Oracle Architecture Explained

The architecture of Oracle refers to the components and relationships within the Oracle database system. It mainly consists of the following components:

1. Example: An instance is a collection of processes running in memory in an Oracle database system, which includes multiple background processes and memory structures responsible for managing the database’s memory and processes. The instance’s tasks include handling user connection requests, parsing SQL statements, executing SQL statements, and managing the database buffer cache.
2. Database: A database is a storage unit composed of physical files such as data files, control files, and log files. It contains database objects such as tables, indexes, views, and stored procedures.
3. Database files: They are physical files used to store data and metadata in a database, including data files, control files, and log files.
4. Data Buffer: A section of memory within an instance used to store recently accessed data blocks, reducing the frequency of disk I/O operations.
5. Data Dictionary: The data dictionary is a system table in Oracle database that stores metadata information, used to describe the structure and objects of the database.
6. Processes: Oracle database system consists of multiple processes, including foreground processes, background processes, monitoring processes, etc., used to manage database connections, transactions, buffer pools, etc.

The above is the basic architecture of the Oracle database system, different versions of Oracle databases may have some differences, but overall they follow this structure.