Db2 Text Search index source characteristics

To enhance performance during indexing or search, use the following techniques:

• For primary key columns, use numeric data types, such as INTEGER, instead of a VARCHAR type. Avoid primary keys that are a compound of multiple VARCHAR columns to minimize traffic for query results.
• Ensure that your system has enough real memory available for the index update operation. Index updates require memory that is in addition to that required for any database buffer pools. If there is insufficient memory, the operating system uses paging space instead which decreases search performance considerably. For more information, see Db2 Text Search capacity planning and optimization.
• If large numbers of small documents must be processed in text search server index updates, consider reducing the number of parallel index updates and instead increase the queue sizes to increase the maximum flow of documents to the text server. See the capacity planning topics for details.
• Ensure that the content to be indexed is accessible and of proper format, as the performance might decrease during an index update if many error and warning messages are written to the event table.