Product Documentation : Ehcache Developer Guide : Searching a Cache : Best Practices for Optimizing Searches
Best Practices for Optimizing Searches
*Construct searches by including only the data that is actually required.
*Only use includeKeys( ) and/or includeAttribute( ) if those values are required for your application logic.
*If you do not need values or attributes, be careful not to burden your queries with unnecessary work. For example, if result.getValue( ) is not called in the search results, do not use includeValues( ) in the query.
*Consider if it would be sufficient to get attributes or keys on demand. For example, instead of running a search query with includeValues( ) and then result.getValue( ), run the query for keys and include cache.get( ) for each individual key.
The includeKeys( ) and includeValues( ) methods have lazy deserialization, meaning that keys and values are deserialized only when result.getKey( ) or result.getValue( ) is called. However, calls to includeKeys() and includeValues( ) do take time, so consider carefully when constructing your queries.
*Searchable keys and values are automatically indexed by default. If you are not including them in your query, turn off automatic indexing with the following:
<cache name="cacheName" ...>
<searchable keys="false" values="false"/>
*Limit the size of the result set. Depending on your use case, you might consider maxResults, an Aggregator, or pagination:
*If getting a subset of all the possible results quickly is more important than receiving all the results, consider using query.maxResults(int number_of_results). Sometimes maxResults is useful where the result set is ordered such that the items you want most are included within the maxResults.
*If all you want is a summary statistic, use a built-in Aggregator function, such as count(). For details, see the package in the Ehcache Javadoc.
*Make your search as specific as possible.
*Queries with iLike criteria and fuzzy (wildcard) searches might take longer than more specific queries.
*If you are using a wildcard, try making it the trailing part of the string instead of the leading part ("321*" instead of "*123").
If you want leading wildcard searches, you should create a <searchAttribute> with the string value reversed in it, so that your query can use the trailing wildcard instead.
*When possible, use the query criteria “Between” instead of “LessThan” and “GreaterThan”, or “LessThanOrEqual” and “GreaterThanOrEqual”. For example, instead of using le(startDate) and ge(endDate), try not(between(startDate,endDate)).
*Index dates as integers. This can save time and can also be faster if you have to do a conversion later on.
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