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Diffstat (limited to 'jstests/sharding/limit_push.js')
-rw-r--r-- | jstests/sharding/limit_push.js | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/jstests/sharding/limit_push.js b/jstests/sharding/limit_push.js new file mode 100644 index 0000000..75ad271 --- /dev/null +++ b/jstests/sharding/limit_push.js @@ -0,0 +1,47 @@ +// This test is to ensure that limit() clauses are pushed down to the shards and evaluated +// See: http://jira.mongodb.org/browse/SERVER-1896 + +s = new ShardingTest( "limit_push", 2, 1, 1 ); + +db = s.getDB( "test" ); + +// Create some data +for (i=0; i < 100; i++) { db.limit_push.insert({ _id : i, x: i}); } +db.limit_push.ensureIndex( { x : 1 } ); +assert.eq( 100 , db.limit_push.find().length() , "Incorrect number of documents" ); + +// Shard the collection +s.adminCommand( { enablesharding : "test" } ); +s.adminCommand( { shardcollection : "test.limit_push" , key : { x : 1 } } ); + +// Now split the and move the data between the shards +s.adminCommand( { split : "test.limit_push", middle : { x : 50 }} ); +s.adminCommand( { moveChunk: "test.limit_push", find : { x : 51}, to : "shard0000" }) + +// Check that the chunck have split correctly +assert.eq( 2 , s.config.chunks.count() , "wrong number of chunks"); + +// The query is asking for the maximum value below a given value +// db.limit_push.find( { x : { $lt : 60} } ).sort( { x:-1} ).limit(1) +q = { x : { $lt : 60} }; + +// Make sure the basic queries are correct +assert.eq( 60 , db.limit_push.find( q ).count() , "Did not find 60 documents" ); +//rs = db.limit_push.find( q ).sort( { x:-1} ).limit(1) +//assert.eq( rs , { _id : "1" , x : 59 } , "Did not find document with value 59" ); + +// Now make sure that the explain shos that each shard is returning a single document as indicated +// by the "n" element for each shard +exp = db.limit_push.find( q ).sort( { x:-1} ).limit(1).explain(); +printjson( exp ) + +assert.eq("ParallelSort", exp.clusteredType, "Not a ParallelSort"); + +var k = 0; +for (var j in exp.shards) { + assert.eq( 1 , exp.shards[j][0].n, "'n' is not 1 from shard000" + k.toString()); + k++ +} + +s.stop(); + |