An orthogonally persistent Java

Abstract

The language Java is enjoying a rapid rise in popularity as an application programming language. For many applications an effective provision of database facilities is required. Here we report on a particular approach to providing such facilities, called "orthogonal persistence". Persistence allows data to have lifetimes that vary from transient to (the best approximation we can achieve to) indefinite. It is orthogonal persistence if the available lifetimes are the same for all kinds of data. We aim to show that the programmer productivity gains and possible performance gains make orthogonal persistence a valuable augmentation of Java.

AOP: Does It Make Sense? The Case of Concurrency and Failures

“…Argus [25], Arjuna [26], KAROS [27], Transactional Drago [28] or PJama [29,30,18], provide primitives for expressing transaction boundaries within methods, and not as separate concerns. Furthermore, even if the systems underlying those languages provide default mechanisms for handling concurrency and failures, most work on how to obtain effective mechanisms advocate the tight integration of the mechanisms within the actual methods or objects [21,31,32].…”

Automatic Prefetching by Traversal Profiling in Object Persistence Architectures

“…Examples of object persistence architectures include object-relational mapping tools [10,6,28,24], object-oriented databases [8,21], and orthogonally persistent programming languages [25,2,19,22].…”

“…In particular, any object can be persistent, whether an object is persistent does not affect its other behaviors, and an object is persistent if it is reachable from a persistent root. Orthogonal persistence has been implemented, to a degree, in a variety of programming languages [25,2,19,22].…”

Object-oriented Access Control in Jarrah.

“…Unlike the light-weight persistence of Java, Jarrah supports persistent objects which can be concurrently shared by multiple processes and which need not be explicitly stored and loaded. These aims are similar to those of PJama [1] and database-based approaches such as JDBC [11]. Jarrah differs in that it focuses on security, allows multiple realisations of persistence within a single application and supports distributed object systems.…”

“…Examples are systems such as PJama [1] and PerDiS [9] which provide a special persistent object store to manage persistence transparently according to this principle. This approach has a number of problems in terms of information security and access control since a piece of data cannot be considered to be 'held inside' a persistent container object as is the case with Jarrah.…”