Titlebook: Database Programming Languages; 6th International Wo Sophie Cluet,Rick Hull Conference proceedings 1998 Springer-Verlag Berlin Heidelberg 1

POWER

Querying sequence databases with transducers,nown complexity classes, such as polynomial time and hyper-exponential time. We establish a tight relationship between levels in this hierarchy and the depth of subroutine calls within Transducer Datalog programs. Finally, we show that Transducer Datalog programs of arbitrary depth express exactly t

雪白

A structure-based approach to querying semi-structured data,duced graph schemas [BDFS97]. A storage schema splits the graph‘s edges into several relations, some of which may have labels of known types (such as strings or integers) while others may be still dynamically typed. We show here that all positive queries in UnQL, a query language for semistructured

Hypomania

Adornment

Incremental recomputation of recursive queries with nested sets and aggregate functions,, is still maintainable using only fiat relations. We also show that one does not need auxiliary relations of arity more than 2. In particular, this implies that the recursive queries maintainable in the nested language with aggregates, can be also maintained in a practical relational database syste

PANG

瑪瑙

Burkhard Schnepel,Edward A. Alpersnt system can capture subtleties that go far beyond the level of expressiveness of object-oriented type systems. The temporal nature of the language and its distinctive orthogonal model of persistence make this language system successful in handling a variety of non-trivial applications.

打火石

Alan Wassyng,Mark Lawford,Tom Maibaum preliminary results on the expressiveness of hybrid languages. In particular, we show that relatively simple hybrid languages are able to define all finite structures expressed by skolemized universally quantified second-order formulae with some constraints on the quantified predicates.

Inflamed

Kun Wei,Jim Woodcock,Alan Burnsthe introduction and elimination of aggregation functions, and the promotion of aggregation functions through iteration operations. We also show how some of these equivalences can be used to optimise comprehensions, a high-level query construct supported by many database languages.

爭(zhēng)吵

RALES