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## org.modeshape.jcr.query.lucene
Class LuceneQueryEngine.LuceneAccessQuery

    java.lang.Object
      org.modeshape.jcr.query.process.ProcessingComponent
          org.modeshape.jcr.query.process.AbstractAccessComponent
              org.modeshape.jcr.query.lucene.LuceneQueryEngine.LuceneAccessQuery

Enclosing class:
  LuceneQueryEngine

    protected static class LuceneQueryEngine.LuceneAccessQuery

extends AbstractAccessComponent

The component that is created to represent a single access query and, when executed, transforms that access query into a single Lucene query and issues it against Lucene.

Nested Class Summary

Nested classes/interfaces inherited from class org.modeshape.jcr.query.process.ProcessingComponent
`ProcessingComponent.DynamicOperation`

Field Summary

Fields inherited from class org.modeshape.jcr.query.process.AbstractAccessComponent
`accessNode, andedConstraints, limit, projectedColumns, sourceName`

Constructor Summary
`LuceneQueryEngine.LuceneAccessQuery(LuceneSchema schema, LuceneProcessingContext processingContext, QueryContext context, QueryResults.Columns resultColumns, PlanNode accessNode)`

Method Summary
`List<Object[]>` | `execute()` Execute this stage of processing and return the resulting tuples that each conform to the `columns`.

Methods inherited from class org.modeshape.jcr.query.process.ProcessingComponent
`close, createDynamicOperation, createSortComparator, emptyTuples, getColumns, getContext, problems`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### LuceneQueryEngine.LuceneAccessQuery

    public LuceneQueryEngine.LuceneAccessQuery(LuceneSchema schema,
                                               LuceneProcessingContext processingContext,
                                               QueryContext context,
                                               QueryResults.Columns resultColumns,
                                               PlanNode accessNode)

Method Detail

### execute

    public List<Object[]> execute()

  Execute this stage of processing and return the resulting tuples that each conform to the `columns`.

  Some kinds of constraints are not easily pushed down to Lucene as are of a Lucene Query, and instead are applied by filtering the results. For example, a `FullTextSearchScore` applies to the score of the tuple, which cannot be (easily?) applied as a `Lucene Query`.

  Therefore, each of the AND-ed constraints of the query are evaluated separately. After all, each of the tuples returned by the planned access query must satisfy all of the AND-ed constraints. Or, to put it another way, if a tuple does not satisfy one of the AND-ed constraints, the tuple should not be included in the query results.

  Logically, any AND-ed criteria that cannot be pushed down to Lucene can of course be applied as a filter on the results. Thus, each AND-ed constraint is processed to first determine if it can be represented as a Lucene query; all other AND-ed constraints must be handled as a results filter. Since most queries will likely use one or more simple constraints AND-ed together, this approach will likely work very well.

  The only hairy case is when any AND-ed constraint is actually an OR-ed combination of multiple constraints of which at least one cannot be pushed down to Lucene. In this case, the entire AND-ed constraint must be treated as a results filter (even if many of those constraints that make up the OR-ed constraint can be pushed down). Hopefully, this will not be a common case in actual queries.

  Specified by:
    `execute` in class `ProcessingComponent`
  Returns:
    the list of tuples, where each tuple corresonds to the `columns`; never null
  See Also:
    `ProcessingComponent.execute()`

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