Oracle Database 12c – All about Multitenant Architecture
Why Multitenant Architecture introduced with 12c?
Many Oracle customers have large numbers of applications built on Oracle RDBMS. They do not use a significant percentage of the hardware on which they are deployed.Customers have instance and storage overhead preventing large numbers of databases from being placed on the same physical and storage server. They are not generally complex to require 100% of the attention of a full time administrator And they do require significant time to patch or upgrade all applications.
Multitenant Architecture is the answer to all these problems. It basically provides a cloud of Oracle database.
3) There are two types of containers in Multitenant Architecture–The root container:
- The first container created at CDB creation
- Oracle system-supplied common objects and metadata
- Oracle system-supplied common users and roles
–Pluggable database containers (PDBs):
- A container for an application:
–Tablespaces (permanent and temporary)
–Schemas / objects / privileges
–Created / cloned / unplugged / plugged
- Particular seed PDB:
–PDB$SEED provides fast provisioning of a new PDB
4) There is a Limit of 253 PDBs in a CDB including the seed
5) There is a Limit of 1024 services in a CDB
6) Every PDB has its own set of SYSTEM/SYSAUX/TEMP tablespaces, and also includes the Sample User data such as SCOTT etc..
7) ENABLE_PLUGGABE_DATABASE initialization parameter specifies If a particular Database is CDB or Non-CDB