[7] DB2 traces its roots back to the beginning of the 1970s, when Edgar F. Codd, a researcher working for IBM, described the theory of relational databases, and in June 1970, published the model for data manipulation.

This led to an inexact interpretation of Codd's relational model that matched only part of the prescriptions of the theory; the result was Structured English QUEry Language or SEQUEL.

IBM bought Metaphor Computer Systems to utilize their GUI interface and encapsulating SQL platform that had already been in use since the mid-80s.

In 1976, IBM released Query by Example for the VM platform where the table-oriented front-end produced a linear-syntax language that drove transactions to its relational database.

An earlier version of the code that would become DB2 LUW (Linux, Unix, Windows) was part of an Extended Edition component of OS/2 called Database Manager.

(Note that DRDA is based on objects and protocols defined by Distributed Data Management Architecture (DDM).)

In the mid-1990s, IBM released a clustered DB2 implementation called DB2 Parallel Edition, which initially ran on AIX.

This edition allowed scalability by providing a shared-nothing architecture, in which a single large database is partitioned across multiple DB2 servers that communicate over a high-speed interconnect.

Other enhancements include OLTP-related improvements for distributed platforms, business intelligence/data warehousing-related improvements for z/OS, more self-tuning and self-managing features, additional 64-bit exploitation (especially for virtual storage on z/OS), stored procedure performance enhancements for z/OS, and continued convergence of the SQL vocabularies between z/OS and distributed platforms.

There were three key themes for the release, Simplified Management, Business Critical Reliability, and Agile XML development.

DB2 9.7 also enhanced its concurrency model to exhibit behavior that is familiar to users of Oracle Database and Microsoft SQL Server.

DB2 pureScale is a cluster database for non-mainframe platforms, suitable for online transaction processing (OLTP) workloads.

IBM based the design of DB2 pureScale on the Parallel Sysplex implementation of DB2 data sharing on the mainframe.

A DB2 pureScale system can grow to 128 database servers, and provides continuous availability and automatic load balancing.

In early 2012, IBM announced the next version of DB2, DB2 10.1 (code name Galileo) for Linux, UNIX, and Windows.

It added, e.g., RESTful services; and usage of AI to optimize the selection of the access path to the data, thus enhancing performance.

Traditional transaction processing databases were not able to provide the insight business leaders needed to make data-informed decisions.

Db2 Warehouse, with its capabilities to normalize data from multiple sources, performs sophisticated analytic and statistical modeling, provides businesses these features at speed and scale.

Initially purposed for star and snowflake schemas, Db2 Warehouse now includes support for the following data types and analytical models, among others: Db2 Warehouse uses Docker containers to run in multiple environments: on-premise, private cloud and a variety of public clouds, both managed and unmanaged.

Additional benefits include low latency, high performance, security, SQL compatibility and federation capabilities.

Db2 Event Store targets the needs of the Internet of things (IOT), industrial, telecommunications, financial services, online retail and other industries needing to perform real-time analytics on streamed high volume, high velocity data.

It can store and analyze 250 billion events in a day with just 3 server nodes with its high speed data capture and analytics capabilities.

The need to support AI and machine learning was envisioned from the start by including IBM Watson Studio into the product, and integrating Jupyter notebooks for collaborative app and model development.

It includes several BI features such as ETL, data mining, OLAP acceleration, and in-line analytics.

A prior free Db2 version, the IBM DB2 Express-C, supported up to 16 GB RAM and two CPU cores.

[31] The Db2 Standard Edition is available as a perpetual software license for production and non-production use for up to 16 processor cores and 128 GB RAM with IBM support.

The Db2 Advanced Edition is available only as a component of the IBM Hybrid Data Management Platform (HDMP).

Within HDMP, Db2 is available both as a perpetual software license AND a monthly subscription for unrestricted production and non-production use with premium IBM support.

FlexPoints are generic licensing credits that can be used to deploy any Db2-family software product or cloud service offering.

[clarification needed] Db2 has APIs for Rexx, PL/I, COBOL, RPG, Fortran, C++, C, Delphi, .NET CLI, Java, Python, Perl, PHP, Ruby, and many other programming languages.