Db2 Text Search queue memory size

The queue memory size for Db2 Text Search must be set properly for optimal index update processing. Queue memory assignment can be controlled both for the database and for the text server.

The database queue memory determines the number of documents that can be sent to the text server for update processing at any time. To control the size of the database queue memory, update the SYSIBMTS.TSDEFAULTS administration view and set the value for the DocumentResultQueueSize parameter. The default value is 10,000. This value is used to limit how much database memory is reserved per update operation for a collection. Note that on a multi-partition setup, a single text index update that is configured for parallel execution will reserve memory space for each collection that needs an update.

The second mechanism for queue memory control applies to the text server. Two configuration values determine the use of queue memory.

• inputQueueMemorySize:
  Specifies the memory size of the input queue on the indexing server. The input queue contains documents that are waiting for preprocessing. A larger memory size will be faster, but will consume more resources. The default size is 15 MB.
• outputQueueMemorySize:
  Specifies the memory size of the output queue on the indexing server. The output queue contains documents that are waiting to be indexed after preprocessing. A larger memory size will be faster, but will consume more resources. The default size is 15 MB.

Consider the ratio between the input and output queue's memory size and the heap memory. The queue size is determined by the memory consumption of the documents in the queue. If you intend to process long documents, for example 20 MB each, consider increasing the queue memory size and increasing the heap size.

configTool configureParams -configPath <full-path-to-configuration-folder>
 -inputQueueMemorySize <value>