Data Security
The DBMS can prevent unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database or a subset of it known as a "subschema." For example, in an employee database, some users may be able to view salaries while others may view only work history and medical data.
Data Integrity
The DBMS can ensure that no more than one user can update the same record at the same time. It can keep duplicate records out of the database; for example, no two customers with the same customer number can be entered.
Interactive Query
A DBMS provides a query language and report writer that lets users interactively interrogate the database. These essential components give users access to all management information as needed. See query language and report writer.
Interactive Data Entry and Updating
A DBMS typically provides a way to interactively enter and edit data, allowing you to manage your own files and databases. However, interactive operation does not leave an audit trail and does not provide the controls necessary in a large organization. These controls must be programmed into the data entry and update programs of the application.
This is a common misconception about using a desktop computer DBMS. Creating lists of data for a user's own record keeping is one thing. However, although complete information systems can be developed with such software, it cannot be done without understanding how transactions and files relate to each other in a business system (see Database Design below). In addition, some type of programming is required, whether at a graphical drag and drop level or by using traditional languages.
Data Independence
When a DBMS is used, the details of the data structure are not stated in each application program. The program asks the DBMS for data by field name; for example, a coded equivalent of "give me customer name and balance due" would be sent to the DBMS. Without a DBMS, the programmer must reserve space for the full structure of the record in the program. Any change in data structure requires changing all application programs.
Top 5 Data definition
Data is a collection of distinct pieces of information, particularly information that has been formatted (i.e., organized) in some specific way for use in analysis or making decisions.
- NYSE Launches Cloud Platform for Traders – NYSE Euronext today entered the cloud computing business, launching a platform that allows financial traders to lease computing power at the NYSE’s new data center in northern New Jersey. The new platform, operated by NYSE Technologies, was developed with technology from VMware and EMC.
- Apple Confirms the Approach of the iCloud – Apple today confirmed that it will announce details for “iCloud, Apple’s upcoming cloud services offering,” at the company’s annual Worldwide Developers Conference next Monday. The announcement confirms the long-held assumption that the size of Apple’s new data center in North Carolina was a sure sign of a coming cloud offering.
- Power Usage Effectiveness 2 – The Sequel – On May 17th the Data Center Efficiency Task Force issued a 14 page document entitled “Recommendations for Measuring and Reporting Version 2 – Measuring PUE for Data Centers” – also known as PUE 2. The updated PUE version is meant to clarify and reiterate the updated measurement requirements of the PUE metric and presumably prevent “PUE envy.”
- Bid to Extend Washington State Tax Break Fails – A bill in Washington state that would have extended a key sales tax exemption for data center construction has died, meaning the tax break will expire at the end of this month. The bill passed the Senate 41-1 and moved out of the House Ways Committee via a unanimous vote, but never came up for a vote in the House.
- Tornado Risk Seen for Social Security Project – The Social Security Administration has elected to build its new $800 million data center to withstand wind speeds of only 90 miles an hour, rather than the 120 miles an hour standard common in most mission critical facilities.
PotgreSQL is a open source object-relational database system. It runs on most *nix flavours, Windows and Mac OS. This has full support for joins, views, triggers, stored procedures etc.,
Oracle is the best database for any mission critical commercial application. Oracle has following 
SQLite does not work like a traditional client-server model with standalone process. Instead, it is a self-contained, server-less SQL database engine.