Database computing in HEP

The major SSC experiments are expected to produce up to 1 Petabyte of data per year each. Once the primary reconstruction is completed by farms of inexpensive processors, I/O becomes a major factor in further analysis of the data. We believe that the application of database techniques can significantly reduce the I/O performed in these analyses. We present examples of such I/O reductions in prototypes based on relational and object-oriented databases of CDF data samples

Database computing in HEP. Progress report

The major SSC experiments are expected to produce up to 1 Petabyte of data per year each. Once the primary reconstruction is completed by farms of inexpensive processors. I/O becomes a major factor in further analysis of the data. We believe that the application of database techniques can significantly reduce the I/O performed in these analyses. We present examples of such I/O reductions in prototype based on relational and object-oriented databases of CDF data samples

Requirements for a system to analyze HEP events using database computing

We describe the requirements for the design and prototyping of an object-oriented database designed to analyze data in high energy physics. Our goal is to satisfy the data processing and analysis needs of a generic high energy physics experiment to be proposed for the Superconducting SuperCollider (SSC), and requires the collection and analysis of between 10 and 100 million sets of vectors (events), each approximately one megabyte in length. We sketch how this analysis would proceed using an object-oriented database which support the basic data types used in HEP

Sonochemische Transformation von sauerstoffhaltigen Kraftstoffadditiven unter aquatischen Bedingungen

In dieser Arbeit soll die Moeglichkeit des Einsatzes von Ultraschall beim Abbau von MTBE in Wasser, der so genannten Aquasonolyse, untersucht werden. Es soll aufgezeigt werden, welche verschiedenen Bedingungen Einfluss auf die Aquasonolyse haben. Dazu zaehlen einerseits geraetespezifische Einfluesse, z.B. die Frequenz und die Leistung des Ultraschalls und andererseits substanzspezifische Einfluesse, z.B. die Konzentration. Das Ziel ist, Grundlagen fuer eine effektive Reinigung von MTBE-kontaminiertem Wasser durch den Einsatz von Ultraschall zu erarbeiten. (orig.)The purpose of the present study was to examine the possibility of decomposing MTBE by means of aquasonolysis, i.e. the application of ultrasound in water. This required identifying the various influences on aquasonolysis, including device-specific influences such as ultrasound frequency and power output as well as substance-specific influences such as concentration. The ultimate goal was to create a knowledge base for the effective purification of MTBE-contaminated water by means of ultrasound.SIGLEAvailable from: http://www.db-thueringen.de/dissOnline / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

The Impact of More Accurate Requested Runtimes on Production Job Scheduling Performance

Abstract. The question of whether more accurate requested runtimes can significantly improve production parallel system performance has previously been studied for the FCFS-backfill scheduler, using a limited set of system performance measures. This paper examines the question for higher performance backfill policies, heavier system loads as are observed in current leading edge production systems such as the large Origin 2000 system at NCSA, and a broader range of system performance measures. The new results show that more accurate requested runtimes can improve system performance much more significantly than suggested in previous results. For example, average slowdown decreases by a factor of two to six, depending on system load and the fraction of jobs that have the more accurate requests. The new results also show that (a) nearly all of the performance improvement is realized even if the more accurate runtime requests are a factor of two higher than the actual runtimes, (b) most of the performance improvement is achieved when test runs are used to obtain more accurate runtime requests, and (c) in systems where only a fraction (e.g., 60%) of the jobs provide approximately accurate runtime requests, the users that provide the approximately accurate requests achieve even greater improvements in performance, such as an order of magnitude improvement in average slowdown for jobs that have runtime up to fifty hours.