Optimizing Data Matching Performance
The following are recommendations for achieving good performance with data matching when working with large volumes of data:
- Work with a database administrator to verify that the table space is large enough to hold the records generated during the data matching process. - During the batch data matching process, the information on potential duplicate records is stored in the S_DEDUP_RESULT table as a pair of row IDs of the duplicate records and the match scores between them. The number of records in the results table S_DEDUP_RESULT can include up to six times the number of records in the base tables combined. Remember that: - If the base tables contain many duplicates, more records are inserted in the results table. 
- If different search types are used, a different set of duplicate records might be found and will be inserted into the results table. 
- If you use a low match threshold, the matching process generates more records to the results table. 
 
- Remove obsolete result records manually from the S_DEDUP_RESULT table by running SQL statements directly on this table. - When a duplicate record is detected, the information about the duplicate is automatically placed in the S_DEDUP_RESULT table, whether or not the same information exists in that table. Running multiple batch data matching tasks therefore results in a large number of duplicate records in the table. Therefore, it is recommended that you manually remove the existing records in the S_DEDUP_RESULT table before running a new batch data matching task. You can remove the records using any utility that allows you to submit SQL statements. Note: When truncating the S_DEDUP_RESULT table, all potential duplicate records found for all data matching business components are deleted.
- Match performance is slow when the SOH string is set as follows: - S_POSTN_CON.CON_LAST_NAME = 'SOH'- Setting the following values improves match performance: - Navigate to the Contact Business Component. 
- Add the following user property and value under the Last Name field: - User Property - Value - Sort Search Optimization - FALSE 
 
For more information about running batch data matching, see Matching Data Using Batch Jobs.