ODE is a database system and environment based on the object paradigm. It offers one integrated data model for both database and general purpose manipulation. The database is defined, queried and manipulated in the database programming language O++ which is based on C++. O++ borrows and extends the object definition facility of C++, called the class. Classes support data encapsulation and multiple inheritance. We provide facilities for creating persistent and versioned objects, defining sets, and iterating over sets and clusters of persistent objects. We also provide facilities to associate constraints and triggers with objects. This paper presents the linguistic facilities provided in O++ and the data model it supports. 1. INTRODUCTION The object paradigm is a natural way of organizing data as it allows users to structure, retrieve and update data in terms of the application domain. ODE is a database system and environment based on the object paradigm. The database is defined, queri...

this paper, after a quick introduction to O++ in Section 2, we state our design goals in providing trigger and constraint facilities for an object-oriented database in Section 3. We then describe the constraint and trigger facilities in Ode and illustrate their use in Sections 4 through 6. We also discuss issues related to constraints and triggers such as intra-object versus inter-object constraints and triggers, and referential integrity. In Section 7 we give details about the implementation of Ode triggers and constraints. Finally, in Section 8, we discuss constraint and trigger facilities in other systems.

A Functional Database Phil Trinder D.Phil. Thesis Wolfson College Michaelmas Term, 1989 This thesis explores the use of functional languages to implement, manipulate and query databases. Implementing databases. A functional language is used to construct a database manager that allows efficient and concurrent access to shared data. In contrast to the locking mechanism found in conventional databases, the functional database uses data dependency to provide exclusion. Results obtained from a prototype database demonstrate that data dependency permits an unusual degree of concurrency between operations on the data. The prototype database is used to exhibit some problems that seriously restrict concurrency and also to demonstrate the resolution of these problems using a new primitive. The design of a more realistic database is outlined. Some restrictions on the data structures that can be used in a functional database are also uncovered. Manipulating databases. Functions over the database a...

We present a functional DBPL in the style of FP that facilitates the definition of precise semantics and opens up opportunities for far-reaching optimizations. The language is integrated into a functional data model, which is extended by arbitrary type hierarchies and complex objects. Thus we are able to provide the clarity of FP-like programs together with the full power of semantic data modelling. To give an impression of the special facilities for optimizing functional database languages, we point out some laws not presented before which enable access path selection already on the algebraic level of optimization. The algebraic way of access path optimization also gives new insights into optimization strategies. 1 Introduction The design of new database programming languages is still a challenging task, for on the one hand it has to meet the conceptual requirements of programming languages and database systems at the same time, and on the other hand it has to present a suita...

Problems with the inconsistent behaviour of system construction components for building large and long-lived application systems are identified. They make the programmer's task harder and the user's world more confusing in the same way that the disharmonies between programming languages and databases did. Persistent programming languages overcame those disharmonies. This paper challenges researchers to design and build a common substrate to the construction components. The construction components would be re-built using the substrate to achieve consistent behaviour. Application systems would then use this new family of construction components. The substrate, called the Scalable Persistent Foundation promises several advantages: consistent application system behaviour even when under stress, accelerated application system building and maintenance, genuine longevity of application systems and improved operational efficiency. The search for a design and implementation of this foundation w...

Practice has proven that databases are the keystones for nearly all application systems with a wider functionality, utilization and availabilty. As a consequence, next generation database systems will have to provide their services with a degree of interoperability that has to be substantially improved over existing solutions. In this paper we argue that this objective can be achieved only through full exploitation of current developments in computer language technology.