The oracle database architecture

Oracle Database

1. Oracle DBA walkthrough Demo Course Presenter – Akash Pramanik

2. Table of contents Topic Slide Number From the Books 3 Duties of Database Administrators 4 Memory architecture 5 Process architecture 6 Instance Startup and Shutdown 7 Tools for Database Administrators 8 About Trainer 9 Do not Copy 2

3. A Relational database management system (RDBMS) is a database management system (DBMS) that follows the relational model introduced by Mr. E. F. Codd. Mr. Edgar Frank "Ted" Codd (19 August 1923 – 18 April 2003) was an English computer scientist who, while working for IBM, invented the relational model for database management, the theoretical basis for relational databases. He made other valuable contributions to computer science, but the relational model, a very influential general theory of data management, remains his most mentioned achievement. Oracle database (Oracle DB) is a relational database management system (RDBMS) from the Oracle Corporation. However Oracle Corporations definition is as follows – “An Oracle database is a collection of data treated as a unit. The purpose of a database is to store and retrieve related information. A database server is the key to solving the problems of information management. In general, a server reliably manages a large amount of data in a multiuser environment so that many users can concurrently access the same data. All this is accomplished while delivering high performance. A database server also prevents unauthorized access and provides efficient solutions for failure recovery .” From the Books 3 Do not Copy

4. Duties of Database Administrators Oracle DBAs are responsible for – Understanding the Oracle Database architecture and how the database works. DBAs can expect to perform the following tasks : Installing , upgrading, and patching Oracle Database software Designing databases, including identifying requirements, creating the logical design (conceptual model), and physical database design Developing and testing a backup and recovery strategy, backing up Oracle databases regularly, and recovering them in case of failures Configuring the network environment to enable clients to connect to databases Starting up and shutting down the database Managing storage for the database, Managing users and security Managing database objects such as tables, indexes, and views Monitoring and tuning database performance Investigating, gathering diagnostic data for, and reporting to Oracle Support Services any critical database errors 4 Do not Copy

5. Memory architecture Oracle Database creates and uses memory structures for purposes such as memory for program code, data shared among users, and private data areas for each connected user. The following memory structures are associated with an instance: System Global Area (SGA) – The SGA is a group of shared memory structures that contain data and control information for one database instance. Examples of SGA components include cached data blocks and shared SQL areas. Program Global Areas (PGA) – A PGA is a memory region that contain data and control information for a server or background process. Access to the PGA is exclusive to the process. Each server process and background process has its own PGA. Software code area – Software code areas are portions of memory that store code that is being run or can be run. Oracle Database code is stored in a software area that is typically more exclusive and protected than the location of user programs. Software areas are usually static in size, changing only when software is updated or reinstalled. The required size of these areas varies by operating system. User Global Area – The UGA is  session memory , which is memory allocated for session variables, such as logon information, and other information required by a database session. 5 Do not Copy

6. Process architecture A process is a mechanism in an operating system that can run a series of steps. Some operating systems use the terms job, task, or thread. For the purpose of this discussion, a thread is equivalent to a process. An Oracle database instance has the following types of processes: Client processes – These processes are created and maintained to run the software code of an application program or an Oracle tool. Most environments have separate computers for client processes. Background processes – These processes consolidate functions that would otherwise be handled by multiple Oracle Database programs running for each client process. Background processes asynchronously perform I/O and monitor other Oracle Database processes to provide increased parallelism for better performance and reliability. Server processes – These processes communicate with client processes and interact with Oracle Database to fulfill requests. 6 Do not Copy

7. Instance Startup and Shutdown Oracle database uses its memory structures and processes to manage and access the database. An instance is a set of memory structures that manage database files. The instance consists of a shared memory area, called the system global area (SGA), and a set of background processes. An instance can exist independently of database files. Overview of Database and Instance Startup Overview of Database and Instance Shutdown 7 Do not Copy

8. Tools for Database Administrators Oracle Enterprise Manager SQL*Plus Tools for Database Installation and Configuration Tools for Oracle Net Configuration and Administration Tools for Data Movement and Analysis 8 Do not Copy

9. About Trainer 9 Do not Copy Mr Akash Pramanik Oracle Database Administrator by profession and a freelance Trainer/Teacher by passion. With exceptional presentation and training program design abilities I have provided training to employees, students, interns, fresher trainees using classroom, conferences and online facilities. I am specialized in Oracle Database (12c, 11g, 10g), Oracle Apps (11i, R12), Oracle Business Intelligence, Oracle FMW products, Oracle Data Integrator, Oracle Golden Gate, Exadata, PL/SQL, MongoDB , Hadoop , Teradata , Linux, Unix, etc. I am also proficient in training in non-technical subjects like Software Development Life Cycle, Information Life Cycle Management, Project Planning and Management, Communication and Personality Development, US accent Training, etc.

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