Rinda: a relational database processor with hardware specializedfor searching and sorting

Rinda, a database processor that accelerates nonindexed relational database queries, is described. Rinda is composed of content search processors and relational operational accelerating processors; the former, search rows stored in disk storage, and the latter sort rows stored in the main memory. The processors connect to a general-purpose host computer with channel interfaces. Performance results show that Rinda executes queries three to 100 times faster then conventional database-management system software in a benchmark system     

A group-select operation for relational algebra and implicationsfor database machine design

A group-select operation has been defined for relational algebra. This operation is found to be useful for efficiently reducing expressions of nonprocedural relational languages that permit natural quantifiers. Conceptually, the operation first partitions a relation into blocks of tuples that have the same value for an attribute or attribute concatenation. It then extracts each block for which a specified number of tuples meet a specified condition. The quantity of tuples for the operation is specified by means of a natural quantifier. Performance of the group-select operation will be poor with conventional file processing, making the operation more suitable for use with a database machine with an associative memory     

A functional processor for the relational algebra on a microcomputer

We have built on the U.C.S.D. P-system (running on an IBM Personal Computer) a relational algebra processor, MRDS/FS, which is extremely powerful and which supports a functional syntax for the programmer-user. The relational algebra is provided in the extended operators μ-join, σ-join, project and select. The domain algebra is fully implemented for the first time, giving operations on attributes: arithmetic, logic, comparison and four different categories of aggregation of these. A strictly functional syntax is provided, permitting user-defined functions using the relational and domain algebras as primitive operations. An interactive editor permits the creation, copying and changing of both relations and user-defined functions.     

A suggestion for performance improvement in a relational database machine

Database machines are special purpose backend architectures that are designed to support efficiently database management system operations. An important problem in the development of database machines has been that of increasing their performance. Earlier research on the performance evaluation of database machines has indicated that I/O operations constitute a principle performance bottleneck. This is increasingly the case with the advances in multiprocessing and a growth in the volume of data handled by a database machine. One possible strategy to improve the performance of such a system which handles huge volumes of data is to store the data in a compressed form. This can be achieved by introducing VLSI chips for data compression so that data can be compressed and decompressed “on-the-fly”. A set of hardware algorithms for data compression based on the Huffman coding scheme proposed in an earlier work is described. The main focus of this paper is the investigation conducted by the authors to study the effect of incorporating such hardware in a special purpose backend relational database machine. Detailed analytical models of a relational database machine and the analytical results that quantify the performance improvement due to compression hardware are presented.     

A complete temporal relational algebra

Various temporal extensions to the relational model have been proposed. All of these, however, deviate significantly from the original relational model. This paper presents a temporal extension of the relational algebra that is not significantly different from the original relational model, yet is at least as expressive as any of the previous approaches. This algebra employs multidimensional tuple time-stamping to capture the complete temporal behavior of data. The basic relational operations are redefined as consistent extensions of the existing operations in a manner that preserves the basic algebraic equivalences of the snapshot (i.e., conventional static) algebra. A new operation, namely temporal projection, is introduced. The complete update semantics are formally specified and aggregate functions are defined. The algebra is closed, and reduces to the snapshot algebra. It is also shown to be at least as expressive as the calculus-based temporal query language TQuel. In order to assess the algebra, it is evaluated using a set of twenty-six criteria proposed in the literature, and compared to existing temporal relational algebras. The proposed algebra appears to satisfy more criteria than any other existing algebra. Edited by Wesley Chu. Received February 1993 / Accepted April 1995     

一种新的关系数据库水印算法研究

针对现有水印算法的不足,提出了一种新的关系数据库水印算法.算法首先筛选出可以嵌入水印信息的属性并将他们划分为若干个等大的子集,然后将水印信息的每个二进制位嵌入到相应的子集中.水印检测依据的是中心极限定理,并且实现了水印信息的准确检测.最后通过SQL server进行仿真实验,验证此方法在现实应用中的有效性.     

Generalizing database relational algebra for the treatment of incomplete or uncertain information and vague queries

This paper deals with relational databases which are extended in the sense that fuzzily known values are allowed for attributes. Precise as well as partial (imprecise, uncertain) knowledge concerning the value of the attributes are represented by means of [0,1]-valued possibility distributions in Zadeh's sense. Thus, we have to manipulate ordinary relations on Cartesian products of sets of fuzzy subsets rather than fuzzy relations. Besides, vague queries whose contents are also represented by possibility distributions can be taken into account. The basic operations of relational algebra, union, intersection, Cartesian product, projection, and selection are extended in order to deal with partial information and vague queries. Approximate equalities and inequalities modeled by fuzzy relations can also be taken into account in the selection operation. Then, the main features of a query language based on the extended relational algebra are presented. An illustrative example is provided. This approach, which enables a very general treatment of relational databases with fuzzy attribute values, makes an extensive use of dual possibility and necessity measures.     

A parallel algorithm for relational database normalization

The problem of database normalization in a parallel environment is examined. Generating relation schemes in third normal form is straightforward when given a set of functional dependencies that is a reduced cover. It is shown that a reduced cover for a set of functional dependencies can be produced in parallel. The correctness of the algorithm is based on two important theorems. it is demonstrated that the companion third normal form algorithm can be easily translated into a parallel version. The performance of the two algorithms is compared to the performance of their serial counterparts. The standard serial algorithms for computing minimal covers and synthesizing third normal form relations are presented. The parallel algorithms and their rationale are discussed     

A relational database system for student use

An APL implementation of a relational database system suitable for small interactive databases in a teaching environment is described Both user and database administrator functions are implemented. The system has a command-driven user-friendly interface.     

A fine-grain architecture for relational database aggregationoperations

The design and simulation of a bit-sliced processor for relational database aggregation functions, are discussed. The processor, which addresses an important, computationally expensive problem in database computers, takes two tuples as input (one bit at a time) and returns two bits as output every clock cycle. A larger aggregation unit uses a number of identical slice processors, connected according to odd-even network topology, to achieve improved performance on a parallel pipelined processor. The data processing time is completely overlapped with the input and output of data to and from the unit. The design is independent of the tuple size, and since a bit-serial computation is used, the system requires limited interconnection     

A 1NF temporal relational model and algebra coping with valid-time temporal indeterminacy

In the real world, many phenomena are time related and in the last three decades the database community has devoted much work in dealing with “time of facts” in databases. While many approaches incorporating time in the relational model have been already devised, most of them assume that the exact time of facts is known. However, this assumption does not hold in many practical domains, in which temporal indeterminacy of facts occurs. The treatment of valid-time indeterminacy requires in-depth extensions to the current relational approaches. In this paper, we propose a theoretically grounded approach to cope with this issue, overcoming the limitations of related approaches in the literature. In particular, we present a 1NF temporal relational model and propose a new temporal relational algebra to query it. We also formally study the properties of the new data model and algebra, thus granting that our approach is interoperable with pre-existent temporal and non-temporal relational approaches, and is implementable on top of them. Finally, we consider computational complexity, showing that only a limited overhead is added when moving from determinate to indeterminate time.     

使用ADO实现关系数据库访问层

在使用面向对象方法开发关系数据库应用系统时,人们希望对业务逻辑层开发人员隐藏在关系数据库中存取对象的细节,数据库访问层模式就是解决这个问题的一种设计模式。数据库访问层可以以多种方式实现,以ADO数据访问技术为基础,描述了一个关系数据库访问层的实现方案。     

A relational tsetlin machine with applications to natural language understanding

Journal of Intelligent Information Systems - Tsetlin machines (TMs) are a pattern recognition approach that uses finite state machines for learning and propositional logic to represent patterns. In...     

RDBM—A relational data base machine

After a short introduction to the field of data base machines the design of the RDBM (Relational Data Base Machine) is presented, which provides all the functions required of a relational data base system. Frequently used and time-consuming functions are supported by appropriate hardware components. A transaction-oriented multi-user system was designed which exploits the inherent parallelism of user tasks and data base functions.The RDBM consists of a quasi-associative mass store together with a system of special function processors with common access to a large main memory, and a general purpose mini-computer exercising overall control over all hardware components.     

GRDB: A general purpose relational database system

This article discusses the design and development of GRDB (General Purpose Relational Data Base System) which has been implemented on a DEC-1090 system in Pascal. GRDB is a general purpose database system designed to be completely independent of the nature of data to be handled, since it is not tailored to the specific requirements of any particular enterprise. It can handle different types of data such as variable length records and textual data. Apart from the usual database facilities such as data definition and data manipulation, GRDB supports User Definition Language (UDL) and Security definition language. These facilities are provided through a SEQUEL-like General Purpose Query Language (GQL). GRDB provides adequate protection facilities up to the relation level. The concept of “security matrix” has been made use of to provide database protection. The concept of Unique IDentification number (UID) and Password is made use of to ensure user identification and authentication. The concept of static integrity constraints has been used to ensure data integrity. Considerable efforts have been made to improve the response time through indexing on the data files and query optimisation. GRDB is designed for an interactive use but alternate provision has been made for its use through batch mode also. A typical Air Force application (consisting of data about personnel, inventory control, and maintenance planning) has been used to test GRDB and it has been found to perform satisfactorily.     

类-关系数据库之间的映射

面向对象的开发方法是目前软件开发的主要方法,它以类作为软件分析,设计和实现的基本单元,而关系数据库则是许多人都青睐的持久信息存储方法,所以类－－关系数据库之间的映射是开发者必须关注的一件大事,文章扼要地介绍了类－－关系数据库之间的映射原则。     

A multipurpose neural processor for machine vision systems

A multitask neural network is proposed as a plausible visual information processor for performing a variety of real-time operations associated with the early stages of vision. The computational role performed by the processor, named the positive-negative (PN) neural processor, emulates the spatiotemporal information processing capabilities of certain neural activity fields found along the human visual pathway. The state-space model of this visual information processor corresponds to a bilayered two-dimensional array of densely interconnected nonlinear processing elements (PE's). An individual PE represents the neural activity exhibited by a spatially localized subpopulation of excitatory or inhibitory nerve cells. Each PE may receive inputs from an external signal space as well as from itself and the neighboring PE's within the network. The information embedded in the external input data which originates from a video camera or another processor is extracted by the feedforward subnet. The feedback subnet of the PN neural processor generates a variety of transient and steady-state activities. Their various computational roles are applicable to gray level, edge, texture, or color information processing. Computer simulations involving gray level image processing are used to illustrate the versatility of the PN neural processor architecture for machine vision system design.     

A dynamic associative processor for machine vision applications

The use of massively parallel associative processors as coprocessors for accelerating machine vision applications is considered. They achieve very fine granularity, as every word of memory functions as a simple processing element. A dense, dynamic, content-addressable memory cell supports fully parallel operation, and pitch-matched word logic improves arithmetic performance with minimal area cost. An asynchronous reconfigurable mesh network handles interprocessor communication and image input/output, and an area-efficient pass-transistor circuit counts and prioritizes responders. Some applications are discussed