Often We Listen That Database Of This Website Was hacked.So What Is Database?
- Database is a repository or collection of logically related, and similar data. Database stores similar kind of data that is organized in a manner that the information can be derived from it, modified, data added, or deleted to it, and used when needed.
- Some examples of databases in real life situations are:
o It provides a clear representation of iterations and overlapping phases.
o The model emphasizes the reusability of the source code.
o The circles depict the overlapping phases.
o The arrows within circles depicts iterations within the phases.
o Changes can be easily made between class specification and requirement specification.
o So no need to freeze the requirements in the early phases of software developmen.
o System is developed in terms of classes.
o Phases can be applied to individual classes.
- Overlapping phases
- Short maintenance cycle
- Can easily accommodate changing
- Supports reusability
- Undisciplined software development approach in which the developer moves randomly between phases.
- It is point to point connection with only the two devices on either side of it.
- Signal passed along the ring in one direction, from device to device until it reaches its destination.
- Each device in ring communicate with repeater (repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances).
- The ring topology is continues path for data with no logical beginning or ending point and thus no terminators.
- Network may be either unidirectional or bidirectional.
Advantages of ring topology
It is easy to install and configure.
Every computer is given equal access to the ring. No single computer can monopolies the network.
Disadvantage of ring topology
Failure in any cable or node breaks the loop and can take down the entire network.
Maximum ring length and number of nodes are limited.
- Small change in electronic components, increase in power of microprocessor and increase in capacity of main memory and hard disk continued during fifth generation.
- VLSI became ULSI (Ultra Large Scale Integration) in fifth generation and chips having ten million electronic component.
- Storage technology also increased during this fifth generation, optical disk also emerged as a popular portable mass storage media such as CD-ROM.
- In fifth generation outgrowth of computer network, this trend is result in popularity of internet. Internet provide computer user to sitting across the globe to communicate with each other within a minutes using Electronic Mail.
- Some application emerged during this time e.g. Electronic commerce, Virtual libraries, virtual classrooms, distance education.
- Popular tool for wide range for multimedia (text, graphics, animation, audio, video) application because high processing power and storage capacity.
- The data size of multimedia application is much larger than textual information because representation of graphics, animation, audio, video.
- The way in which the connections are made (shape of network) is called topology of network.
- Geometric representation of the relationship of all the links and linking devices.
* Network topology
- Refers to physical layout of the network, the location of the computer and how cable is run between them.
* Physical topologies: describe how the cables are run.
* Logical topologies: describe how the network messages travel.
* Types Of Physical Topology