Robert Marek

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Parallel database systems have to support both inter-transaction as well as intra-transaction parallelism. Inter-transaction parallelism (multi-user mode) is required to achieve high throughput, in particular for OLTP transactions, and sufficient cost-effectiveness. Intra-transaction parallelism is a prerequisite for reducing the response time of complex(More)
Zunehmend komplexe und datenintensive Benutzeranfragen auf Datenbanken verlangen parallele Verarbeitungsansätze. Vor allem Datenbanksysteme der Architekturklasse Shared-Nothing bieten derzeit eine geeignete Basis für die parallele Anfragebearbeitung. Im Hinblick auf den interaktiven Charakter komplexer Datenbankanfragen ist eine Verkürzung der Antwortzeit(More)
TID hash joins are a simple and memory-efficient method for processing large join queries. They are based on standard hash join algorithms but only store TID/key pairs in the hash table instead of entire ttrples. This typically reduces memory requirements by more than art order of magnitude bringing substantial benefits. In particular, performance for joins(More)
Complex and data-intensive database queries mandate parallel processing strategies to achieve sufficiently short response times. In praxis, parallel database processing is mostly based on so-called "shared nothing" architectures entailing a physical partitioning and allocation of the database among multiple processing nodes. We examine the performance of(More)
Parallel database systems aim at providing high throughput for OLTP transactions as well as short response times for complex and data-intensive queries. Shared nothing systems represent the major architecture for parallel database processing. While the performance of such systems has been extensively analyzed in the past, the corresponding studies have made(More)
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