Oracle Database: what it is and how it works

Oracle Database is a relational database management system (RDBMS) from the American software and hardware manufacturer Oracle. Being database software, Oracle Database optimizes the management and security of data sets by creating structured database schemas accessible only to authorized administrators.

Oracle Database is a market leader along with SAP HANA, Microsoft SQL Server, and IBM Db2 in the field of relational database management systems (RDBMS for short). According to DB-Engines Ranking, Oracle ranks first among the 380 most popular database systems, immediately followed by MySQL and Microsoft SQL Server. Although Oracle, founded in 1977 by Lawrence J. Ellison, now offers a broad portfolio of products and services, Oracle Database remains the flagship of the American manufacturer. The first version came on the market in 1979. Currently, the long-term version 19c and the Innovation Release 21c are available (as of October 2021).

In a nutshell, Oracle Database forms the core of companies’ IT environments. Databases can be differentiated into various hierarchical, network, object, or document-oriented models, depending on the structuring pattern. Oracle uses a relational database model for Oracle Database, which makes it possible to store and display company and customer data as organized data sets. Data sets are structured into columns, tables, and rows, and data points are related using attributes. Oracle Database is successful due to its intuitive and efficient organization and presentation of data sets. In addition, companies can decide whether to use Oracle Database in local on-premises or cloud environments.

Oracle Database, like most RDBMS, uses the standardized programming language SQL (Structured Query Language) to create database structures, manage records, perform actions, or retrieve contained data. Oracle’s own programming language PL/SQL, in turn, is closely related to SQL and lets you add Oracle programming extensions to SQL. To structure the databases, Oracle uses row and column tables in which data points are linked via attributes. This makes cross-table access efficient and time effective.

The architecture of Oracle database systems consists of a database for storing database files, one or more database instances for data management, and one or more listener processes that connect database clients to database instances. Here, logical and physical data structures are separated into Oracle databases. These include physical and logical storage structures:

1. Physical storage structures: Data files, control files (with database metadata), and red-log files (for documenting changes).
2. Logical storage structures: Data blocks and tables, extents (for grouping logical data blocks), segments (extent records) and tablespaces (logical segment containers).

The clear structure of Oracle databases ensures that data is reliably managed with maximum security measures thanks to data and network encryption, strict authentication, authorization, and authorization analyses. In addition, Oracle supports Java and retrieves Java programming with PL/SQL.

Oracle provides various developer and management tools for the development and extension of Oracle databases:

• SQL*Plus: Available on all computer systems that use the Oracle client or server software. As a command line tool for database administration, it allows command entries, data queries, and changes or deletions of database files. SQL knowledge is mandatory for SQL*Plus.
• Oracle SQL Developer: A free Java program with graphical user interface that creates or edits database projects, manages SQL statements/scripts, performs database analyses, or generates or debugs PL/SQL procedures.
• Oracle Data Modeler: A free tool aimed primarily at database designers. The Modeler can be used to design logical database models or entity-relationship models. The tool’s strengths include its intuitive operation (drag & drop), the mapping of complex database structures, and the export of database structures to the Oracle SQL Developer Tool.
• Oracle Enterprise Manager Database Control: A web-based management tool for Oracle databases that provides a graphical user interface.
• Oracle Enterprise Manager Grid Control: A flexible administration tool for Oracle environments that is web-based and provides a graphical user interface. It can be used for multiple databases, clusters, as well as standby systems.
• Oracle JDeveloper: An Oracle developer tool whose integrated development environment with Oracle and Java helps in developing database applications.

Currently, Oracle Database products can be divided into four main Oracle Editions, which are suitable for different areas of application depending on the size of the company.

The Oracle Express Edition is a free Oracle Database, which is suitable for every client and provides a free database (e.g. for training or small applications). The Express Edition supports PHP, Java, XML, and .NET. Since it’s a free edition, the memory is limited to 4 GB and the RAM to 1 GB. In addition, only one CPU is available.

Large medium-sized companies tend to choose the Oracle Standard Edition. Its advantages include intuitive installation and configuration, automated management functions, an efficient and clear administration of large data sets, as well as a high compatibility with all common data types and applications.

Oracle’s Enterprise Edition is the deluxe version of Oracle Database and also reserves a top price among RDBMS. Since the Enterprise Edition hardly sets limits in terms of storage, extension, and data volume management, it’s mainly suitable for large enterprises that work with enormous volumes of data. Other advantages include reliable security features against data loss, power failures, and software errors.

The advantages and disadvantages of Oracle depend primarily on user requirements and needs as well as costs, technical competencies, and programming skills. A major advantage of Oracle Database is the optional Database-as-a-Service model. This enables relational databases to be stored and managed in the Oracle Cloud. This ensures optimal use of CPU, hardware and storage capacities, as well as the outsourcing of administrative database management tasks. The highest security standards also ensure the greatest possible protection against data loss, cyber attacks, and security breaches.

Some of the benefits of Oracle Database include:

• High compatibility with all platforms and applications
• Support from all major software and hardware vendors
• Different editions from free to enterprise level
• Widely used in the enterprise IT sector
• Optional use of Oracle Cloud Databases for outsourcing and automation of database management
• Most popular relational database management system
• Large developer community and high-quality Oracle support
• Robust security and privacy features (e.g., strong authentication and authorization of access, encryption of data and networks)

The advantages of Oracle databases outweigh the disadvantages, but you should also be aware of its weaknesses.

• Extensive SQL knowledge and administrative experience in database management are a prerequisite for the local on-premises version of Oracle
• Oracle licenses are expensive (Standard Edition approx. 17,000 USD, Enterprise Edition approx. 40,000 USD)
• High hardware requirements for local on-premises version

If Oracle Database isn’t an option for you, there are many other alternative database management systems to choose from. SAP and IBM are among the best-known providers of database systems besides Oracle:

• SAP HANA
• IBM Db2
• Amazon Relational Database Service (RDS)
• Amazon Aurora
• Microsoft SQL
• MySQL
• SQLite
• Azure SQL Database

Additionally, there are several free, open-source database management systems:

• MariaDB
• NoSQL
• InfluxDB as GPL license
• InnoDB
• CouchDB
• MongoDB
• PostgreSQL