Databases

What is a database?

A database is the second highest level in the Objectivity/DB logical storage hierarchy. Each database stores an application’s persistent data in structures called containers, which constitute the third level in the Objectivity/DB logical storage hierarchy. Within a container, persistent data is stored in fundamental units called basic objects.

A database is physically represented by a database file, which contains:

➤ The database’s default container.
➤ Zero or more containers created by applications.
➤ A catalog of the containers belonging to the database.

Database files are typically used to distribute related containers and their basic objects to different physical locations in your network.

How do I create a database?

There are two ways that you can create a database:

1. Run oonewdb with the -db option and the boot file path.
2. Create a database object in an Objectivity/DB application and cluster it to a federated database

For code examples on how to create and use databases in an application, visit our How To's section.

Can I change the properties of a database?

Yes. You can change the following properties of a database:

1. Read-only or read/write.
2. Host and path of the database file.
3. System name or database identifier.
4. Storage-page size.