Working with Indexes

The GemFire Enterprise query engine supports indexing. By using indexes the performance of a query can be significantly improved. An index can provide significant performance gains for query execution. A query run without the aid of an index iterates through every object in the collection. If an index is available that matches part or all of the query specification, the query iterates only over the indexed set, and query processing time can be reduced.

A query run without the aid of an index iterates through every object in the collection. If an index is available that matches part or all of the query specification, the query iterates only over the indexed set, thus reducing query processing time.

When creating indexes, keep in mind the following:
  • Indexes incur maintenance costs as they must be updated when the indexed data changes. An index that requires many updates and is not used very often may require more system resources than no index at all.
  • Indexes consume memory.
  • Indexes have limited support on overflow regions. See Using Indexes with Overflow Regions for details.