DB Desk

  Relational Model (RM) represents the database as a collection of relationships. A relationship is nothing more than a table of values. Each row of the table represents a collection of related data values. These rows of the table denote a real-world entity or relationship. The table name and column names are useful for interpreting the meaning of the values in each row. Data are represented as a set of relationships. In the relational model, the data are stored as tables. However, the physical storage of data is independent of how data is organized logically. Some popular relational database management systems are: DB2 and Informix Dynamic Server – IBM Oracle and RDB – Oracle SQL Server and Access – Microsoft Concepts of relational model in DBMS Attribute: Each column in a table. Attributes are the properties that define a relationship. e.g. Student_Rollno, NAME, etc. Tables – In the Relational model the relationships are saved in table format. It ...

  Some of my friend ask me about there are some restrictions on accessing other features of DBMS on end users because he worked in an organization where all the features are not get accessed. Every user in the database has a role which is defined by the Database Administrator. Users use features according to there needs, many features are restricted due to insufficient privileges because special permissions are needed. Benefits of Database Privileges Normal user can’t delete your tables of harm your database. No extra queries will deployed save traffic and load. Nobody can seen the private data Except special peoples. Maintenance of database can easily be handle. Easy to access recent data and rollback. Attacks and brute force attacks saved. Easily banning and get back the privileges from Database Administrator.

  Data Consistency: Definition 1: Data consistency means that the changes made to the different occurrences of data should be controlled and managed in such a way that all the occurrences have the same value for any specific data item. Data inconsistency leads to a number of problems, including loss of information and incorrect results. In the database approach, it is controlled because data is shared and consistency is controlled and maintained. Data Consistency Definition 2: Data consistency meaning is the validity, accuracy and usability of related data. It ensures that each user observes a consistent(Same) view of the data, including changes made by the user’s own transactions and transactions of other users. Types of Data Consistency: Point in time consistency Transaction consistency Application consistency Data Inconsistncy: Data Inconsistency Definition: Data inconsistency meaning is that different versions of the same data appear in d...

  What is Software Testing? The software testing phase starts when you have done the coding and designing phase of the software. A developer first priority (after coding) is software testing to find the bugs. Testing is lifted to identify either all phases completed and to ensure the working, stability and quality of the software going to be delivered. Number of testing activities incorporated to find the possibility of any error or bugs to make it more reliable and bug free before releasing the software. Why software Testing is important? Software testing is to ensure the features of the software is gathered and completed. We have listed some of the software testing aspect why it is important. The software is according to the expectation of the client. The deliverable software is in working condition. software is client/user friendly. Software Development/Coding: Software development is actually the coding phase of the computer programming which is to build...

  Now a days almost all applications are based on OOP (object oriented programming); and use case diagrams depicts the functionality to be implemented in a system. On the other hand DFD (Data Flow Diagram) is the true depiction of OOP based programming.   Use Case & Data Flow Diagram are same? Use case diagrams and DFD are not contradicting each other as far as system architecture is concerned. DFD diagram and Use case diagram are used to view the system from different perspective/angle. A graphical representation of the flow of data or information in a system or part of system. It consists of data flows, processes, sources, destinations and stores. Difference Between Use Case & Data Flow Diagram A DFD(Data Flow Diagram) only shows the sources and destinations of data coming and going from the system and the transformation of data when it passes through some system process. A Use Case is used to capture the functional requirements of the system....

  What the difference between Flow charts and Flow Graph? why can't we utilize Flow charts for software testing? A program's flow charts resembles a control flow graph but there are some differences which are provided below: Difference: Flow Charts and Flow Graph 1. In flow graphs, we don't show the details of what is in a process block whereas in flow charts every part of the process block is drawn. 2. In flow charts, different types of nodes are represented by different symbols, but we do not use different symbols in control flow graphs. 3. The flow graph focuses on control flow of the program whereas the flowchart focuses on process steps and due to this reason, flow charts are not used for testing. What is Flow Charts  Graphic representation or Symbolic representation of process shown in the figure below called Flow charts. So different symbols are used to denote process which contains a little description of the process. These symbols are linked t...