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- Bulk.execute()
Bulk.execute()¶
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Tip
Starting in version 3.2, MongoDB also provides the
db.collection.bulkWrite()
method for performing bulk
write operations.
Description¶
-
Bulk.
execute
()¶ New in version 2.6.
Executes the list of operations built by the
Bulk()
operations builder.Bulk.execute()
accepts the following parameter:Parameter Type Description writeConcern
document Optional. Write concern document for the bulk operation as a whole. Omit to use default. For a standalone
mongod
server, the write concern defaults to{ w: 1 }
. With a replica set, the default write concern is{ w: 1 }
unless modified as part of the replica set configuration.See Override Default Write Concern for an example.
Returns: A BulkWriteResult
object that contains the status of the operation.After execution, you cannot re-execute the
Bulk()
object without reinitializing. Seedb.collection.initializeUnorderedBulkOp()
anddb.collection.initializeOrderedBulkOp()
.
Behavior¶
Ordered Operations¶
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.
Each group of operations can have at most 1000 operations
. If a group exceeds this limit
, MongoDB will divide the group into
smaller groups of 1000 or less. For example, if the bulk operations list
consists of 2000 insert operations, MongoDB creates 2 groups, each with
1000 operations.
The sizes and grouping mechanics are internal performance details and are subject to change in future versions.
To see how the operations are grouped for a 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¶
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.
Each group of operations can have at most 1000 operations
. If a group exceeds this limit
, MongoDB will divide the group into
smaller groups of 1000 or less. For example, if the bulk operations list
consists of 2000 insert operations, MongoDB creates 2 groups, each with
1000 operations.
The sizes and grouping mechanics are internal performance details and are subject to change in future versions.
To see how the operations are grouped for a bulk operation execution,
call Bulk.getOperations()
after the execution.
Examples¶
Execute Bulk Operations¶
The following initializes a Bulk()
operations builder on the
items
collection, adds a series of insert operations, and executes
the operations:
var bulk = db.items.initializeUnorderedBulkOp();
bulk.insert( { item: "abc123", status: "A", defaultQty: 500, points: 5 } );
bulk.insert( { item: "ijk123", status: "A", defaultQty: 100, points: 10 } );
bulk.execute( );
The operation returns the following BulkWriteResult()
object:
BulkWriteResult({
"writeErrors" : [ ],
"writeConcernErrors" : [ ],
"nInserted" : 2,
"nUpserted" : 0,
"nMatched" : 0,
"nModified" : 0,
"nRemoved" : 0,
"upserted" : [ ]
})
For details on the return object, see BulkWriteResult()
. For
details on the batches executed, see Bulk.getOperations()
.
Override Default Write Concern¶
The following operation to a replica set specifies a write
concern of "w: majority"
with a
wtimeout
of 5000 milliseconds such that the method returns after
the writes propagate to a majority of the voting replica set members or
the method times out after 5 seconds.
Changed in version 3.0: In previous versions, majority
referred to the majority of all
members of the replica set instead of the majority of the voting
members.
var bulk = db.items.initializeUnorderedBulkOp();
bulk.insert( { item: "efg123", status: "A", defaultQty: 100, points: 0 } );
bulk.insert( { item: "xyz123", status: "A", defaultQty: 100, points: 0 } );
bulk.execute( { w: "majority", wtimeout: 5000 } );
The operation returns the following BulkWriteResult()
object:
BulkWriteResult({
"writeErrors" : [ ],
"writeConcernErrors" : [ ],
"nInserted" : 2,
"nUpserted" : 0,
"nMatched" : 0,
"nModified" : 0,
"nRemoved" : 0,
"upserted" : [ ]
})
See
Bulk()
for a listing of methods available for bulk
operations.