db.collection.bulkWrite()
Definition
mongo
Shell Method
This page documents the mongo
shell method, and doesnot refer to the MongoDB Node.js driver (or any other driver)method. For corresponding MongoDB driver API, refer to your specificMongoDB driver documentation instead.
New in version 3.2.
Performs multiple write operations with controls for order ofexecution.
db.collection.bulkWrite()
has the following syntax:
- db.collection.bulkWrite(
- [ <operation 1>, <operation 2>, ... ],
- {
- writeConcern : <document>,
- ordered : <boolean>
- }
- )
ParameterTypeDescriptionoperations
arrayAn array of bulkWrite()
writeoperations.
Valid operations are:
See Write Operations for usage of each operation.writeConcern
documentOptional. A document expressing the write concern. Omit to use the default write concern.
Do not explicitly set the write concern for the operation if run ina transaction. To use write concern with transactions, seeTransactions and Write Concern.ordered
booleanOptional. A boolean specifying whether the mongod
instance should performan ordered or unordered operation execution. Defaults to true
.
Returns:
- A boolean
acknowledged
astrue
if the operation ran withwrite concern orfalse
if write concern was disabled. - A count for each write operation.
- An array containing an
_id
for each successfully inserted orupserted documents.
Behavior
bulkWrite()
takes an array of write operations andexecutes each of them. By default operations are executed in order.See Execution of Operations for controllingthe order of write operation execution.
Write Operations
insertOne
Inserts a single document into the collection.
- db.collection.bulkWrite( [
- { insertOne : { "document" : <document> } }
- ] )
See db.collection.insertOne()
.
updateOne and updateMany
- updateOne
- updateMany
updateOne
updates a single document in the collection that matches thefilter. If multiple documents match, updateOne
will update the _first_matching document only.
- db.collection.bulkWrite( [
- { updateOne :
- {
- "filter": <document>,
- "update": <document or pipeline>, // Changed in 4.2
- "upsert": <boolean>,
- "collation": <document>, // Available starting in 3.4
- "arrayFilters": [ <filterdocument1>, ... ], // Available starting in 3.6
- "hint": <document|string> // Available starting in 4.2.1
- }
- }
- ] )
updateMany
updates all documents in the collectionthat match the filter.
- db.collection.bulkWrite( [
- { updateMany :
- {
- "filter" : <document>,
- "update" : <document or pipeline>, // Changed in MongoDB 4.2
- "upsert" : <boolean>,
- "collation": <document>, // Available starting in 3.4
- "arrayFilters": [ <filterdocument1>, ... ], // Available starting in 3.6
- "hint": <document|string> // Available starting in 4.2.1
- }
- }
- ] )
Field | Notes |
---|---|
filter | The selection criteria for the update. The same queryselectors as in thedb.collection.find() method are available. |
update | The update operation to perform. Can specify either:- A document that only contains update operator expressions.- An aggregation pipeline [<stage1>, <stage2>, … ] that specifies the modifications toperform. |
upsert | Optional. A boolean to indicate whether to perform an upsert.By default, upsert is false . |
arrayFilters | Optional. An array of filter documents that determine whicharray elements to modify for an update operation on an arrayfield. |
collation | Optional. Specifies the collation to use forthe operation. |
hint | Optional. The index to use to support theupdate filter . If you specify an index that does not exist,the operation errors.New in version 4.2.1. |
For details, see db.collection.updateOne()
anddb.collection.updateMany()
.
replaceOne
replaceOne
replaces a single document in the collection that matches thefilter. If multiple documents match, replaceOne
will replace the _first_matching document only.
- db.collection.bulkWrite([
- { replaceOne :
- {
- "filter" : <document>,
- "replacement" : <document>,
- "upsert" : <boolean>,
- "collation": <document>, // Available starting in 3.4
- "hint": <document|string> // Available starting in 4.2.1
- }
- }
- ] )
Field | Notes |
---|---|
filter | The selection criteria for the replacement operation. The samequery selectors as in thedb.collection.find() method are available. |
replacement | The replacement document. The document cannot containupdate operators. |
upsert | Optional. A boolean to indicate whether to perform an upsert. Bydefault, upsert is false . |
collation | Optional. Specifies the collation to use forthe operation. |
hint | Optional. The index to use to support theupdate filter . If you specify an index that does not exist,the operation errors.New in version 4.2.1. |
For details, see to db.collection.replaceOne()
.
deleteOne and deleteMany
- deleteOne
- deleteMany
deleteOne
deletes a single document in the collection that match thefilter. If multiple documents match, deleteOne
will delete the _first_matching document only.
- db.collection.bulkWrite([
- { deleteOne : {
- "filter" : <document>,
- "collation" : <document> // Available starting in 3.4
- } }
- ] )
deleteMany
deletes all documents in the collectionthat match the filter.
- db.collection.bulkWrite([
- { deleteMany: {
- "filter" : <document>,
- "collation" : <document> // Available starting in 3.4
- } }
- ] )
Field | Notes |
---|---|
filter | The selection criteria for the delete operation. The samequery selectors as in thedb.collection.find() method are available. |
collation | Optional. Specifies the collation to use forthe operation. |
For details, see db.collection.deleteOne()
anddb.collection.deleteMany()
.
_id Field
If the document does not specify an _id field, then mongod
adds the _id
field and assign a uniqueObjectId
for the document before inserting or upserting it.Most drivers create an ObjectId and insert the _id
field, but themongod
will create and populate the _id
if the driver orapplication does not.
If the document contains an _id
field, the _id
value must beunique within the collection to avoid duplicate key error.
Update or replace operations cannot specify an _id
value that differsfrom the original document.
Execution of Operations
The ordered
parameter specifies whetherbulkWrite()
will execute operations in order or not.By default, operations are executed in order.
The following code represents a bulkWrite()
withfive operations.
- db.collection.bulkWrite(
- [
- { insertOne : <document> },
- { updateOne : <document> },
- { updateMany : <document> },
- { replaceOne : <document> },
- { deleteOne : <document> },
- { deleteMany : <document> }
- ]
- )
In the default ordered : true
state, each operation willbe executed in order, from the first operation insertOne
to the last operation deleteMany
.
If ordered
is set to false, operations may be reordered bymongod
to increase performance.Applications should not depend on order of operation execution.
The following code represents an unorderedbulkWrite()
with six operations:
- db.collection.bulkWrite(
- [
- { insertOne : <document> },
- { updateOne : <document> },
- { updateMany : <document> },
- { replaceOne : <document> },
- { deleteOne : <document> },
- { deleteMany : <document> }
- ],
- { ordered : false }
- )
With ordered : false
, the results of the operation may vary. For example,the deleteOne
or deleteMany
may remove more or fewer documentsdepending on whether the run before or after the insertOne
, updateOne
,updateMany
, or replaceOne
operations.
The number of operations in each group cannot exceed the value ofthe maxWriteBatchSize
ofthe database. As of MongoDB 3.6, this value is 100,000
.This value is shown in the isMaster.maxWriteBatchSize
field.
This limit prevents issues with oversized error messages. If a groupexceeds this limit
,the client driver divides the group into smaller groups with countsless than or equal to the value of the limit. For example, with themaxWriteBatchSize
value of 100,000
, if the queue consists of200,000
operations, the driver creates 2 groups, each with100,000
operations.
Note
The driver only divides the group into smaller groups when usingthe high-level API. If usingdb.runCommand() directly(for example, when writing a driver), MongoDB throws an error whenattempting to execute a write batch which exceeds the limit.
Starting in MongoDB 3.6, once the error report for a single batch growstoo large, MongoDB truncates all remaining error messages to the emptystring. Currently, begins once there are at least 2 error messages withtotal size greater than 1MB
.
The sizes and grouping mechanics are internal performance details andare subject to change in future versions.
Executing an ordered
list of operations on asharded collection will generally be slower than executing anunordered
listsince with an ordered list, each operation must wait for the previousoperation to finish.
Capped Collections
bulkWrite()
write operations have restrictions whenused on a capped collection.
updateOne
and updateMany
throw a WriteError
if theupdate
criteria increases the size of the document being modified.
replaceOne
throws a WriteError
if thereplacement
document has a larger size than the originaldocument.
deleteOne
and deleteMany
throw a WriteError
if used on acapped collection.
Transactions
db.collection.bulkWrite()
can be used inside multi-document transactions.
If run inside a transaction, the collection must already exist forinsert and upsert: true
operations.
Do not explicitly set the write concern for the operation if run ina transaction. To use write concern with transactions, seeTransactions and Write Concern.
Important
In most cases, multi-document transaction incurs a greaterperformance cost over single document writes, and theavailability of multi-document transactions should not be areplacement for effective schema design. For many scenarios, thedenormalized data model (embedded documents and arrays) will continue to be optimal for yourdata and use cases. That is, for many scenarios, modeling your dataappropriately will minimize the need for multi-documenttransactions.
For additional transactions usage considerations(such as runtime limit and oplog size limit), see alsoProduction Considerations.
For error handling inside a transaction, see Error Handling inside Transactions.
Error Handling
db.collection.bulkWrite()
throws a BulkWriteError
exception on errors (unless the operation is part of a transaction onMongoDB 4.0). See Error Handling inside Transactions.
Excluding Write Concern errors, ordered operationsstop after an error, while unordered operations continue to process anyremaining write operations in the queue, unless when run inside atransaction. See Error Handling inside Transactions.
Write concern errors are displayed in the writeConcernErrors
field, whileall other errors are displayed in the writeErrors
field. If an error isencountered, the number of successful write operations are displayed insteadof the inserted _id
values. Ordered operations display the single errorencountered while unordered operations display each error in an array.
Transactions
db.collection.bulkWrite()
can be used inside multi-document transactions.
If run inside a transaction, the collection must already exist forinsert and upsert: true
operations.
Do not explicitly set the write concern for the operation if run ina transaction. To use write concern with transactions, seeTransactions and Write Concern.
Important
In most cases, multi-document transaction incurs a greaterperformance cost over single document writes, and theavailability of multi-document transactions should not be areplacement for effective schema design. For many scenarios, thedenormalized data model (embedded documents and arrays) will continue to be optimal for yourdata and use cases. That is, for many scenarios, modeling your dataappropriately will minimize the need for multi-documenttransactions.
For additional transactions usage considerations(such as runtime limit and oplog size limit), see alsoProduction Considerations.
Error Handling inside Transactions
Starting in MongoDB 4.2, if a db.collection.bulkWrite()
operation encounters an error inside a transaction, the method throws a BulkWriteException (same as outside a transaction).
In 4.0, if the bulkWrite
operation encounters an error inside atransaction, the error thrown is not wrapped as aBulkWriteException
.
Inside a transaction, the first error in a bulk write causes theentire bulk write to fail and aborts the transaction, even if thebulk write is unordered.
Examples
Bulk Write Operations
The characters
collection in the guidebook
database contains the following documents:
- { "_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 multipleoperations on the collection:
- 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:
- {
- "acknowledged" : true,
- "deletedCount" : 1,
- "insertedCount" : 2,
- "matchedCount" : 2,
- "upsertedCount" : 0,
- "insertedIds" : {
- "0" : 4,
- "1" : 5
- },
- "upsertedIds" : {
- }
- }
If the collection had contained a document with "_id" : 5"
before executing the bulk write, then when the bulk write is executed,the following duplicate key exception would be thrown for the second insertOne:
- BulkWriteError({
- "writeErrors" : [
- {
- "index" : 1,
- "code" : 11000,
- "errmsg" : "E11000 duplicate key error collection: guidebook.characters index: _id_ dup key: { _id: 5.0 }",
- "op" : {
- "_id" : 5,
- "char" : "Taeln",
- "class" : "fighter",
- "lvl" : 3
- }
- }
- ],
- "writeConcernErrors" : [ ],
- "nInserted" : 1,
- "nUpserted" : 0,
- "nMatched" : 0,
- "nModified" : 0,
- "nRemoved" : 0,
- "upserted" : [ ]
- })
Since ordered
is true by default, only the first operation completessuccessfully. The rest are not executed. Running thebulkWrite()
with ordered : false
would allow theremaining operations to complete despite the error.
Unordered Bulk Write
The characters
collection in the guidebook
database contains the following documents:
- { "_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 multipleunordered
operations on the characters
collection. Note that one ofthe insertOne
stages has a duplicate _id
value:
- try {
- db.characters.bulkWrite([
- { insertOne: { "document": { "_id": 4, "char": "Dithras", "class": "barbarian", "lvl": 4 } } },
- { insertOne: { "document": { "_id": 4, "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 }
- } }
- ], { ordered : false } );
- } catch (e) {
- print(e);
- }
The operation returns the following:
- BulkWriteError({
- "writeErrors" : [
- {
- "index" : 1,
- "code" : 11000,
- "errmsg" : "E11000 duplicate key error collection: guidebook.characters index: _id_ dup key: { _id: 4.0 }",
- "op" : {
- "_id" : 4,
- "char" : "Taeln",
- "class" : "fighter",
- "lvl" : 3
- }
- }
- ],
- "writeConcernErrors" : [ ],
- "nInserted" : 1,
- "nUpserted" : 0,
- "nMatched" : 2,
- "nModified" : 2,
- "nRemoved" : 1,
- "upserted" : [ ]
- })
Since this was an unordered
operation, the writes remaining in the queuewere processed despite the exception.
Bulk Write with Write Concern
The enemies
collection contains the following documents:
- { "_id" : 1, "char" : "goblin", "rating" : 1, "encounter" : 0.24 },
- { "_id" : 2, "char" : "hobgoblin", "rating" : 1.5, "encounter" : 0.30 },
- { "_id" : 3, "char" : "ogre", "rating" : 3, "encounter" : 0.2 },
- { "_id" : 4, "char" : "ogre berserker" , "rating" : 3.5, "encounter" : 0.12}
The following bulkWrite()
performs multipleoperations on the collection using a write concern value of"majority"
and timeout value of 100 milliseconds:
- try {
- db.enemies.bulkWrite(
- [
- { updateMany :
- {
- "filter" : { "rating" : { $gte : 3} },
- "update" : { $inc : { "encounter" : 0.1 } }
- },
- },
- { updateMany :
- {
- "filter" : { "rating" : { $lt : 2} },
- "update" : { $inc : { "encounter" : -0.25 } }
- },
- },
- { deleteMany : { "filter" : { "encounter": { $lt : 0 } } } },
- { insertOne :
- {
- "document" :
- {
- "_id" :5, "char" : "ogrekin" , "rating" : 2, "encounter" : 0.31
- }
- }
- }
- ],
- { writeConcern : { w : "majority", wtimeout : 100 } }
- );
- } catch (e) {
- print(e);
- }
If the total time required for all required nodes in the replica set toacknowledge the write operation is greater than wtimeout
,the following writeConcernError
is displayed when the wtimeout
periodhas passed.
- BulkWriteError({
- "writeErrors" : [ ],
- "writeConcernErrors" : [
- {
- "code" : 64,
- "codeName" : "WriteConcernFailed",
- "errmsg" : "waiting for replication timed out",
- "errInfo" : {
- "wtimeout" : true
- }
- },
- {
- "code" : 64,
- "codeName" : "WriteConcernFailed",
- "errmsg" : "waiting for replication timed out",
- "errInfo" : {
- "wtimeout" : true
- }
- },
- {
- "code" : 64,
- "codeName" : "WriteConcernFailed",
- "errmsg" : "waiting for replication timed out",
- "errInfo" : {
- "wtimeout" : true
- }
- }
- ],
- "nInserted" : 1,
- "nUpserted" : 0,
- "nMatched" : 4,
- "nModified" : 4,
- "nRemoved" : 1,
- "upserted" : [ ]
- })
The result set shows the operations executed sincewriteConcernErrors
errors are not an indicator that any writeoperations failed.