With the emergence of new hardware technologies, new opportunities arise and existing database architectures have to be rethought to fully exploit them. In particular, recovery mechanisms of current main-memory database systems are tuned to efficiently work on block-oriented, high-latency storage devices. These devices create a bottleneck during transaction processing. In this paper, we investi...

Parallelizing multidimensional indexes for main memory databases Master thesis,

A novel memory subsystem called Memory Expansion Technology (MXT) has been built for compressing main memory contents. This allows effectively a memory expansion that presents a “real” memory larger than the physically available memory. This paper provides an overview of the architecture and OS support and in-depth analysis of the performance impact of memory compression using the SPEC2000 benc...

BitMat is a main memory based bit-matrix structure for representing a large set of RDF triples, designed primarily to allow processing of conjunctive triple pattern (join) queries. The key aspects are as follows: i) its RDF triple-set representation is compact compared to conventional disk-based and existing main-memory RDF stores, ii) basic join query processing employs logical bitwise AND/OR ...

The availability of powerful servers with terabytes of main-memory has sparked a renewed interest in main-memory database systems. Many early proposals focus on a single workload type, either short transactions or long-running, read-only analytical queries. In this thesis, we focus on allowing a broad range of workloads to be executed concurrently on the same state of the data. While concurrenc...

In the last years, the deployment of embedded real-time communication systems has increased dramatically. At the same time, the amount of data that needs to be managed by embedded real-time main memory databases is increasing, thus requiring an efficient data management. However, system crash will cause data loss in main memory, which will seriously affect the normal operation of the entire com...

Memory resident database systems (MMDB’s) store their data in main physical memory and provide very high-speed access. Conventional database systems are optimized for the particular characteristics of disk storage mechanisms. Memory resident systems, on the other hand, use different optimizations to structure and organize data, as well as to make it reliable. This paper surveys the major memory...

A recent PVLDB paper reports on experimental analyses of ten spatial join techniques in main memory. We build on this comprehensive study to raise awareness of the fact that empirical running time performance findings in main-memory settings are results of not only the algorithms and data structures employed, but also their implementation, which complicates the interpretation of the results. In...

An increasing number of applications depend on efficient storage and analysis features for XML data. Hence, query optimization and efficient evaluation techniques for the emerging XQuery standard become more and more important. Many XQuery queries require nested expressions. Unnesting them often introduces binary grouping. We introduce several algorithms implementing binary grouping and analyze...

eScience and big data analytics applications are facing the challenge of efficiently evaluating complex queries over vast amounts of structured text data archived in network storage solutions. To analyze such data in traditional disk-based database systems, it needs to be bulk loaded, an operation whose performance largely depends on the wire speed of the data source and the speed of the data s...