Query Refinement (FAST Search Server 2010 for SharePoint)
Published: May 2010
Learn how you can use FAST Search Server 2010 for SharePoint query refinement features in queries and results.
Query refinement features provide the user with relevant refinement options for their queries. It enables the user to drill down into a query result by using aggregated statistical data computed for the query result. This is typically used for metadata associated with the indexed items, such as creation date, and author and person names that appear in the item. By using the refinement options, you can refine your query to present only items created throughout a certain time period, or display only terms that reference a specific person.
Applies to: Microsoft FAST Search Server 2010 for SharePoint
In this section:
FAST Search Server 2010 for SharePoint supports two kinds of query refinement, deep refinement and shallow refinement. They differ in how the refinement data is created. You configure the type of query refinement in the index schema. The query parameter syntax and result data format is similar.
Deep refinement is based on the aggregation of managed property statistics for all of the results of a search query. The indexer creates aggregation data that is used in the query matching process. The advantage of using this kind of query refinement is that the refinement options reflect all the items matching a query. This is the recommended mode in most cases, but defining many deep refiners will have a significant effect on memory usage in the query matching component.
Shallow refinement is based on the aggregation of managed property statistics for the top 50 results for a search query. The refinement result data is created during result processing and does not affect the performance of the query matching node. Because the refinement is limited to the top matching results, you may be unable to find results hidden deeper in the query results. However, this refinement option does not affect the indexing process and can therefore apply immediately after it has been enabled.