A Brief History of SQL and Database Management Systems
Last updated on Tue 17 Mar 2020
SQL stands for Structured Query Language. As the language that does the data manipulation, it is the backbone behind all of the major relational database management systems (RDBMS).
Brief History of SQL and its Implementations
Dr. E.F. Codd is widely considered the father of the RDMBS. He was the person who conceptualized the theory of relational databases in June of 1970 and created the model for data manipulation. Codd worked for IBM at the time, and they created the Structured English Query Language (SEQUEL) to apply his model. SEQUEL was already a trademarked name, so IBM switched the acronym to SQL, Structured Query Language, and it stands to this day.
IBM then began working on a prototype called System/R in 1974. It went through several phases and was eventually first released to the public as SQL/DS in 1981. It wasn't the first commercially available implementation of RDMBS and SQL, however; Relational Software beat IBM to the punch and released their product, Oracle, in 1979. More about that later.
SQL first became an ANSI standard in 1986. Several other national and international organizations first standardized it later in the 80s. ANSI has since revised it standards with SQL89(SQL1), SQL92(SQL2), and SQL99(SQL3).
SQL Today and the Big Players
There are 3 big players in the enterprise RDMBS market. Relation Software changed their name to Oracle, and their Oracle system still bills itself as the top of the line RDBMS. IBM is still a big player with their current version, DB/2, which runs on a wide range of platforms, too. Microsoft SQL Server is the other big enterprise player and has made huge strides in the RDBMS market, holding the record price/performance (tpmC benchmark) for any Windows database.
There are several entry-level to mid-market database systems out there, too. Some of them include MySQL, the most popular open-source RDBMS which continues to make huge strides in terms of performance, capability, and scalability. Microsoft Access isn't a true RDMBS, but it includes a lot of the same features, including SQL. Postgre, Paradox, and Firebird are some of the others available.
All of these products use SQL as the brains of their operations. Most vendors' products are SQL92-compliant. In addition, each vendor has their own flavor of SQL. For example, Oracle uses PL/SQL, SQL Server uses T-SQL, and Access used JET SQL. What this means is the vendor-specific additions add some enhancements to what their version of SQL can do to help differentiate their product.
SQL is broken down into 2 main categories, Data Definition Language (DDL) and Data Manipulation Language (DML).
DDL defines and manages the objects inside of your database. The SQL standard statements for DDL include CREATE, ALTER, and DROP.
DML is used to actually modify your data and includes statements like SELECT, INSERT, and UPDATE. It's interesting, SELECT statements don't actually modify any data, but since they aren't used to define the data and since they are typically used in conjunction with INSERT, UPDATE, and DELETE statements.
Future of SQL
The next standard for SQL is expected to improve Internet access to data, most notably with XML. Some vendors have already incorporated XML-specific operators to their flavor of SQL. They are also considering how to integrate object-oriented programming models into SQL. Again, the vendors are already ahead of the curve as the next version of SQL Server will have to capability to write queries using any .NET language.
SQL together with RDBMS continue to be the core of all business applications. It's always dangerous to say that the current way of doing things cannot be improved upon, but the combination has been very successful and popular for more than 20 years and shows no signs of going away.