Bulk Write Operations批量写入操作¶

Overview概述¶

MongoDB provides clients the ability to perform write operations in bulk. MongoDB为客户端提供了批量执行写操作的能力。Bulk write operations affect a single collection. 大容量写入操作影响单个集合。MongoDB allows applications to determine the acceptable level of acknowledgement required for bulk write operations.MongoDB允许应用程序确定批量写入操作所需的可接受确认级别。

The db.collection.bulkWrite() method provides the ability to perform bulk insert, update, and remove operations. db.collection.bulkWrite()方法提供执行大容量插入、更新和删除操作的能力。MongoDB also supports bulk insert through the db.collection.insertMany().MongoDB还支持通过db.collection.insertMany()进行大容量插入。

Ordered vs Unordered Operations有序与无序操作¶

Bulk write operations can be either ordered or unordered.大容量写入操作可以是有序的，也可以是无序的。

With an ordered list of operations, MongoDB executes the operations serially. 通过有序的操作列表，MongoDB以串行方式执行操作。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。See ordered Bulk Write请参阅有序批量写入

With an unordered list of operations, MongoDB can execute the operations in parallel, but this behavior is not guaranteed. 对于无序的操作列表，MongoDB可以并行执行这些操作，但不能保证这种行为。If an error occurs during the processing of one of the write operations, MongoDB will continue to process 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将继续处理列表中的其余写入操作。See Unordered Bulk Write.请参阅无序批量写入。

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.在分片集合上执行操作的有序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。

By default, bulkWrite() performs ordered operations. 默认情况下，bulkWrite()执行有序操作。To specify unordered write operations, set ordered : false in the options document.要指定unordered写入操作，请在选项文档中设置ordered: false。

See Execution of Operations请参阅操作的执行

bulkWrite() MethodsbulkWrite()方法¶

bulkWrite() supports the following write operations:支持以下写入操作：

• insertOne
• updateOne
• updateMany
• replaceOne
• deleteOne
• deleteMany

Each write operation is passed to bulkWrite() as a document in an array.每个写入操作都作为数组中的文档传递给bulkWrite()。

For example, the following performs multiple write operations:例如，以下操作将执行多个写入操作：

The characters collection contains the following documents:characters集合包含以下文档：

{ "_id" : 1, "char" : "Brisbane", "class" : "monk", "lvl" : 4 },
{ "_id" : 2, "char" : "Eldon", "class" : "alchemist", "lvl" : 3 },
{ "_id" : 3, "char" : "Meldane", "class" : "ranger", "lvl" : 3 }

The following bulkWrite() performs multiple operations on the collection:以下bulkWrite()对集合执行多个操作：

try {
   db.characters.bulkWrite(
      [
         { insertOne :
            {
               "document" :
               {
                  "_id" : 4, "char" : "Dithras", "class" : "barbarian", "lvl" : 4
               }
            }
         },
         { insertOne :
            {
               "document" :
               {
                  "_id" : 5, "char" : "Taeln", "class" : "fighter", "lvl" : 3
               }
            }
         },
         { updateOne :
            {
               "filter" : { "char" : "Eldon" },
               "update" : { $set : { "status" : "Critical Injury" } }
            }
         },
         { deleteOne :
            { "filter" : { "char" : "Brisbane" } }
         },
         { replaceOne :
            {
               "filter" : { "char" : "Meldane" },
               "replacement" : { "char" : "Tanys", "class" : "oracle", "lvl" : 4 }
            }
         }
      ]
   );
}
catch (e) {
   print(e);
}

The operation returns the following:该操作返回以下内容：

{
   "acknowledged" : true,
   "deletedCount" : 1,
   "insertedCount" : 2,
   "matchedCount" : 2,
   "upsertedCount" : 0,
   "insertedIds" : {
      "0" : 4,
      "1" : 5
   },
   "upsertedIds" : {

   }
}

For more examples, see bulkWrite() Examples有关更多示例，请参阅bulkWrite()示例

Strategies for Bulk Inserts to a Sharded Collection批量插入到分片集合的策略¶

Large bulk insert operations, including initial data inserts or routine data import, can affect sharded cluster performance. 大批量插入操作（包括初始数据插入或例行数据导入）可能会影响分片集群的性能。For bulk inserts, consider the following strategies:对于批量插入，考虑以下策略：

using namespace mongo;
OID make_an_id() {
  OID x = OID::gen();
  const unsigned char *p = x.getData();
  swap( (unsigned short&) p[0], (unsigned short&) p[10] );
  return x;
}

void foo() {
  // create an object
  BSONObj o = BSON( "_id" << make_an_id() << "x" << 3 << "name" << "jane" );
  // now we may insert o into a sharded collection
}