MOD

In order to represent inheritance, several recent designs for database programming languages have made use of class construct, which can be thought of as a restricted data type with an associated set of instances. Moreover, these classes are persistent ...

This paper surveys and compares various strategies for processing logic queries in relational databases. The survey and comparison is limited to the case of Horn Clauses with evaluable predicates but without function symbols. The paper is organized in ...

This article presents an algorithm to refresh the contents of database snapshots. A database snapshot is a read-only table whose contents are extracted from other tables in the database. The snapshot contents can be periodically refreshed to reflect the ...

Query processing can be sped up by keeping frequently accessed users' views materialized. However, the need to access base relations in response to queries can be avoided only if the materialized view is adequately maintained. We propose a method in ...

There are many examples of actions on abstract data types which can be correctly implemented with nonserializable and nonrecoverable schedules of reads and writes. We examine a model of multiple layers of abstraction that explains this phenomenon and ...

Few database query optimizer models have been validated against actual performance. This paper presents the methodology and results of a thorough validation of the optimizer and evaluation of the performance of the experimental distributed relational ...

A prototype of a temporal database management system was built by extending Ingres. It supports the temporal query language TQuel, a superset of Quel, handling four types of database static, rollback, historical and temporal. A benchmark set of queries ...

Most previous work on query optimization in distributed database systems has focused on finding optimal or near-optimal processing plans based solely on static system characteristics, and few researchers have addressed the problem of copy selection when ...

A database token is a value of either the data or the metadata. Usually, such tokens are combined with formal language constructs to form queries. In this paper we show how a given set of tokens may be completed to a proper query. This process provides ...

Even though many of the essential notions of hypertext were first contained in the description of a “memex,” written by Vannevar Bush in 1945 [Bus45], there are today only a few scattered implementations of hypertext, let alone any serious use of it in ...

Improvements both in technology and in user-oriented software have shown the feasibility of new kinds of non-procedural languages. However, interaction between end-user and data should rely more and more on graphical languages and, particularly, on '...

In the past few years we have seen in the literature a number of proposals for benchmarks to be used in measuring the performance of database management and transaction processing systems. The TP1 benchmark [Anon et al 1985] and the Wisconsin benchmark [...

Many capabilities that are needed for recursive applications in engineering and project management are not well supported by the usual formulations of recursion. We identify a class of recursions called “traversal recursions” (which model traversals of ...

The authors introduce a new method to compile queries referencing recursively defined predicates. This method is based on an interpretation of the query and the relations as functions which map one column of a relation to another column. It is shown ...

New implementation techniques and new capabilities for database systems are being developed and proposed at a rapid rate. Novel file structures and improved algorithms for query optimization, buffer and recovery management, and transaction management ...

In some recently proposed extensions to relational database systems as well as in deductive databases, a database system is presented with a collection of queries to process instead of just one. It is an interesting problem then, to come up with ...

Over the last decade many techniques for optimizing relational queries have been developed. However, the problem of translating these set-oriented query specifications into other forms for efficient execution has received little attention.

This paper ...

In this paper a method is proposed how to achieve response times of main memory database systems without keeping the whole database in main memory. The method was originally developed for real-time systems in manufacturing automation, but it is ...

Multiattribute hashing and its variations have been proposed for partial match and range queries in the past. The main idea is that each record yields a bitstring @@@@ (“record signature”), according to the values of its attributes. The binary value (@@@...

Most previous work in the area of main memory database systems has focused on the problem of developing query processing techniques that work well with a very large buffer pool. In this paper, we address query processing issues for memory resident ...

Consider a file which arranges records in sequential order, and stores them with possible empty spaces in M consecutive pages of memory. We develop an insertion-deletion algorithm which runs in a worst-case time approximately proportional to log²M ...

This paper describes the rule base management strategy of an expert system environment. The environment includes a set of integrated tools which facilitate acquisition, manipulation and maintenance of knowledge. The rule base management component of the ...

We study here automated deduction in databases in the presence of various types of inference rules of the form of Horn Clauses with Skolem functions. These inference rules are typical for databases with incomplete information. We demonstrate a number of ...

A rule-based object/task modelling approach is proposed which is characterized by specifying object behaviors and domain rules in terms of object-oriented logic programming, and specifying tasks and meta-rules in terms of network-oriented formalism. In ...

Large multimedia data bases become feasible due to recent advances in hardware technology. A very important component of multimedia data base management systems will be the presentation manager which will be responsible for effective multimedia ...

This paper identifies data modelling and data access and sharing requirements which multimedia applications impose on a database system. It shows the capabilities of an object-based data model and indicates extensions which are needed to meet the data ...

DBMSs must offer spatial query processing capabilities to meet the needs of applications such as cartography, geographic information processing and CAD. Many data structures and algorithms that process grid representations of spatial data have appeared ...