Introduction to Oracle Database 12c
Key Concepts
- Oracle Database Architecture
- Multitenant Architecture
- Container and Pluggable Databases
- Oracle Database 12c Features
Oracle Database Architecture
Oracle Database 12c is built on a robust architecture that includes various components such as the Instance, Database, and Storage. The Instance consists of the memory structures (SGA - System Global Area) and background processes (PMON, SMON, etc.). The Database is the collection of physical files like datafiles, control files, and redo logs. Storage refers to the physical media where these files are stored.
Multitenant Architecture
Oracle Database 12c introduces a multitenant architecture that allows a single container database (CDB) to host multiple pluggable databases (PDBs). This architecture is akin to a large container ship (CDB) carrying multiple smaller containers (PDBs). Each PDB is isolated and can be managed independently, yet they share common resources from the CDB.
Container and Pluggable Databases
A Container Database (CDB) is the main database that holds all the common metadata and system resources. It can contain one or more Pluggable Databases (PDBs), which are self-contained databases that can be plugged into or unplugged from the CDB. Think of the CDB as a motherboard in a computer, and the PDBs as individual USB drives that can be plugged in and out as needed.
Oracle Database 12c Features
Oracle Database 12c comes with several new features designed to enhance performance, scalability, and manageability. Some of these features include:
- In-Memory Column Store: Accelerates query performance by storing data in memory in a columnar format.
- Adaptive Query Optimization: Dynamically adjusts query execution plans based on runtime statistics.
- Automatic Data Optimization: Automatically manages data placement and compression based on policies.
- Data Redaction: Provides real-time data masking to protect sensitive information.
Understanding these foundational concepts is crucial for anyone aspiring to become an Oracle Database 12c Administrator. By grasping the architecture and features of Oracle Database 12c, you will be well-equipped to manage and optimize database environments effectively.