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Static analysis techniques for software verification can be applied also in the scenario of query languages. In particular, the *Abstract interpretation framework has been extended to the field of query languages for relational databases as a way to support sound approximation techniques. The semantics of query languages can be tuned according to suitable abstractions of the concrete domain of data. The abstraction of relational database system has many interesting applications, in particular, for security purposes, such as fine grained access control, watermarking, etc.
How can static analysis be useful with query languages?
A: software verification

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The Somerset Levels (or Somerset Levels and Moors as they are less commonly but more correctly known) are a sparsely populated wetland area of central Somerset, between the Quantock and Mendip hills. They consist of marine clay levels along the coast, and the inland (often peat based) moors. The Levels are divided into two by the Polden Hills; land to the south is drained by the River Parrett while land to the north is drained by the River Axe and the River Brue. The total area of the Levels amounts to about 647.5 square kilometres (160,000 acres) and broadly corresponds to the administrative district of Sedgemoor but also includes the south west of Mendip district. Approximately 70% of the area is grassland and 30% is arable. Stretching about 32 kilometres (20 mi) inland, this expanse of flat land barely rises above sea level. Before it was drained, much of the land was under a shallow brackish sea in winter and was marsh land in summer. Drainage began with the Romans, and was restarted at various times: by the Anglo-Saxons; in the Middle Ages by the Glastonbury Abbey, from 1400–1770; and during the Second World War, with the construction of the Huntspill River. Pumping and management of water levels still continues.
who started drainage of the Somerset levels 
A: the Romans, and was restarted at various times: by the Anglo-Saxons

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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]
What type of system in still prominent to this day?
A: relational systems

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Office buildings in Shanghai's financial district, including the Jin Mao Tower and the Hong Kong New World Tower, were evacuated. A receptionist at the Tibet Hotel in Chengdu said things were "calm" after the hotel evacuated its guests. Meanwhile, workers at a Ford plant in Sichuan were evacuated for about 10 minutes. Chengdu Shuangliu International Airport was shut down, and the control tower and regional radar control evacuated. One SilkAir flight was diverted and landed in Kunming as a result. Cathay Pacific delayed both legs of its quadruple daily Hong Kong to London route due to this disruption in air traffic services. Chengdu Shuangliu Airport reopened later on the evening of May 12, offering limited service as the airport began to be used as a staging area for relief operations.
What happened to office buildings in Shanghai?
A:
evacuated