Question

When a search matches tens of thousands of records, and same search is limited, why does search return fewer results than similar left-anchored search?

Answer

When conduct a keyword search, a set of results matching the search term(s) is returned. If set is very large (tens of thousands of records), not all matching results will be returned in initial set. This initial result set is then limited by the index searched, and any other limits applied (location, type, etc.). Because of the logic governing the keyword search, some matching results may not be returned in final set.

See examples in Additional Information for illustration of how this logic works in the client.

Additional Information

Example 1
keyword search for "blu?" on a keyword index for 245 |a 

1. Initial result set consists of the first 10,000 records matching keywords beginning with "blu?" anywhere in record.
2. Search logic then discards any keyword results that do not occur in a 245 |a
3. Displays resulting limited set in client.

If there are 564 records that match this criteria, and the initial set of 10,000 records includes 476, then when the logic in step 2 is applied, the final result set will be the 476 records that match both the keyword & index that were returned in the initial set.

Example 2
keyword search for "blu?" limited by location, date and/or other applicable limits

1. Initial result set consists of the first 10,000 records matching keywords beginning with "blu?" anywhere in record
2. Search logic then discards any results from set that do not match the limit(s) selected
3. Displays resulting limited set in client.

If there are 234 total records that match both the keyword & limit criteria, and the initial result set returns 213 of these, then when the limit is applied to the initial set of 10,000 records, the final result set will contain the 213 records matching both the keyword and limit criteria that were returned in the initial result set.

See Also: 

• Adding filter to large data sets in Voyager Advanced and Builder searches returns fewer results than expected or no results
• Voyager combined BIB keyword (e.g., GKEY) and MFHD keyword search does not return all results for large result sets

• Article last edited: 2/5/2014