Context and question: The relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links. The relational model employs sets of ledger-style tables, each used for a different type of entity. Only in the mid-1980s did computing hardware become powerful enough to allow the wide deployment of relational systems (DBMSs plus applications). By the early 1990s, however, relational systems dominated in all large-scale data processing applications, and as of 2015[update] they remain dominant : IBM DB2, Oracle, MySQL and Microsoft SQL Server are the top DBMS. The dominant database language, standardised SQL for the relational model, has influenced database languages for other data models.[citation needed]
Who created the relational model of DBMS?
Answer: Edgar F. Codd
Context and question: However, early farmers were also adversely affected in times of famine, such as may be caused by drought or pests. In instances where agriculture had become the predominant way of life, the sensitivity to these shortages could be particularly acute, affecting agrarian populations to an extent that otherwise may not have been routinely experienced by prior hunter-gatherer communities. Nevertheless, agrarian communities generally proved successful, and their growth and the expansion of territory under cultivation continued.
What were the causes of cultivation in early farm towns?
Answer: unanswerable
Context and question: While many secular buildings exist from the Late Middle Ages, it is in the buildings of cathedrals and great churches that Gothic architecture displays its pertinent structures and characteristics to the fullest advantage. A Gothic cathedral or abbey was, prior to the 20th century, generally the landmark building in its town, rising high above all the domestic structures and often surmounted by one or more towers and pinnacles and perhaps tall spires. These cathedrals were the skyscrapers of that day and would have been the largest buildings by far that Europeans would ever have seen. It is in the architecture of these Gothic churches that a unique combination of existing technologies established the emergence of a new building style. Those technologies were the ogival or pointed arch, the ribbed vault, and the buttress.
What is an example of architectural technology that is seen in Gothic construction?
Answer:
the ribbed vault