Bulk()

Ordered Operations有序操作

With an ordered operations list, MongoDB executes the write operations in the list serially. 通过一个有序的操作列表，MongoDB可以串行执行列表中的写操作。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操作的过程中发生错误，MongoDB将返回，而不处理列表中任何剩余的写操作。

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. 当执行一个有序的操作列表时，MongoDB会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、一个更新操作和另一个插入操作，MongoDB会将这些操作分为三个单独的组：第一组包含两个插入运算，第二组包含更新运算，第三组包含最后一个插入运算。This behavior is subject to change in future versions.此行为可能在未来版本中发生更改。

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.要查看如何为批量操作执行对操作进行分组，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操作列表慢，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，也可以按不确定的顺序执行。如果在处理其中一个写操作的过程中发生错误，MongoDB将继续处理列表中剩余的写操作。

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

When executing an unordered list of operations, MongoDB groups the operations. 当执行一个无序的操作列表时，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. 对于无序的批量操作，可以对列表中的操作进行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排序。

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.要查看如何为批量操作执行对操作进行分组，请在执行后调用Bulk.getOperations()。

Transactions事务

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

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。To use write concern with transactions, see Transactions and Write Concern.要在事务中使用写入关注，请参阅事务和写入关注。