The relational model is the basis for most modern databases, while SQL is the most commonly used query language. However, there are data structures and computational problems that cannot be expressed using SQL-92 queries. Among them are those concerned with the bill-of-material and corporate hierarchies. A newer standard, called the SQL-99, introduced recursive queries which can be used to solv...

Die Datenbankanfragesprache SQL hat sich zum Standardinstrument bei der Arbeit mit relationalen Datenbanken etabliert. Durch die weitreichende Standardisierung, v.a. im Rahmen von SQL-92 und SQL:1999, wurde eine sichere Basis gelegt, die von den meisten kommerziellen sowie freien Datenbankverwaltungssystemen (DBVS) als Anfrageschnittstelle unterstützt wird. Hinsichtlich der Umsetzung der Standa...

Viral hepatitis includes five distinct disease entities, which are caused by at least five different viruses. Hepatitis A and hepatitis B (infectious and serum hepatitis, respectively) are considered separate diseases and both can be diagnosed by a specific serologic test. Hepatitis C and E comprise a third category, each a distinct type, with Hepatitis C parenterally transmitted, and hepatitis...

Wanderwörter are a problematic set of words in historical linguistics. They usually make up a small proportion of the total vocabulary of individual languages, and only a minority of loanwords. They are, however, found frequently in languages from across the world. There is, to our knowledge, no general synthesis of Wanderwörter patterns, causes of exceptionally high borrowing rates for particu...

Triggers have been adopted as an important database feature and implemented by most major database vendors. Despite their diverse potential usages, one of the obstacles that hinder the triggers from its wide deployment is the lack of tools that aid users to create complex trigger rules in a simple manner. Although the majority of the users of triggers are DBAs or savvy end-users, writing trigge...

ion, to the ‘movement’ of a detached frog’s leg. A teaching of this type might be developed in a number of ways. It is of course consistent with its central thought that the dictates of this virtue might, in respect of a given pair of agents, be massively aVected by some of the so-called social practices under which the pair happen together to fall. Similarly, Hume’s doctrine is consistent with...

The lion's share of datalog features have been incorporated into the SQL3 standard proposal. However, most SQL manuals still recommend to implement user-de ned conditions for data integrity nondeclaratively, by triggers or stored procedures. We describe how to implement known declarative database technology for integrity checking in SQL databases. We show how to represent and evaluate arbitrari...