Configuring Multi-Region Data Stores

Oracle NoSQL Database supports Multi-Region Architecture in which you can create tables in multiple data stores, and still maintain consistent data across these clusters. Each data store in a Multi-Region Oracle NoSQL Database setup is called a Region. A Multi-Region Table or MR Table is a global logical table that is stored and maintained in different regions. MR Tables maintain consistent data in all the regions. That is, any updates made to an MR Table in one region automatically applies to the corresponding MR Table in all the other participating regions. To learn more about Oracle NoSQL Database Multi-Region Architecture and MR Tables, see Multi-Region Architecture in the Concepts Guide.

Replication in a Multi-Region Table:

All writes to the table, including insert, update, and delete would be replicated. All DDL operations (Create Table, Alter Table and Drop Table, Create Index, Alter Index and Drop Index) and operations that change the table metadata like TTL, will not be replicated. For example, the following actions will not be replicated.
  • Index creation in one region
  • Altering the definition of an existing index from one region
  • Dropping the index from one region
  • Changing the schema definition in one region
  • Changing the Table's default Table Time to Live (TTL) in one region

You can configure a Multi-Region Oracle NoSQL Database, and create and manipulate the MR Tables using the Oracle NoSQL Database command-line interface (CLI).The remainder of this chapter is organized into four use cases to demonstrate the different features of the Multi-Region Oracle NoSQL Database and MR Tables. The examples provided show you which commands to use and how. For a complete list of all the commands available in the CLI, see Admin CLI Reference.

Child MR Tables:

You can create child tables in the Multi-Region architecture. That means an existing Multi-Region table can have child tables. You can add a child table to a top-level table that is already a Multi-Region table, and the child table will be automatically Multi-Region enabled . That is an entire table hierarchy is Multi-Region or none of it is. You can drop a child from a top-level table, and the child table will be removed from the hierarchy. The child table will also be removed from the MR Table graph such that it no longer participates in cross region replication.