Query Refinement
* Query refinement enables you to refine a query result by using aggregated statistical data that is computed for the query result. This is typically used for metadata associated with the indexed items, such as creation date, author, and person names appearing in the item.
* By using the refinement options, you can refine your query to only present items created throughout a certain time period, or only display items referencing a given person.
* FAST Search Server 2010 for SharePoint supports two kinds of query refiners:
Deep refiners : The query 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 query matching process. The advantage of using this query refiner type is that the refinement options will reflect all the items matching a query. This is usually the recommended mode, but defining many deep refiners may have a significant effect on memory usage in the query matching component.
Consider setting the RefinementType property to LatentRefinement if you want to prepare the index data structures for deep refinement, but do not want to enable the feature yet for query evaluation. When using this option, the required data structures for deep refinement are not loaded into main memory, and it will therefore have no performance effect on the query evaluation. The setting can later be changed to DeepRefinementEnabled to enable the feature. In that case, the change has an immediate effect (no requirement to re-index items).
Shallow refiners : The query 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. 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.
Shallow refiners have a significant performance effect on the query processing node and reduce the query performance.
A number of query refinement options can be specified both in the index schema and at query time. For more information about the query time options, see Specifying Refiners in a Query.
For Datetime managed properties, it is convenient to control binning of the refiners at query time instead of using the schema properties. This enables you to more easily specify binning on date boundaries. For more information, see Specifying Refiners in a Query.
* By using the refinement options, you can refine your query to only present items created throughout a certain time period, or only display items referencing a given person.
* FAST Search Server 2010 for SharePoint supports two kinds of query refiners:
Deep refiners : The query 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 query matching process. The advantage of using this query refiner type is that the refinement options will reflect all the items matching a query. This is usually the recommended mode, but defining many deep refiners may have a significant effect on memory usage in the query matching component.
Consider setting the RefinementType property to LatentRefinement if you want to prepare the index data structures for deep refinement, but do not want to enable the feature yet for query evaluation. When using this option, the required data structures for deep refinement are not loaded into main memory, and it will therefore have no performance effect on the query evaluation. The setting can later be changed to DeepRefinementEnabled to enable the feature. In that case, the change has an immediate effect (no requirement to re-index items).
Shallow refiners : The query 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. 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.
Shallow refiners have a significant performance effect on the query processing node and reduce the query performance.
A number of query refinement options can be specified both in the index schema and at query time. For more information about the query time options, see Specifying Refiners in a Query.
For Datetime managed properties, it is convenient to control binning of the refiners at query time instead of using the schema properties. This enables you to more easily specify binning on date boundaries. For more information, see Specifying Refiners in a Query.
Query refinement related interfaces:
| Interface | Description | ||
|---|---|---|---|
| RefinerConfiguration | Specifies a query refinement. | ||
| ManagedProperty |
Managed properties are metadata that can be searched or retrieved in query results. You can associate query refinement with a managed property by setting the ManagedProperty.RefinementEnabled property to True. This activates the associated RefinerConfiguration object for the managed property. You can modify the RefinerConfiguration by using the ManagedProperty.GetRefinerConfiguration method and the ManagedProperty.SetRefinerConfiguration method.
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