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// Check explain results when an in order plan is selected among mixed in order and out of order
// plans.
t = db.jstests_explaina;
t.drop();
t.ensureIndex( { a:1 } );
t.ensureIndex( { b:1 } );
for( i = 0; i < 1000; ++i ) {
t.save( { a:i, b:i%3 } );
}
// Query with an initial set of documents.
explain1 = t.find( { a:{ $gte:0 }, b:2 } ).sort( { a:1 } ).explain( true );
for( i = 1000; i < 2000; ++i ) {
t.save( { a:i, b:i%3 } );
}
// Query with some additional documents.
explain2 = t.find( { a:{ $gte:0 }, b:2 } ).sort( { a:1 } ).explain( true );
function plan( explain, cursor ) {
for( i in explain.allPlans ) {
e = explain.allPlans[ i ];
if ( e.cursor == cursor ) {
return e;
}
}
assert( false );
}
// Check query totals.
assert.eq( 333, explain1.n );
assert.eq( 666, explain2.n );
// Check totals for the selected in order a:1 plan.
assert.eq( 333, plan( explain1, "BtreeCursor a_1" ).n );
assert.eq( 1000, plan( explain1, "BtreeCursor a_1" ).nscanned );
assert.eq( 666, plan( explain2, "BtreeCursor a_1" ).n );
assert.eq( 2000, plan( explain2, "BtreeCursor a_1" ).nscanned );
// Check that results only examined after the a:1 plan is selected will not affect plan explain
// output for other plans.
assert.eq( plan( explain1, "BtreeCursor b_1" ), plan( explain2, "BtreeCursor b_1" ) );
assert.eq( plan( explain1, "BasicCursor" ), plan( explain2, "BasicCursor" ) );
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