Wildcard search

The MDEX Engine uses a mechanism for wildcard search that simplifies user configuration. In most cases, the size of the on-disk index is reduced considerably, and indexing performance is improved compared with previous releases. This topic provides recommendations for optimizing your wildcard search performance.

To optimize performance of wildcard search, use the following recommendations:

Account for increased time needed for indexing. In general, if wildcard search is enabled in the MDEX Engine (even if it is not used by the users), it increases the time and disk space required for indexing. Therefore, consider first the business requirements for your Endeca application to decide whether you need to use wildcard search.
Note: To optimize performance, the MDEX Engine performs wildcard indexing for words that are shorter than 1024 characters. Words that are longer than 1024 characters are not indexed for wildcard search.
Do not use "low information" queries. For optimal performance, Endeca recommends using wildcard search queries with at least 2-3 non-wildcarded characters in them, such as abc* and ab*de. Avoid wildcard searches with one non-wildcarded character, such as a*, since they are more expensive to process. Also be aware that the MDEX Engine ignores queries that contain only wildcards, such as *. Similarly, wildcard queries that contain only punctuation symbols, spaces and wildcards, such as *., *', or * *, are ignored.
Analyze the format of your typical wildcard query cases. This lets you be aware of performance implications associated with one specific wildcard search pattern. Examine your queries to identify whether you have queries that contain punctuation syntax in between strings of text, such as ab*c.def*. For strings with punctuation, the MDEX Engine generates lists of words that match each of the punctuation-separated wildcard expressions. In this case, the MDEX Engine uses the --wildcard_max <count> setting to optimize its performance. This setting does not affect wildcard searches for strings which do not contain punctuation.

You enable wildcard search in Developer Studio.