ALERT

[FREE DEMO] Deploy Your Enterprise Cloud in Minutes

Three-Schema Architecture

Definition - What does Three-Schema Architecture mean?

Three-schema architecture is an idea in relational database design that breaks a database down into three different categories according to its use and structure, and to the roles played by system administrators, designers and end users.

Techopedia explains Three-Schema Architecture

Developed in the 1970s, the three-schema architecture helps to evaluate a relational database from different vantage points. The first of the three levels is called the external level or user level. This is the view of the relational database that end users see, and it involves a high level of abstraction. The second level is the logical schema or conceptual level, where designers work. The third level is the physical schema or physical level, where programmers maintain a database on a hardware system. The three-schema architecture is generally attributed to the ANSI/SPARC group and is sometimes also called "ANSI/SPARC" architecture.

Part of the usage of the three-schema architecture is to look at how the design maintenance differs from the core system maintenance. For example, items dealing with database tables and queries belong in the conceptual or logical schema, where issues such as memory handling are looked at in the physical level. Some IT experts talk about the three-schema architecture in the context of changing levels without affecting other levels or in terms of data independence. In addition, the three-schema architecture also performs a breakdown of the core duties of database designers, network administrators or server maintenance teams.

Techopedia Deals

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
Tweat cdn.techopedia.com
"Techopedia" on Twitter


'@Techopedia'
Sign up for Techopedia's Free Newsletter!

Email Newsletter

Join thousands of others with our weekly newsletter

Resources
The 4th Era of IT Infrastructure: Superconverged Systems
The 4th Era of IT Infrastructure: Superconverged Systems:
Learn the benefits and limitations of the 3 generations of IT infrastructure – siloed, converged and hyperconverged – and discover how the 4th...
Approaches and Benefits of Network Virtualization
Approaches and Benefits of Network Virtualization:
Businesses today aspire to achieve a software-defined datacenter (SDDC) to enhance business agility and reduce operational complexity. However, the...
Free E-Book: Public Cloud Guide
Free E-Book: Public Cloud Guide:
This white paper is for leaders of Operations, Engineering, or Infrastructure teams who are creating or executing an IT roadmap.
Free Tool: Virtual Health Monitor
Free Tool: Virtual Health Monitor:
Virtual Health Monitor is a free virtualization monitoring and reporting tool for VMware, Hyper-V, RHEV, and XenServer environments.
Free 30 Day Trial – Turbonomic
Free 30 Day Trial – Turbonomic:
Turbonomic delivers an autonomic platform where virtual and cloud environments self-manage in real-time to assure application performance.