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  1. Core Server
  2. SERVER-5581

assertion when clearing the query pattern for an unsatisfiable query (2.0 only, already fixed in 2.1)

    • Type: Icon: Bug Bug
    • Resolution: Done
    • Priority: Icon: Major - P3 Major - P3
    • 2.0.6
    • Affects Version/s: 2.0.4
    • Component/s: None
    • None
    • ALL

      If an attempt is made to clear the recorded index for the query plan of an unsatisfiable query, an assertion is raised because in 2.0 a query pattern cannot be generated for an unsatisfiable query.

      In 2.1 a query pattern can be generated for an unsatisfiable query, so the issue no longer exists in 2.1.

      t = db.t;
      t.drop();
      
      t.ensureIndex( { a:1 } );
      t.ensureIndex( { b:1 } );
      
      for( i = 0; i < 25; ++i ) {
          t.save( { a:0, b:'' } );
      }
      big = new Array( 1000000 ).toString();
      for( i = 0; i < 50; ++i ) {
          t.save( { a:[1,3], b:big } );
      }
      
      // Record the a:1 index for the query pattern for { a: { $lt:1 } }, { b:1 }.                      
      assert.eq( 'BtreeCursor a_1', t.find( { a:{ $lt:1 } } ).sort( { b:1 } ).explain().cursor );
      
      // The multikey query pattern for this query will match that of the previous query.               
      // The a:1 index will be retried for this query but fail because an in memory sort must           
      // be performed on a larger data set.  This causes the single key query pattern for               
      // { a:{ $lt:2, $gt:2 } }, { b:1 } to be cleared.                                                 
      assert.lt( -1, t.find( { a:{ $lt:2, $gt:2 } } ).sort( { b:1 } ).itcount() );
      

            Assignee:
            aaron Aaron Staple
            Reporter:
            aaron Aaron Staple
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              Created:
              Updated:
              Resolved: