Brief Introduction to Oracle Architecture

Components of Oracle Architecture

Oracle architecture includes a number of basic components we'll cover them in more detail below.

1, Oracle Server: Oracle server contains a variety of file structure, process structure and memory structure, but not all of these structures are used when processing SQL statements. Some structures are used to improve database performance, ensure that the database is recoverable when it encounters software or hardware errors, or perform other tasks required to maintain the database. Oracle servers include an Oracle instance and an Oracle database.

2. Oracle instance: Oracle instance is a combination of background process and memory structure. The data in the database can be accessed only after the instance is started. Each time the instance is started, the system global Area (SGA) is allocated and the Oracle background process is started. The background process performs various functions on behalf of the calling process. They unify the functionality that is handled by multiple Oracle programs that run for each user. Background processes perform input/output (I/O) and monitor other Oracle processes to improve parallelism, making performance and reliability more advantageous.

3, Oracle Database: Oracle database contains operating system files (also known as database files), which provide the actual physical storage of database information. The database file is used to ensure data consistency and to recover when the instance fails.

4. Other key files: non-database files for configuring instances, verifying privileged users, and when a disk fails

Restore the database.

5, user processes and server processes: When executing SQL statements, user processes and server processes are the main processes involved, but other processes can also help the server complete the processing of SQL statements.

6. Other processes: There are many other processes available for other options, such as advanced queuing (advancedqueuing), real-time application clusters (real application clusters), shared servers (sharing server), and

Advanced Replication (Advanced Replication). These processes will be discussed separately in the corresponding courses.