Wildcard Search

You can use wildcards in IDOL Server to find terms that are similar to the search term. In wildcard search, a question mark (?) represents a single missing character, and an asterisk (*) represents any number of missing characters.

Wildcard searches might be useful if you have disabled Stemming, for example for legal search scenarios where the search must find only exact terms, but you want to find a more general term in one case. You can also use wildcards in some situations where stemming does not capture the similarity between two terms.

Micro Focus recommends that you use wildcard searches sparingly in IDOL Server, because they can have a large impact on query speeds. Advanced Search mode allows you to search for exact or stemmed terms, and this method is usually faster and more efficient. You can also use a stemming file to specify custom stemming in certain situations.

Wildcard Search Process

When IDOL Server receives a wildcard query, it removes stop words, and stems the whole terms as usual. Then it expands each term that contains a wildcard to a list of terms that IDOL Server contains that match the wildcard.

When it expands a wildcard, IDOL Server finds all the exact (unstemmed) terms in the index that match the wildcard. If the wildcard is not very specific, or if you have a large number of terms in the unstemmed index, this process can take a long time.

After it expands the wildcard to all the unstemmed terms, IDOL Server retrieves all the documents that contain these terms, in addition to any other terms in the query.