Bulk.execute()
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Tip
Starting in version 3.2, MongoDB also provides the
db.collection.bulkWrite()
method for performing bulk
write operations.
Description
Bulk.execute()
Executes the list of operations built by the
Bulk()
operations builder.Bulk.execute()
accepts the following parameter:ParameterTypeDescriptionwriteConcern
documentOptional. 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 is{ w: 1 }
unless modified as part of the replica set configuration.See Override Default Write Concern for an example.
Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see Transactions and Write Concern.
Returns: A BulkWriteResult()
object that contains the status of the operation.After execution, you cannot re-execute the
Bulk()
object without reinitializing. Seedb.collection.initializeUnorderedBulkOp()
anddb.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.
Bulk()
operations and comparable methods in the drivers do not
have a limit for the number of operations in a group. To see how the
operations are grouped for 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.
Bulk()
operations and comparable methods in the drivers do not
have a limit for the number of operations in a group. To see how the
operations are grouped for bulk operation execution, call
Bulk.getOperations()
after the execution.
Transactions
Bulk()
can be used inside distributed transactions.
For Bulk.insert()
operations, the collection must already exist.
For Bulk.find.upsert()
, if the operation results in an
upsert, the collection must already exist.
Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see Transactions and Write Concern.
Important
In most cases, a distributed transaction incurs a greater performance cost over single document writes, and the availability of distributed transactions should not be a replacement for effective schema design. For many scenarios, the denormalized data model (embedded documents and arrays) will continue to be optimal for your data and use cases. That is, for many scenarios, modeling your data appropriately will minimize the need for distributed transactions.
For additional transactions usage considerations (such as runtime limit and oplog size limit), see also Production Considerations.
Examples
Execute Bulk Operations
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.initializeUnorderedBulkOp(); bulk.insert( { item: "abc123", status: "A", defaultQty: 500, points: 5 } ); bulk.insert( { item: "ijk123", status: "A", defaultQty: 100, points: 10 } ); bulk.execute( );
The operation returns the following BulkWriteResult()
object:
BulkWriteResult({ "writeErrors" : [ ], "writeConcernErrors" : [ ], "nInserted" : 2, "nUpserted" : 0, "nMatched" : 0, "nModified" : 0, "nRemoved" : 0, "upserted" : [ ] })
For details on the return object, see BulkWriteResult()
. For
details on the batches executed, see Bulk.getOperations()
.
Override Default Write Concern
The following operation to a replica set specifies a write
concern of "w: majority"
with a
wtimeout
of 5000 milliseconds such that the method returns after
the writes propagate to a majority of the voting replica set members or
the method times out after 5 seconds.
var bulk = db.items.initializeUnorderedBulkOp(); bulk.insert( { item: "efg123", status: "A", defaultQty: 100, points: 0 } ); bulk.insert( { item: "xyz123", status: "A", defaultQty: 100, points: 0 } ); bulk.execute( { w: "majority", wtimeout: 5000 } );
The operation returns the following BulkWriteResult()
object:
BulkWriteResult({ "writeErrors" : [ ], "writeConcernErrors" : [ ], "nInserted" : 2, "nUpserted" : 0, "nMatched" : 0, "nModified" : 0, "nRemoved" : 0, "upserted" : [ ] })