Oracle Database Architecture Explained
Hello again! In my last article I mentioned how you can use a theme reference site to guide building in Oracle Apex, turns out you can also install in your workspace. It is part of the sample apps that come built with an Apex installation. You can access and install it in the Gallery section of the Apex homepage.
As someone facinated by Oracle databases, I think its fair I document knowledge on it explaining concepts the way I understand them. We will in an overview look at what the architecture of Oracle databases look like.
An Oracle database is a collection of data stored in files on an operating system. These files contain both the physical data and metadata for users and the system itself. Additionally, there are files for configuring the database system and managing data recovery and consistency.
The database is organized into logical groupings called schemas, which hold database objects for users and applications. These objects are persistently stored and are available even when the database is not running.
When an Oracle database is started, it creates a set of memory structures and processes known as the Oracle instance. The memory structures store data in various pools and formats for different purposes, while the processes, also called background processes, handle server-side operations like accessing, modifying, and managing the data.
Apart from the background processes, there are foreground processes that work on behalf of application and database users. These processes handle tasks such as parsing, executing SQL statements and returning results to client programs.
The Oracle Database architecture also includes the networking and connectivity component. This involves a software layer responsible for managing communication and ensuring security between the server, other servers, and clients. Oracle Net Services, a suite of networking components, provides connectivity solutions in distributed computing environments, enabling communication between application and database instances.
Regarding database file storage, there are three common approaches.
- The first approach is using operating system file systems, which are built on top of a logical volume managed by a software package called a Logical Volume Manager (LVM). The LVM combines sections of multiple physical disks into a single address space.
- The second approach is clustered file systems, which allow multiple computers to share file storage while maintaining consistent space allocation and file content.
- The third approach is Automatic Storage Management (ASM), a specialized volume manager designed for high-performance database file systems and disk management. ASM eliminates the need for direct management of Oracle Database files and groups disks in storage systems into one or more disk groups.
Understanding these basic components of the database architecture lays the foundation for using the Oracle Database effectively. It is also essential for anyone venturing into the realm of database management and administration.
Ultimately, with this solid foundation, coupled with continuous learning and hands-on experience, you can harness the power of this robust system to build scalable applications, ensure data integrity, and drive innovation.
