Professional Cloud Architect – Google Cloud Certification Guide

Data consistency

If you are looking for guaranteed strong consistency, then Cloud Spanner is the storage offering for you! This is all down to the fact it is designed for the cloud and, therefore, will negate a lot of the constraints of other storage offerings. In fact, we should note that Cloud Spanner actually provides external consistency, which is a stronger property than strong consistency. This is the strictest consistency property for transaction-processing systems.

When we speak about data consistency with regard to Cloud Spanner, it is wise to raise awareness of the concept of the CAP theorem. This theorem says that a database can only have two out of three of the following properties:

• C: Consistency. This implies a single value ...