A Brief Overview of Database Management Systems

Database Management Systems, abbreviated as DBMS and can be categorized based on type as Hierarchical, Network, Object Oriented and Relational systems. In hierarchical databases, data is structured in the form a top-down tree, where a parent node has multiple child nodes. Network DB is very similar to hierarchical database, except for a child node can have multiple parent nodes, thus forming a network as opposed to hierarchical tree. Relational DBS are the most commonly used, where data is structured as rows and columns in tables and relations specified between tables. Object oriented database enables the usage of multimedia (audio, video, pictures etc) referred to as objects and also comprise a set of instructions in the form of software programs allowing operations on those objects. Today, the most popular and widely used databases are relational databases, allowing ease in retrieval of stored data. Examples of relational DB are Microsoft SQL Server, Microsoft Access, Oracle, IBM DB2 etc. Relational DB allows rapid data storage and retrieval. Data structures can be defined in order to manage information flow and business operations. Also, in a relational DB integrity constraints may be defined to restrict data type, access, capacity, property etc in any fields. In every table a set of constraints determine how and where data from that table can be used. Using keys data in a particular column can be defined to contain only unique values; this type of key is called a primary key. A foreign key can be referred to from another table. There are many other type of keys which can be used on columns of a table. Relational DBs are highly dynamic and consist of wide range of operations that can be performed on stored data. Mathematical functions make it extremely easy to find sum, average, minimum, maximum etc from a given set of values, there are many advanced functions available. Using joins, data from multiple tables can be joined in order to show only relevant information to a user at any point of time. Conversion and Date functions are extremely helpful while working with data other than numbers and characters. SQL Server Management Studio is a relational DBMS by Microsoft. Apart from the above mentioned features of relational DBs, it also can be configured as a reporting server (SSRS). SQL Server Reporting Services is a web based reporting tool from Microsoft that can be used to create reports. In addition SSIS (SQL Server Integration Services) allow SQL Server to be used as a ETL (Extract-Transform-Load) tool, thus facilitating analytics, business intelligence and decision making.