Oracle Database 19c Overview And New Features

Oracle Database 19c Overview And New Features

Agenda

• Oracle Database 19c Multitenant Architecture
• 19 New features and Advantage
• Common and local users in Multitenant Environment
• Startup and stop of database in Multitenant  environment
• Backup in multitenant Environment
• Online migration of an active data file
• Online table partition or sub-partition migration
• Invisible column

 Multiple indexes on the same column

 DDL logging

 Temporary undo in- and- outs

  New backup user privilege

  How to execute SQL statement in RMAN

  Table level recovery in RMAN

  Restricting PGA size

Multitenant Architecture

Every CDB has the following containers:

• Exactly one CDB root container (also called simply the root)
• The CDB root is a collection of schemas, schema objects, and nonschema objects to which all PDBs belong to . The root stores Oracle-supplied metadata and common users. . A common user is a database user known in every container. The root container is named CDB$ROOT.
• Exactly one system container
• The system container includes the root CDB and all PDBs in the CDB. Thus, the system container is the logical container for the CDB itself.
• Zero or more application containers
• An application container consists of exactly one application root, and the PDBs plugged in to this root. Whereas the system container contains the CDB root and all the PDBs within the CDB, an application container includes only the PDBs plugged into the application root. An application root belongs to the CDB root and no other container.
• Zero or more user-created PDBs
• You can define a set of application-specific PDBs as a single component, called an application container. You can then define one or more applications within this container. Each application is a named, versioned set of common metadata and data shared within this application container.

• For example, each customer of a SaaS vendor could have its own application PDB. Each application PDB might have identically defined tables named sales_mlt, with different data in each PDB. The PDBs could share a data-linked common object named countries_olt, which has identical data in each PDB. As an application administrator, you could manage the master application definition so that every new customer gets a PDB with the same objects, and every change to existing schemas (for example, the addition of a new table, or a change in the definition of a table) applies to all PDBs that share the application definition.
• A PDB contains the data and code required for a specific set of features ( For example, a PDB can support a specific application, such as a human resources or sales application. No PDBs exist at creation of the CDB. You add PDBs based on your business requirements.
• A PDB belongs to exactly zero or one application container. If a PDB belongs to an application container, then it is an application PDB. For example, the cust1_pdb and cust2_pdb application PDBs might belong to the saas_sales_ac application container, in which case they belong to no other application containers. An application seed is an optional application PDB that acts as a user-created PDB template, enabling you to create new application PDBs rapidly.
• Exactly one seed PDB
• The seed PDB is a system-supplied template that the CDB can use to create new PDBs. The seed PDB is named PDB$SEED. You cannot add or modify objects in PDB$SEED
• 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.
• The multitenant architecture enables an Oracle database to function as a multitenant container database (CDB) that includes zero, one, or many customer-created Pluggable Databases (PDBs). A PDB is a portable collection of schemas, schema objects, and nonschema objects that appears to an Oracle Net client as a non-CDB. All Oracle databases before Oracle Database 12 were non-CDBs.
• A container is logical collection of data or metadata within the multitenant architecture
• A CDB includes the following components:

        Root: The root, named CDB$ROOT, stores Oracle-supplied metadata and common users. Exactly one         system container. The CDB root is a collection of schemas, schema objects, and nonschema objects to             which all PDBs belong. The root container is named CDB$ROOT.