Database Management Systems
From Isopedia
General Information About DBMS
A database management system (DBMS) is a program that is used to create, process, and administer a database. It is made up of many complex software programs that help assist in the organization and management of databases. Many companies of all different varieties use DBMS to facilitate their business operations and greatly improve their speed and efficiency of data storage, organization, and recovery. Three typical data modeling languages are used for DBMS organization; these include hierarchical, network, and relational models. The most appropriate model that a business or organization should use is not specific, but depends on the structure of the business or organization and their use of the DBMS. A database can provide one or all methods of organization, but depends on the supplier/maker of the DBMS. Each of the models mentioned above will be discussed further in the history of DBMS.
A major note that needs to be made concerning this topic of DBMS is that database management systems and databases are not the same thing. DBMS is simply a software program used to manage a database, while a database is a collection of table, relationships, and meta-data. Although each has their own respective, individualistic concepts, both must work together to help support business functions.
Types of DBMS
There are two major categories of DBMS. DBMS can be either enterprise DBMS or personal DBMS. Enterprise DBMS products support many users and are necessary for organizing large company databases in the business world. Many companies do not create their own database management systems, but license them from various providers. Some providers of DBMS include IBM, Oracle, and Microsoft. These individual providers will be discussed in greater detail later on. The other category of DBMS is personal DBMS. These DBMS products are designed for use by smaller groups of people, typically fewer than 15, but mostly for single users. They are used to perform smaller and simpler database application functions, unlike the larger complex application functions of enterprise DBMS products. A common personal DBMS is Microsoft Access, which comes as part of Microsoft Office Sweet.
Technical Functions of DBMS
Database management systems perform several important functions in relation to databases. DBMS products are used to create data models, including tables, relationships, and other structures of a database. Another function of DBMS is processing databases. Database management systems help application operations of inserting, changing, and deleting data. DBMS products are able to process databases using SQL or structured query language. This is a common, international standard language that all DBMS products accept and understand. SQL allows users to interact with databases, including applications such as querying, analyzing, and updating them. However, those individuals that are able to perform each of the previous stated tasks depend of the administrative function of DBMS, which will be discussed next. DBMS products are also critical in the administration of a database. Administration of databases is a broad concept and includes many different activities. These include backup and replication, rule enforcement, and security issues. Backup and replication is concerned with recovering data when it is lost due to equipment failure. Rule enforcement consists of applying rules to certain attributes, functions, and applications, which the DBMS will not allow. A final administrative issue that DBMS deal with is security. This involves setting limits for certain users or groups so as to protect the integrity of the business and its functions. Although there are many more functions and applications of DBMS, these are the major ones that need to be focused on when discussing database management systems.
History of Database Management Systems
Databases have been in use ever since computers were first born. Modern systems can be applied to widely different databases and needs. The majority of older systems were closely linked to the custom databases in order to gain speed at the cost of flexibility. At first DBMS were usually found in big businesses and organizations.
Navigational DBMS
When computers became more popular, database systems began to emerge, by the mid 60’s a lot of database systems became commercialized. CODASYL became the first commercial database system available. The Codasyl approach was based on the manual navigation of linked data sets which formed into large networks. This database system was not programmed to use the “Find” key or “Search” key. To us this sounds like it was useless, but back in the 60’s and 70’s it was much easier than storing data on magnetic tape. IBM established their own Database Management system in 1968, it was known as IMS. IMS was very similar to Codasyl, but it used a strict hierarchy for the model of its data navigation instead of Codasyl's network model. In the later 70’s and early 80’s both concepts became known as navigational databases because of the way data was able to be accessed.
Relational DBMS
In the late 70’s a man named Edgar Codd who worked at IBM, was unhappy with the navigational model of the Codasyl approach because of its lack of a “search”. In 1970, he wrote papers that outlined a new approach to database construction that eventually became known as a Relational Model of Data for Large Shared Data Banks. He described a new system for storing large sums of information instead of records being stored in a linked list of free form records as in Codasyl. Codd wanted to use a “table” of fixed length records, a way which would better organize the information, and also make it easier to find. This relational model splits up data into a series of normalized tables.
SQL DBMS
Around the same time that Codd wrote his outline for the Relational Model, IBM started working on a prototype system based on Codd's concepts as System R in the 70’s. Because this went contrary to Codd’s ideas, this project was handed out to a group of programmers who were not under Codd’s guidance. These programmers did not understand Codd’s ideas so they did it their own way. They violated several fundamentals of the relational model. In 1979 these programmers finished their work on multi table systems in which the data could be broken down so that all of the data for a record did not have to be stored on a large page of floating information. They soon established a query language called SQL. Codd’s ideas began to dominate that of Codasyl. IBM was encouraged to produce System R known as SQL/DS or Database 2.
Current Business That Use Database Management Systems
Businesses today have more responsibility and accountability than previous industries and firms ever had. To keep up with such a demand many companies are changing their systems in order to account for these radical changes. From terrorism and security threats to more advanced data and information, companies are forced to keep changing and altering their databases in order to keep up. Two major companies that are taking this step into the future are AC Nielson and Morgan Stanley.
AC Nielson is one of the worlds leading market information providers, not only does AC Nielson provide marketplace analysis and dynamics, but they do it in over 100 countries. By analyzing and studying the data AC Nielson can help understand their competition and even help them with future business strategies and goals. With so many statistics it is possible for AC Nielson to go through over 100 million rows of data every week. As the company continues to grow it is obvious that this number will continue to increase. Realizing the amount and wealth of information that is received by AC Nielson on a daily basis they began a plan to upgrade their database. Since the early 1980’s AC Nielson has been relying on a mainframe database legacy system to process all of this information. When AC Nielson first used this database they planned on using a low processing cost, which allowed them to only process a small number of companies. AC Nielson is not currently switching to a new IMB-AIX based server that runs oracle databases, this will not only increase the number of CPU’s but will also increase the number of servers as well. AC Nielson has stated that Oracle is very committed to the project has been helping to make sure that AC Nielson is taking full advantage of all the technology offered to them.
Another company that has utilized database technology in the new millennium is Morgan Stanley. Since 1993, Morgan Stanley, an international financial services firm, has been using Kerberos 4. Kerberos helped Morgan Stanley with solving the classic security problems of clear text passwords and single sign-on. However, with Morgan Stanley's specialized requirements and other new security threats in recent years, Kerberos ran into problems that led them to re-evaluate and rebuild Kerberos. The result of this was Kerberos 5. Kerberos 5 is an industry-standard network authentication protocol, which was designed at the Massachusetts Institute of Technology. Kerberos 5 is a feature of Windows 2000 and will be shipped as part of the operating system to provide secure, interoperable network authentication services to IT professionals. With Kerberos 5 security can be more secure with customers working in a mixed environment of clients. In addition, servers from both Microsoft and CyberSafe can benefit from secured communications and data transfers, accessible only by Kerberos validation. Morgan Stanley Dean Witter Institutional Securities relies on Kerberos and stated that with Kerberos 5, their security is now some of the best in the world.
Overall databases are an essential part to companies around the world. Without them millions of rows of data analysis, or things as simple as passwords would not be safe. It is apparent that as times change so do the requirements for the databases and security. As databases have changed to help suit our needs they will continue to do so in the years to come to help keep our data and information safe and secure
Substitutes for Database Management systems
Oracle- Manages databases which have relational characteristics
DB2- is an IBM line of Relational Database Management system. Can work on devices ranging from handhelds to mainframe
Microsoft Access- A product of Microsoft, it combines Microsoft’s jet database engine with graphic user interface
Microsoft SQL Server- A product of Microsoft, typically used by businesses of small to medium size database
My SQL- Owned by a Swedish company, is a free product but sells support and service contracts
Filemaker pro- a cross-platform database application from Filemaker inc.(subsidiary of Apple Inc.) Allows users to modify database by dragging elements into interface screens
Apache Derby- a Java relational DBMS, used for online transaction processing, is an open Source. Also distributed as IBM Cloudscape and Sun Java DB
Berkeley DB- is a high performance embedded database library. It was developed at U.C. Berkeley
Cache- is a proprietary M technology-based database management system from InterSystems. It stores data in multidimensional arrays capable of carrying hierarchically structured data.
D Base- the first widely used DMS
Firebird – a RDMS, it offers many ANSL SQL features, it is programmed by Firebird project at Source Forge
H2- A RDBMS written within Java, it can be run in Java or in client-server mode
Helix – pioneered by Apple, an easy to use system, it allows for non-programmers to construct sophisticated applications.
Others include:
Inflormix, Ingres, InterBase, NonStop SQL, OpenLink Virtuoso, Oracle Rdb, Paradox, Perst, Open Office.org Base, SQLite, Sybase, Teradata, PostgreSQL, Visual FoxPro,
Advantages and Disadvantages of Database Management Systems
Advantages: Control of data redundancy, Data consistency, More information from the same amount of data, sharing of data, improved data integrity, improved security, enforcement of standards, economy of scale, balance of conflicting requirements, improved data accessibility and responsiveness, increased productivity, improved maintenance through data independence, increased concurrency, and improved backup and recovery services
Disadvantages: Complexity, Size, Cost of DBMS’s, Additional hardware costs, cost of conversion, performance, higher impact of failure
The Future of Database Management Systems
The future of Database Management systems exists within Object-Oriented Database Management Systems. In an Object-Oriented Database Management System, information is represented in the form of objects. Object Database Management Systems make database objects appear as programming language objects in one or more object programming languages. An ODBMS extends this language with transparently persistent data, concurrency control, data recovery, associative queries, and other capabilities. ODBMS are faster, and superior than regular Database Management Systems in the following areas: -Complex Relationships -Complex Data -Distributed Databases -Multiple Languages or Platforms -Repetitive use of Large Working Sets of Objects -Massive Scalability -No Mapping Layer
ODBMS is frequently making updates to adjust to new available technologies, while frequently becoming more affordable and easier to use.
Another possible alternative to DBMS products also seems to be on the horizon. One current way of communicating between businesses today is through XML documents or eXtensible markup language documents. Using XML documents, businesses can communicate information to each other using standardized documents that allow for common formatting between business functions. Despite the rise in productivity and success of XML, there still remain several problems that need to be corrected before DBMS products are a thing of the past. Some current problems lie in the fact that there is no current way of efficiently querying stores of XML documents, there is no way to process duplicated data, and there is no conversion currently available to make XML data fit to table-oriented programs, such as Excel. Despite these current problems, the future of XML data storage looks very promising.
Sources
Web
http://sql-server-performance.bitpipe.com/olist/Database-Management-Software.html
http://en.wikipedia.org/wiki/Database
http://www.vldb.org/conf/2000/P663.pdf
Book
Using MIS by David M. Kroenke
Encyclopedia
Database Systems A practical approach to design Implimentation, and Management second edition
Team Members
Tim McMullen
Kerr McLeod
Daniel Escobar
Emmanuel Ephie
Mark Batorski
