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db.collection.initializeOrderedBulkOp()

Definition

db.collection.initializeOrderedBulkOp()

Initializes and returns a new Bulk() operations builder for a collection. The builder constructs an ordered list of write operations that MongoDB executes in bulk.

返回:new Bulk() operations builder object.

Behavior

Order of Operation

With an ordered operations list, MongoDB executes the write operations in the list serially.

Execution of 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.

Error Handling

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.

Examples

The following initializes a Bulk() operations builder on the users collection, adds a series of write operations, and executes the operations:

var bulk = db.users.initializeOrderedBulkOp();
bulk.insert( { user: "abc123", status: "A", points: 0 } );
bulk.insert( { user: "ijk123", status: "A", points: 0 } );
bulk.insert( { user: "mop123", status: "P", points: 0 } );
bulk.find( { status: "D" } ).remove();
bulk.find( { status: "P" } ).update( { $set: { comment: "Pending" } } );
bulk.execute();