Bulk.execute()¶

Description¶

Bulk.execute()¶

2.6 新版功能.

Executes the list of operations built by the Bulk() operations builder.

Bulk.execute() accepts the following parameter:

Parameter	Type	Description
`writeConcern`	document	Optional. Write concern document for the bulk operation as a whole. Omit to use default. For a standalone `mongod` server, the write concern defaults to `{ w: 1 }`. With a replica set, the default write concern for a `mongod` server is set as a replica set configuration option.

返回:	A `BulkWriteResult` object that contains the status of the operation.

After execution, you cannot re-execute the Bulk() object without reinitializing. See db.collection.initializeUnorderedBulkOp() and db.collection.initializeOrderedBulkOp().

Behavior¶

Ordered Operations¶

When executing an ordered list of operations, MongoDB groups the operations by the operation type and contiguity; i.e. contiguous operations of the same type are grouped together. For example, if an ordered list has two insert operations followed by an update operation followed by another insert operation, MongoDB groups the operations into three separate groups: first group contains the two insert operations, second group contains the update operation, and the third group contains the last insert operation. This behavior is subject to change in future versions.

Each group of operations can have at most 1000 operations. If a group exceeds this limit, MongoDB will divide the group into smaller groups of 1000 or less. For example, if the bulk operations list consists of 2000 insert operations, MongoDB creates 2 groups, each with 1000 operations.

The sizes and grouping mechanics are internal performance details and are subject to change in future versions.

To see how the operations are grouped for a bulk operation execution, call Bulk.getOperations() after the execution.

Executing an ordered list of operations on a sharded collection will generally be slower than executing an unordered list since with an ordered list, each operation must wait for the previous operation to finish.

Unordered Operations¶

When executing an unordered list of operations, MongoDB groups the operations. With an unordered bulk operation, the operations in the list may be reordered to increase performance. As such, applications should not depend on the ordering when performing unordered bulk operations.

Each group of operations can have at most 1000 operations. If a group exceeds this limit, MongoDB will divide the group into smaller groups of 1000 or less. For example, if the bulk operations list consists of 2000 insert operations, MongoDB creates 2 groups, each with 1000 operations.

The sizes and grouping mechanics are internal performance details and are subject to change in future versions.

To see how the operations are grouped for a bulk operation execution, call Bulk.getOperations() after the execution.

Example¶

The following initializes a Bulk() operations builder on the items collection, adds a series of insert operations, and executes the operations:

var bulk = db.items.initializeOrderedBulkOp();
bulk.insert( { item: "abc123", status: "A", defaultQty: 500, points: 5 } );
bulk.insert( { item: "ijk123", status: "A", defaultQty: 100, points: 10 } );
bulk.find( { status: "D" } ).removeOne();
bulk.find( { status: "D" } ).update( { $set: { points: 0 } } );
bulk.execute();

The operation returns the following BulkWriteResult() object:

BulkWriteResult({
   "writeErrors" : [ ],
   "writeConcernErrors" : [ ],
   "nInserted" : 2,
   "nUpserted" : 0,
   "nMatched" : 3,
   "nModified" : 3,
   "nRemoved" : 1,
   "upserted" : [ ]
})

For details on the return object, see BulkWriteResult(). For details on the batches executed, see Bulk.getOperations().

See

Bulk() for a listing of methods available for bulk operations.

← Bulk.find.upsert() Bulk.getOperations() →