Package 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:

  • Method Details

    • 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.