Different Types of Database management systems Essay Example for Free

Different Types of Database management systems Essay A Database is a collection of records. Database management systems are designed as the means of managing all the records. Database Management is a software system that uses a standard method and running queries with some of them designed for the oversight and proper control of databases. Types of Database Management Systems: There are four structural types of database management systems: * Hierarchical databases. * Network databases. * Relational databases. * Object-oriented databases Hierarchical Databases (DBMS) : In the Hierarchical Database Model we have to learn about the databases. It is very fast and simple. In a hierarchical database, records contain information about there groups of parent/child relationships, just like as a tree structure. The structure implies that a record can have also a repeating information. In this structure Data follows a series of records, It is a set of field values attached to it. It collects all records together as a record type. These record types are the equivalent of tables in the relational model, and with the individual records being the equivalent of rows. To create links between these record types, the hierarchical model uses these type Relationships. Advantage: Hierarchical database can be accessed and updated rapidly because in this model structure is like as a tree and the relationships between records are defined in advance. This feature is a two-edged. Disadvantage : This type of database structure is that each child in the tree may have only one parent, and relationships or linkages between children are not permitted, even if they make sense from a logical standpoint. Hierarchical databases are so in their design. it can adding a new field or record requires that the entire database be redefined. Network Database: A network databases are mainly used on a large digital computers. It more connections can be made between different types of data, network databases are considered more efficiency It contains limitations must be considered when we have to use this kind of database. It is Similar to the hierarchical databases, network databases .Network databases are similar to hierarchical databases by also having a hierarchical structure. A network database looks more like a cobweb or interconnected network of records. In network databases, children are called members and parents are called occupier. The difference between each child or member can have more than one parent. The Approval of the network data model similar with the esteem of the hierarchical data model. Some data were more naturally modeled with more than one parent per child. The network model authorized the modeling of many-to-many relationships in data. The network model is very similar to the hierarchical model really. Actually the hierarchical model is a subset of the network model. However, instead of using a single-parent tree hierarchy, the network model uses set theory to provide a tree-like hierarchy with the exception that child tables were allowed to have more than one parent. It supports many-to-many relationships.

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Srijana Chhetri Mr. Wesney Honors World History Dec.18, 2013 Industrial Revolution in England The Industrial Revolution began in England towards the late 17th century. It started in the United Kingdom and was driven by a technology system based on water power and steam engines, cotton, textiles, ironworking, river transport, and canals. These inventions made it possible to send heavy commodities such as coal, iron, wool, grain and so forth from one end of the world to another (Henderson 1, The Industrial... 1815-1914). Inventors of new machines were honored and inventions of new technology were encouraged during this time period. Ordinary working people found increased opportunities for work within the new mills and factories, but these were always accompanied by strict working conditions with long hours of labor, and often involved young children and women. The Industrial Revolution replaced an economy based on agriculture with one based on industry and manufacturing. One of the most important changes was the continuous expansion of the population and the economy. Most obse rvers in the 18th century did not believe that expansion of the population and the economy could be sustained indefinitely. Thomas Malthus argued that population naturally grows faster than the food supply, and, therefore, malnutrition, famine, and disease would correct the imbalance (Trebilcock 397-398). However, this did not take place because of the continued expansion of the Industrial Revolution. The Industrial Revolution also gave an advantage to the government because the states in Europe issued tariffs to gain money, and as big companies emerged, they were required to register with the government and publish an annual budget. The societies during this ... ...e to the lack of better medicines. We could still be using subsistence agriculture to feed our family rather than commercial agriculture. Every human being on this earth should appreciate the fact that this event occurred because it has made their life so much easier and better compared to the life before the pre- industrial time. Even if some other huge revolution had occurred, instead of the Industrial Revolution, it would never be able to bring the same impact that this revolution was able to bring. The Industrial Revolution allowed people to save time with the new inventions, and also created more interactions in the global world with trade. There is no doubt that it was one of the most influential time periods of human history and most responsible for propelling society into the modern economies that we still have in place today.

Chapter 2 Ap World History Summary

Chapter 2 AP World History Summery Each civilization faces challenges from politics to environment and everything in between. This chapter explains how each society became urbanized even though it was very tough. Nubia, China, Olmec, and Chavin are connected though each are separated by millions of miles and geological isolation. In China, dynasties rule all over the land; the Shang dynasty begins China’s history with the rise of power of it’s clans. It contains the earliest recorded writing documents, and they introduced bronze during 2000 B.C. E. The region was ran by a warrior aristocracy who loved warfare, hunting, exchanging, feasting, and wine revelry; the King of Shang always traveled for courts of his subordinates to reinforce their loyalty. Nomadic people that owned desert regions, or steppe lands were given demonstration power also. Religion in the Shang dynasty was enforced, the Kings used divination to determine the will of their ancestors and Gods to win fa vor. Nubia is located in the Nile River Valley and was over run by the Egyptians because of they have gold mines.After Egypt took charge, Nubia became Kush and adapted the Egyptian culture. Nubia decided to help local Palestine who struggled with the Assyrians in 701 B. C. E. ; this was a mistake because the Assyrians invaded and overthrown Egypt so that made a downfall for Nubia. After a while, Nubia became in control again, they still kept the Egyptian language, however Sub-Saharan culture replaced the Egyptian culture when Meroe became better suited for agriculture and trade. On the other side of the world, the Olmec civilization is completely isolated from the world.It’s located in Mesoamerica which is one of the most impressive early civilizations. The King’s Power was used to make people build large scale irrigation and drainage works, and by the 1000 B. C. E, they have become a civilization. In addition to the geological isolation, Olmec have frequent volcanic e ruptions and earth quakes, and mountains that separate the region into micro environments. Evolution developed into urbanization and appearance of powerful political and religious elites. The people were very advanced for their time; they made he calendar and based their urban centers to reflect astronomical observations. The Olmec civilization influenced the Mayans and considered the most influential earliest Mesoamerican civilization. The most impressive early Urban South American civilization is Chavin. It’s home to the most dense population. Maize increased the food supply of the coast and interior foothills, thus, allowing greater leverage for civilization. They have a form of political integration and trade dependency on it’s neighbors that may have relied on military force.Their religion was based on praising their royal ancestors and gods that can take on animal form. The most praised animal is the Jaguar; human sacrifices were made at temple platforms. These c ivilizations became very complex as they advance with technologies, science, and math mathematics. Power was taken away, and given to in each society, and some are diminishing before us. They may be separated and isolated from each other by mountains, water, and hemispheres, but that doesn't separate the development of each economic institutions politically, socially, and economically.

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