Package com.yahoo.search.querytransform

Class SortingDegrader

java.lang.Object
com.yahoo.component.AbstractComponent
com.yahoo.component.chain.ChainedComponent
com.yahoo.processing.Processor
com.yahoo.search.Searcher
com.yahoo.search.querytransform.SortingDegrader
All Implemented Interfaces:
com.yahoo.component.Component, com.yahoo.component.Deconstructable, Comparable<com.yahoo.component.Component>
public class SortingDegrader extends Searcher
If the query is eligible, specify that the query should degrade if it causes too many hits to avoid excessively expensive queries.

Queries are eligible if they do sorting, don't do grouping, and the first sort criteria is a fast-search attribute.

Author:
bratseth

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final com.yahoo.processing.request.CompoundName
    DEGRADING
    Set this to false in query.properties to turn off degrading.
    static final com.yahoo.processing.request.CompoundName
    PAGINATION
     

    Fields inherited from class com.yahoo.component.AbstractComponent

    isDeconstructable

  • Constructor Summary

    Constructors
    Constructor
    Description
    SortingDegrader()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    Result
    search(Query query, Execution execution)
    Override this to implement your searcher.

    Methods inherited from class com.yahoo.search.Searcher

    ensureFilled, fill, getLogger, process, toString

    Methods inherited from class com.yahoo.component.chain.ChainedComponent

    getAnnotatedDependencies, getDefaultAnnotatedDependencies, getDependencies, initDependencies

    Methods inherited from class com.yahoo.component.AbstractComponent

    clone, compareTo, deconstruct, getClassName, getId, getIdString, hasInitializedId, initId, isDeconstructable, setIsDeconstructable

    Methods inherited from class java.lang.Object

    equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • DEGRADING

      public static final com.yahoo.processing.request.CompoundName DEGRADING
      Set this to false in query.properties to turn off degrading. Default: on

    • PAGINATION

      public static final com.yahoo.processing.request.CompoundName PAGINATION

  • Constructor Details

    • SortingDegrader

      public SortingDegrader()

  • Method Details

    • search

      public Result search(Query query, Execution execution)
      Description copied from class: Searcher
      Override this to implement your searcher.

      Searcher implementation subclasses will, depending on their type of logic, do one of the following:

      • Query processors: Access the query, then call execution.search and return the result
      • Result processors: Call execution.search to get the result, access it and return
      • Sources (which produces results): Create a result, add the desired hits and return it.
      • Federators (which forwards the search to multiple subchains): Call search on the desired subchains in parallel and get the results. Combine the results to one and return it.
      • Workflows: Call execution.search as many times as desired, using different queries. Eventually return a result.

      Hits come in two kinds - concrete hits are actual content of the kind requested by the user, meta hits are hits which provides information about the collection of hits, on the query, the service and so on.

      The query specifies a window into a larger result list that must be returned from the searcher through hits and offset; Searchers which returns list of hits in the top level in the result must return at least hits number of hits (or if impossible; all that are available), starting at the given offset. In addition, searchers are allowed to return any number of meta hits (although this number is expected to be low). For hits contained in nested hit groups, the concept of a window defined by hits and offset is not well defined and does not apply.

      Error handling in searchers:

      • Unexpected events: Throw any RuntimeException. This query will fail with the exception message, and the error will be logged
      • Expected events: Create (new Result(Query, ErrorMessage) or add result.setErrorIfNoOtherErrors(ErrorMessage) an error message to the Result.
      • Recoverable user errors: Add a FeedbackHit explaining the condition and how to correct it.
      Specified by:
      search in class Searcher
      Parameters:
      query - the query
      Returns:
      the result of making this query