We present a domain-independent model of hierarchical software system design and construction that is based on interchangeable software components and largescale reuse. The model unifies the conceptualizations of two independent projects, Genesis and Avoca, that are successful examples of software component/building-block technologies and domain modeling. Building-block technologies exploit large-scale reuse, rely on open architecture software, and elevate the granularity of programming to the subsystem level. Domain modeling formalizes the similarities and differences among systems of a domain. We believe our model is a blue-print for achieving software component technologies in many domains.

Consider a database containing not only base relations but also stored derived relations (also called materialized or concrete views). When a base relation is updated, it may also be necessary to update some of the derived relations. This paper gives sufficient and necessary conditions for detecting when an update of a base relation cannot affect a derived relation (an irrelevant update), and for detecting when a derived relation can be correctly updated using no data other than the derived relation itself and the given update operation (an autonomously computable update). The class of derived relations considered is restricted to those defined by PSJ-expressions, that is, any relational algebra expression constructed from an arbitrary number of project, select and join operations (but containing no self-joins). The class of update operations consists of insertions, deletions, and modifications, where the set of tuples to be deleted or modified is specified by a selection condition on ...

GenVoca generators synthesize software systems by composing components from reuse libraries. Although GenVoca components can be composed in a vast number of ways, not all compositions are correct. In this paper, we present a model for validating component compositions. The model is based on attribute grammars and provides a powerful debugging capability of explanation-based error reporting. We demonstrate our results with examples from a GenVoca generator for container data structures. Keywords: software architectures, software system generators, attribute grammars, domain models, GenVoca, software components, explanation-based error reporting. 1 Introduction Software component technologies will play an important role in future software development. Examples of today's componentry include Unix file filters and Visual Basic custom controls (VBXes) [Ude94]. Support for componentry in distributed environments is under development: the Object Management Group's CORBA (Common Object Reque...

The generalized search tree, or GiST, defines a framework of basic interfaces required to construct a hierarchical access method for database systems. As originally specified, GiST only supports record selection. We show how a small number of additional interfaces enable GiST to support a much larger class of operations. Members of this class, which includes, nearest-neighbor and ranked search, user-defined aggregation and index-assisted selectivity estimation, are increasingly common in new database applications. The advantages of implementing these operations in the GiST framework include reduction of user development effort and the ability to use industrial strength concurrency and recovery mechanisms provided by expert implementers

We present a model of the data structure domain that is expressed in terms of the GenVoca domain modeling concepts [Bat91]. We show how familiar data structures can be encapsulated as realms of plug-compatible, symmetric, and reusable components, and we show how complex data structures can be formed from their composition. The target application of our research is a precompiler for specifying and generating customized data structures.

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Scientists’ ability to generate and store simulation results is outpacing their ability to analyze them via ad hoc programs. We observe that these programs exhibit an algebraic structure that can be used to facilitate reasoning and improve performance. In this dissertation, we present a formal data model that exposes this algebraic structure, then implement the model, evaluate it, and use it to express, optimize, and reason about data transformations in a variety of scientific domains. Simulation results are defined over a logical grid structure that allows a con-tinuous domain to be represented discretely in the computer. Existing approaches for manipulating these gridded datasets are incomplete. The performance of SQL queries that manipulate large numeric datasets is not competitive with that of specialized tools, and the up-front effort required to deploy a relational database makes them unpopular for dynamic scientific applications. Tools for processing multidimensional arrays can only capture regular, rectilinear grids. Visualization libraries accommodate arbitrary grids, but no algebra has been developed to simplify their use and afford optimization. Further, these libraries are data dependent—physical

Recent excitement in the database community surrounding new applications—analytic, scientific, graph, geospatial, etc.—has led to an explosion in research on database storage systems. New storage systems are vital to the database community, as they are at the heart of making database systems perform well in new application domains. Unfortunately, each such system also represents a substantial engineering effort including a great deal of duplication of mechanisms for features such as transactions and caching. In this paper, we make the case for RodentStore, an adaptive and declarative storage system providing a high-level interface for describing the physical representation of data. Specifically, RodentStore uses a declarative storage algebra whereby administrators (or database design tools) specify how a logical schema should be grouped into collections of rows, columns, and/or arrays, and the order in which those groups should be laid out on disk. We describe the key operators and types of our algebra, outline the general architecture of RodentStore, which interprets algebraic expressions to generate a physical representation of the data, and describe the interface between RodentStore and other parts of a database system, such as the query optimizer and executor. We provide a case study of the potential use of RodentStore in representing dense geospatial data collected from a mobile sensor network, showing the ease with which different storage layouts can be expressed using some of our algebraic constructs and the potential performance gains that a RodentStore-built storage system can offer.

The unbundling of components from a (monolithic) database management system is an upcoming research topic. In this paper we describe the origin of unbundling techniques: unbundling in operating systems like SunOS 5.x and construction of a component-oriented database system like Open OODB from Texas Instruments, Inc. by using the EXODUS toolkit. Afterwards we discuss the commercial OODBMS ObjectStore to identify unbundling issues. In the core part we present the active database systems REACH and SAMOS from an unbundling point of view. Finally we introduce an objectoriented mediator for relational legacy systems and show that such a component also can be seen as unbundled. Keywords: unbundling, architecture, components. 1 Introduction Unbundling is an upcoming buzzword in the database community. However, it is not clear what does it mean when a component is declared as unbundled, how can components be identified for unbundling, and how should components be designed to make them unbundl...