedExpression() Get the original indexedExpression for this index.
String	getName() Returns the unique name of this index
String	getProjectionAttributes() Get the original projectionAttributes for this expression.
Region<?,?>	getRegion() The Region this index is on
IndexStatistics	getStatistics() Get statistics information for this index.
IndexType	getType() Get the index type
default boolean	isValid() Get whether index is valid to be used in queries.

Method Detail

getName

String getName()

Returns the unique name of this index

Returns:

the unique name of this index

getType

IndexType getType()

Get the index type

Returns:

the type of index

getRegion

Region<?,?> getRegion()

The Region this index is on

Returns:

the Region for this index

getStatistics

IndexStatistics getStatistics()

Get statistics information for this index.

Returns:

statistics information for this index

Throws:

UnsupportedOperationException - for indexes created on Maps. Example: Index on Maps with expression p['key'].
On Map type indexes the stats are created at individual key level that can be viewed in VSD stats.

getFromClause

String getFromClause()

Get the original fromClause for this index.

Returns:

the original fromClause for this index

isValid

default boolean isValid()

Get whether index is valid to be used in queries.

Returns:

whether index is valid to be used in queries

getCanonicalizedFromClause

String getCanonicalizedFromClause()

Get the canonicalized fromClause for this index.

Returns:

the canonicalized fromClause for this index

getIndexedExpression

String getIndexedExpression()

Get the original indexedExpression for this index.

Returns:

the original indexedExpression for this index

getCanonicalizedIndexedExpression

String getCanonicalizedIndexedExpression()

Get the canonicalized indexedExpression for this index.

Returns:

the canonicalized indexedExpression for this index

getProjectionAttributes

String getProjectionAttributes()

Get the original projectionAttributes for this expression.

Returns:

the projectionAttributes, or "*" if there were none specified at index creation.

getCanonicalizedProjectionAttributes

String getCanonicalizedProjectionAttributes()

Get the canonicalized projectionAttributes for this expression.

Returns:

the projectionAttributes, or "*" if there were none specified at index creation.