12.3. About Querying in Red Hat JBoss Data Grid

Users have the ability to query the entire stored data set for specific items in Red Hat JBoss Data Grid. Applications may not always be aware of specific keys, however different parts of a value can be queried using the Query Module.

The JBoss Data Grid Query Module utilizes the capabilities of Hibernate Search and Apache Lucene to index and search objects in the cache. This allows objects to be located within the cache based on their properties, rather than requiring the keys for each object.

Objects can be searched for based on some of their properties. For example:

An exact data match can also be implemented with the MapReduce function, however full text and relevance based scoring can only be performed via the Query Module.

In order to perform querying on the entire data set stored in the distributed grid, Red Hat JBoss Data Grid utilizes the capabilities of the Apache Lucene indexing tool, as well as Hibernate Search.

In JBoss Data Grid, the Query Module indexes keys and values annotated with Hibernate Search indexing annotations, then updates the index based in Apache Lucene accordingly.

Hibernate Search intercepts changes to entries stored in the data grid to generate corresponding indexing operations