commitTransaction
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Definition
commitTransaction
Saves the changes made by the operations in the multi-document transaction and ends the transaction.
Tip
In
mongosh
, this command can also be run through theSession.commitTransaction()
andSession.withTransaction()
helper methods.Helper methods are convenient for
mongosh
users, but they may not return the same level of information as database commands. In cases where the convenience is not needed or the additional return fields are required, use the database command.To run the
commitTransaction
, the command must be run against theadmin
database and run within aSession()
.
Compatibility
This command is available in deployments hosted in the following environments:
MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
Note
This command is supported in all MongoDB Atlas clusters. For information on all commands, see Unsupported Commands.
MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB
Syntax
The command has the following syntax:
{ commitTransaction: 1, txnNumber: <long>, writeConcern: <document>, autocommit: false, comment: <any> }
Behavior
Write Concern
When committing the transaction, the session uses the write
concern specified at the transaction start.
See Session.startTransaction()
.
If you commit using the "w: 1"
write
concern, your transaction can be rolled back if there is a
failover..
Atomicity
When a transaction commits, all data changes made in the transaction are saved and visible outside the transaction. That is, a transaction will not commit some of its changes while rolling back others.
Until a transaction commits, the data changes made in the transaction are not visible outside the transaction.
However, when a transaction writes to multiple shards, not all
outside read operations need to wait for the result of the committed
transaction to be visible across the shards. For example, if a
transaction is committed and write 1 is visible on shard A but write
2 is not yet visible on shard B, an outside read at read concern
"local"
can read the results of write 1 without
seeing write 2.