Transactions in Google Cloud Datastore

Transactions allow you to specify a series of changes to the data store and commit them as one. If any of the individual operations fails, the whole transaction will not be applied. This is extremely useful if you want to maintain counters or have multiple entities that depend on each other's state. During a transaction in Google Cloud Datastore, all entities that are read are locked (other code is prevented from making changes) until the transaction is complete, providing an additional sense of security and preventing data races.

Note

If you were building a bank (it seems crazy, but the guys at Monzo in London are indeed building a bank using Go), you might represent user accounts as an entity called Account. To transfer money from one account to another, you'd need to make sure the money was deducted from account A and deposited into account B as a single transaction. If either fails, people aren't going to be happy (to be fair, if the deduction operation...