Bulk()
Tip
MongoDB also provides the db.collection.bulkWrite() method for
performing bulk write operations.
Description
Bulk()Bulk operations builder used to construct a list of write operations to perform in bulk for a single collection. To instantiate the builder, use either the
db.collection.initializeOrderedBulkOp()or thedb.collection.initializeUnorderedBulkOp()method.
Ordered and Unordered Bulk Operations
The builder can construct the list of operations as ordered or unordered.
Ordered Operations
With an ordered operations list, MongoDB executes the write operations in the list serially. If an error occurs during the processing of one of the write operations, MongoDB will return without processing any remaining write operations in the list.
Use db.collection.initializeOrderedBulkOp() to create a
builder for an ordered list of write commands.
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 in mongosh 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
With an unordered operations list, MongoDB can execute in parallel, as well as in a nondeterministic order, the write operations in the list. If an error occurs during the processing of one of the write operations, MongoDB will continue to process remaining write operations in the list.
Use db.collection.initializeUnorderedBulkOp() to create a
builder for an unordered list of write commands.
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 in mongosh 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.
Methods
The Bulk() builder has the following methods:
Name | Description |
|---|---|
Adds an insert operation to a list of operations. | |
Specifies the query condition for an update or a remove operation. | |
Adds a multiple document delete operation to a list of operations. | |
Adds a single document delete operation to a list of operations. | |
An alias for Bulk.find.delete(). | |
An alias for Bulk.find.deleteOne(). | |
Adds a single document replacement operation to a list of operations. | |
Adds a single document update operation to a list of operations. | |
Adds a multi update operation to a list of operations. | |
Specifies upsert: true for an update operation. | |
Executes a list of operations in bulk. | |
Returns an array of write operations executed in the Bulk() operations object. | |
Returns a JSON document that contains the number of operations and batches in the Bulk() operations object. | |
Returns the Bulk.toJSON() results as a string. |