Adding filter to large data sets in Voyager Advanced and Builder searches returns fewer results than expected or no results

Question

In WebVoyage Advanced Search when adding a filter to an initial keyword search that results in tens of thousands of records, the filter (for example, Year Range) produces "no hits" even though we know there should be records in the set.

Answer

When you do a search for a broad term, such as "Washington" or "Canada", which results in tens of thousands of records, the system will truncate the result set before applying any limits.

In other words, the volume of records is too large for the date limit to be effective.

This behavior is by design and is a known behavior that results from the keyword server algorithm. This behavior applies both to the WebVoyage Advanced Search and Cataloging Client Builder tab.

Additional Information

Example:
keyword search for "america" limited by location, date and/or other applicable limits

1. In WebVoyage Advanced Search do keyword search for "america" using default settings of "keyword anywhere" and "any of these" or "all of these"
2. Initial result will be truncated at first 10,000 records matching the keyword
3. Add filter for Year range of 1800-1900
4. Results for the filter will be limited to the first 10,000 records (the truncated record set) and may in fact produce no results ("no hits").

Explanation: if your result set for "america" is large enough, and contains, say, the newest records to be added to the database, then you might have no records in the truncated set which would be included by the filter looking at "old" records.

See also: KEYSVR:not retrieving all results in large data sets

• Article last edited: 13-Feb-2020