The query data cache allows data from previous searches to be cached, reducing the amount of disk access time for subsequent queries that use similar terms.For example, a user searches for java virtual machine; the data for each individual term is cached. When another user searches for java message queue, only the data for message and queue needs to be obtained from the indexes on the disk as the data for java is in the cache.Each document store manager has its own query data cache, which is shared by all the document stores managed by that document store manager. Use the Web administration page for each document store manager to manage the size of each query data cache. By default, each cache is set to 50MB. To improve query time increase the value, if the maximum JVM heap size permits, to 128MB, 256MB, or 512MB.