System Administration
The Search Threshold is used when users perform a search on a page. In contrast, the Duplicate Detection Threshold is used when searching the index for duplicate records.
If the duplicate detection process finds a match for a record whose quality is below the cut-off threshold (expressed as a percentage value), the match is not stored in the #Duplicate table.
Both are set on the Index Specifications page. Refer to Configure an Index for more information about setting thresholds.
In general, the Duplicate Detection Threshold should be set higher than the Search Threshold. The higher the number, the less likely false positives display. The fewer false positives, the more accurate the results are.
The number of columns used to construct the Duplicate Detection search string should affect the threshold setting. If Duplicate Detection has been enabled on one or two columns, then the default value of 50.00% is appropriate. The more columns searched, the longer the search string and the lower the threshold setting. If Duplicate Detection has been enabled on five columns, a rank of 20.00% may be more effective.
The number of words used to construct the duplicate detection search string affects the Duplicate Detection Threshold. If duplicate detection is enabled on five columns, but three of the columns are usually NULL when the record is created, then the default value of 50.00% may still be effective. In contrast, if duplicate detection is enabled on two columns that normally contain ten words each, then the lower value may be necessary.
