Database and database technology are having a major impact on the growing use of computers. The rising popularity of database systems for the management of data has resulted in an increasing number of systems. As the number grows, the difficulty in choosing the system which will best meet the requirements of a particular application also increases. Knowing how to choose the correct one for a given application is important.The purpose of this thesis is to compare two very commonly used Database Management Systems (ORACLE and RDB) at Ball State University by describing and listing the advantages of each of them as well as their weaknesses, giving a comprehensive study of their performances, user friendliness, limits, and to aid users and managers in obtaining a deeper knowledge of these two systems. / Department of Computer Science

Databases and database technology are having a major impact on the growing use of computers. It is fair to say that databases are playing a critical role in almost all areas where computers are used, including business, engineering, medicine, law, education, and library science, to name a few.At Ball State University, databases are very widely used among faculty, staff, and students. The common commercial database management system (DBMS) used in the university is ORACLE. Due to the extensive use of the system and the availability and easy access to alternative systems such as RDB/VMS, a comparative research is in order.This thesis is a comprehensive comparison between the two systems. It covers the differences in design, SQL codings, and the use of host programming language such as FORTRAN. It concentrates on the differences in memory usage, execution time, as well as the CPU time needed to precompile, link, and run. / Department of Computer Science

Master of Science / Department of Computing and Information Sciences / Daniel A. Andresen / The recovery-driven design of the file system has been one of the most challenging fields over the major trends in operating systems. This field has assumed considerable importance in the past decades as the disk sizes have been increasing without a comparable increase in the disk I/O bandwidth and seek time. The rapid increase in the storage size is expected to become constant in the future due to the growing market demand and the continuous database size increment of many companies and major businesses. Due to the same reason, the cost of the average file system checking time has increased without a significant improvement in the disk I/O bandwidth and seek time performance. Operating system bugs, power outages, and hardware failures which result in a file system crash were the main reasons behind the innovation of novel recovery approaches such as Journaling and soft-updates. Although such approaches avoided complete file system checking by checking solely inconsistencies in file system metadata, it become inevitable for them to check the entire file system for inconsistencies because of the previously entioned types of problems. One of the emerging recovery-driven designs which considers minimizing file system checking cost is the Chunkfs files ystem. Chunkfs file system introduces an innovative look into the file system design by dividing the file system layout into smaller chunks, each one of which represents a smaller scale file system by itself. In our work we probed an alternative recovery-driven design which is considerably inspired by the Chunkfs concepts and follows the same design guidelines. This recovery-riven design is introduced by adding a new feature to the file system which best utilizes the existing underlying design through considering the block groups as individual chunks, confining their files and directories spanning across different block groups by means of special controlled continuation links. These links provide a fault isolation means by circumscribing the checking of the file system to only these block groups which appear to be dirty after a crash, a method resulting in a moderate reduction in file system checking cost. We also probed different metrics of metadata sizes, and the probable cost of files and directories expansion across the different block groups.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) to provide reliable delivery of files across space links. Space links are typically intermittent, requiring flexibility on the part of CFDP. Some aspects of that flexibility will be highlighted in this paper, which discusses the planned use of CFDP on the Global Precipitation Measurement (GPM) mission. The operational scenario for GPM involves reliable downlink of science data files at a high datarate (approximately 4 megabits per second) over a space link that is not only intermittent, but also one-way most of the time. This paper will describe how that scenario is easily handled by CFDP, despite the fact that reliable delivery requires a feedback loop.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Reliable delivery of data products is often required across space links. For example, a NASA mission will require reliable delivery of images produced by an on-board detector. Many missions have their own (unique) way of accomplishing this, requiring custom software. Many missions also require manual operations (e.g. the telemetry receiver software keeps track of what data is missing, and a person manually inputs the appropriate commands to request retransmissions). The Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) specifically for this situation. CFDP is an international standard communication protocol that provides reliable delivery of data products. It is designed for use across space links. It will work well if run over the widely used CCSDS Telemetry and Telecommand protocols. However, it can be run over any protocol, and will work well as long as the underlying protocol delivers a reasonable portion of the data. The CFDP receiver will autonomously determine what data is missing, and request retransmissions as needed. The CFDP sender will autonomously perform the requested transmissions. When the entire data product is delivered, the CFDP receiver will let the CFDP sender know that the transaction has completed successfully. The result is that custom software becomes standard, and manual operations become autonomous. This paper will consider various ways of achieving reliable file delivery, explain why CFDP is the optimal choice for use over space links, explain how the core protocol works, and give some guidance on how to best utilize CFDP within various mission scenarios. It will also touch on additional features of CFDP, as well as other uses for CFDP (e.g. the loading of on-board memory and tables).

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The MESSENGER mission to Mercury will downlink data files via a protocol defined by the Consultative Committee for Space Data Systems (CCSDS) called the CCSDS File Delivery Protocol (CFDP). A reduced implementation of the protocol was developed for the spacecraft due to various system constraints and operational requirements. The software operates in conjunction with the playback features of the MESSENGER flight software allowing for the autonomous downlinking of files as well as providing for the management of the file system by the mission operations team. This paper presents the software implementation, metrics, and the lessons learned.

Title: Analysis of a File System Using the Verifying C Compiler Author: Bc. David Škorvaga Department: Department of Distributed and Dependable Systems Supervisor: RNDr. Jan Kofroň, Ph.D. Abstract: Formal verification is a way to improve reliability of software systems. One approach of formal verification is focused on proving correctness of annotat- ed source code of an established programming language. Verifying C Compiler (VCC) is a verifier for concurrent C that accepts an annotated code in C language and automatically verifies its correctness with respect to the given annotation. There have been successful attempts to verify some critical systems, including the operating system kernel. Another critical part of operating system is its file system. In the thesis, we choose FatFs file system, a simple device-independent implementation of the FAT file system. We specify a part of it using the VCC annotation and successfully verify its correctness. Keywords: Formal Verification, File System, VCC

Boston University. University Professors Program Senior theses. / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-02

Conventional processor design utilizes a central register file and a bypass network to deliver operands to and from functional units, which cannot scale to a large number of functional units. As more functional units are integrated into a processor, the number of ports on a register file grows linearly while area, delay, and energy consumption grow even more rapidly. Physical properties of a bypass network scale in a similar manner. In this dissertation, a fully distributed register file organization is presented to overcome this limitation by relying on small register files with fewer ports and localized operand bypasses. Unlike other clustered microarchitectures, each cluster features a small single-issue functional unit coupled with a small local register file. Several clusters are used, and each of them can be different. All register files are connected through a register transfer network that supports multicast communications. Techniques to support distributed register file operations are presented for both dynamically and statically scheduled processors. These include the eager and multicast register transfer mechanisms in the dynamic approach and the global data routing with multicasting algorithm in the static approach. Although this organizaiton requires additional cycles to execute a program, it is compensated by significant savings obtained through smaller area, faster operand access time, and lower energy consumption. With faster operating frequency and more efficient hardware implementation, overall performance can be improved. Additionally, the fully distributed register file organization is applied to an ILP-SIMD processing element, which is the major building block of a massively parallel media processor array. The results show reduction in die area, which can be utilized to implement additional processing elements. Consequently, performance is improved through a higher degree of data parallelism through a larger processor array. In summary, the fully distributed register file architecture permits future processors to scale to a large number of functional units. This is especially desirable in high-throughput processors such as wide-issue processors and multithreaded processors. Moreover, localized communication is highly desirable in the transition to future deep submicron technologies since long wire is a critical issue in processes with extremely small feature sizes.

This dissertation presents novel approaches to the use of non-volatile memory devices in building storage systems. There are many types of non-volatile memory devices, and they usually have better performance than regular magnetic hard disks in terms of throughput and latency. This dissertation focused on two of them, NAND flash memory and Phase Change Memory (PCM). This work consisted of two parts. The first part was to design a high-performance hybrid storage system employing Solid State Drives that are build out of NAND flash memory and Hard Disk Drives. In this hybrid system, we proposed two different policies to improve its performance. One is to exploit the fact that the performances of Solid State Drive and Hard Disk Drive are asymmetric and the other is to exploit concurrency on multiple devices. We implemented prototypes in Linux and evaluate both policies in multiple workloads and multiple configurations. The results showed that the proposed approaches improve the performance significantly, and adapt to different configurations of the system under different workloads. The second part was to implement a file system on a special class of memory devices, Storage Class Memory (SCM), which is both byte addressable and also nonvolatile, e.g. PCM. We claimed that both the existing regular file systems and the memory based file systems are not suitable for SCM, and proposed a new file system, called SCMFS, which is implemented on the virtual address space. In SCMFS, we utilized the existing memory management module in the operating system to do the block management. Our design keeps address space within a file contiguous to reduce the block management software. The simplicity of SCMFS not only makes it easy to implement, but also improves the performance. We implemented a prototype of SCMFS in Linux and evaluated its performance through multiple benchmarks.