Thursday, June 5, 2014

1z0-060 Upgrade to Oracle Database 12c - Explain root and multitenant architecture

Extracted from: http://docs.oracle.com/cd/E16655_01/server.121/e17636/cdb_intro.htm#ADMIN14145

A CDB includes the following components:

  • Root

    The root, named CDB$ROOT, stores Oracle-supplied metadata and common users. An example of metadata is the source code for Oracle-supplied PL/SQL packages. A common user is a database user known in every container. A CDB has exactly one root.

  • Seed

    The seed, named PDB$SEED, is a template that you can use to create new PDBs. You cannot add objects to or modify objects in the seed. A CDB has exactly one seed.

  • PDBs

    A PDB appears to users and applications as if it were a non-CDB. For example, a PDB can contain the data and code required to support a specific application. A PDB is fully backward compatible with Oracle Database releases before Oracle Database 12c.

Each of these components is called a container. Therefore, the root is a container, the seed is a container, and each PDB is a container. Each container has a unique container ID and name within a CDB. Figure 36-1 shows a CDB with several PDBs.

Description of Figure 36-1 follows

You can easily plug a PDB into a CDB and unplug a PDB from a CDB. When you plug in a PDB, you associate the PDB with a CDB. When you unplug a PDB, you disassociate the PDB from a CDB. An unplugged PDB consists of an XML file that describes the PDB and the PDB's files (such as the data files and wallet file).

You can unplug a PDB from one CDB and plug it into a different CDB without altering your schemas or applications. A PDB can be plugged into only one CDB at a time.

Each PDB has a globally unique identifier (GUID). The PDB GUID is primarily used to generate names for directories that store the PDB's files, including both Oracle Managed Files directories and non-Oracle Managed Files directories.

image

5 comments:

  1. Where do you come up with this? Just saying you are very imaginative. You should ask your readers for new topics. iphone mockup

    ReplyDelete
  2. Really instructive and superb structure of articles, now that’s user friendly (:. iphone photoshop

    ReplyDelete
  3. Loving the information on this site, you have done outstanding job on the content . device mockup

    ReplyDelete
  4. I think this is one of the most significant information for me. And i’m glad reading your article. But should remark on some general things, The web site style is perfect, the articles is really great : D. Good job, cheers anti parasite herbsanti parasitic foods

    ReplyDelete
  5. While some people fall victim to parasitic infections more than others, almost all parasites are dangerous herbal colon cleansing

    ReplyDelete