Bulk()

Ordered Operations有序操作

With an ordered operations list, MongoDB executes the write operations in the list serially. 在有序操作列表中，MongoDB串行执行列表中的写入操作。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.如果在处理其中一个写入操作期间发生错误，MongoDB将返回，而不处理列表中的任何剩余写入操作。

Use db.collection.initializeOrderedBulkOp() to create a builder for an ordered list of write commands.使用db.collection.initializeOrderedBulkOp()为写入命令的有序列表创建生成器。

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. 当执行有序的操作列表时，MongoDB根据操作类型和连续性对操作进行分组；即，将相同类型的连续操作分组在一起。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. 例如，如果一个有序列表有两个插入操作，随后是一个更新操作，然后是另一个插入操作。MongoDB将这些操作分为三个单独的组：第一组包含两个插入作业，第二组包含更新作业，第三组包含最后一个插入作业。This behavior is subject to change in future versions.此行为可能会在将来的版本中更改。

Bulk() operations in mongosh and comparable methods in the drivers do not have a limit for the number of operations in a group. mongosh中的Bulk()操作和驱动程序中的类似方法对组中的操作数量没有限制。To see how the operations are grouped for bulk operation execution, call Bulk.getOperations() after the execution.要查看操作如何分组以执行批量操作，请在执行后调用Bulk.getOperations()。

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.在分片集合上执行有序操作列表通常比执行无序列表慢，因为对于有序列表，每个操作都必须等待上一个操作完成。

Unordered Operations无序操作

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.使用无序操作列表，MongoDB可以并行执行列表中的写入操作，也可以以不确定的顺序执行。如果在处理其中一个写入操作期间发生错误，MongoDB将继续处理列表中剩余的写入操作。

Use db.collection.initializeUnorderedBulkOp() to create a builder for an unordered list of write commands.使用db.collection.initializeUnorderedBulkOp()为写命令的无序列表创建生成器。

When executing an unordered list of operations, MongoDB groups the operations. 在执行无序操作列表时，MongoDB会对操作进行分组。With an unordered bulk operation, the operations in the list may be reordered to increase performance. 对于无序批量操作，可以对列表中的操作重新排序以提高性能。As such, applications should not depend on the ordering when performing unordered bulk operations.因此，应用程序在执行无序批量操作时不应依赖于顺序。

Bulk() operations in mongosh and comparable methods in the drivers do not have a limit for the number of operations in a group. mongosh中的Bulk()操作和驱动程序中的类似方法对组中的操作数量没有限制。To see how the operations are grouped for bulk operation execution, call Bulk.getOperations() after the execution.要查看操作如何分组以执行批量操作，请在执行后调用Bulk.getOperations()。

Transactions事务

Bulk() can be used inside multi-document transactions.<Bulk()可以在多文档事务中使用。

For Bulk.insert() operations, the collection must already exist.对于Bulk.insert()操作，集合必须已经存在。

For Bulk.find.upsert(), if the operation results in an upsert, the collection must already exist.对于Bulk.find.upsert()，如果操作导致upsert，则集合必须已经存在。

Do not explicitly set the write concern for the operation if run in a transaction. 如果在事务中运行，请不要显式设置操作的写入关注点。To use write concern with transactions, see Transactions and Write Concern.要将写关注点用于事务，请参阅事务和写关注点。