Duration

2003

Description

We continuously performed research on different aspects of Parallel database systems (PDBS) between 1985 and 2001. Early work focused on concurrency and coherency control in Shared-Disk DBMS and closely coupled SD systems.

We then investigated various kinds of dynamic load balancing for multi-user query workloads. For dynamic load balancing we also considered Shared Nothing and a dynamic redistribution of data, particularly for parallel join processing. Here we developed new algorithms for dynamically determining the number of join queries and for their processor allocation (VLDB93, VLDB95). These decisions are made dependent on the current utilization of multiple resources, in particular, CPU and memory/disk. Performance evaluations were mostly done by simulations (partly trace-driven).

Lastly, within a DFG project (1997-2001) we also considered data allocation especially for SD-based data warehouses. A new data allocation tool, Warlock (Warehouse allocation to disk) was developed and demoed at VLDB 2001 in Rome, Italy (poster, demo).

 

Publikationen (32)

Dateien Cover Beschreibung Jahr
Dynamic Load Balancing in Parallel Database Systems
Rahm, E.
Proc. EURO-PAR 96 Conf, LNCS 1123, Springer-Verlag, Lyon, Aug. 1996 (Keynote Paper)
1996
Dynamic Multi-Resource Load Balancing in Parallel Database Systems
Rahm, E. ; Marek, R.
Proc. 21th Int. Conf. on Very Large Database Systems, Zurich, Sep. 1995
1995
Analysis of Parallel Scan Processing in Shared Disk Database Systems
Rahm, E. ; Stöhr, T.
Proc. EURO-PAR, Stockholm, Springer-Verlag, LNCS, Aug. 1995
1995
Mehrrechner-Datenbanksysteme
Rahm, E.
Addison-Wesley-Verlag
1994
Hochleistungs-Transaktionssysteme
Rahm, E.
Vieweg-Verlag Braunschweig/Wiesbaden
1993
Parallel Query Processing in Shared Disk Database Systems
Rahm, E.
Sigmod Record, 22(4): 32-37, Dec. 1993. <a href=\"file/SD-HPTS-1993.pdf \">Long version</a> from:Proc. 5th Int. Workshop on High Performance Transaction Systems, Asilomar (CA), USA, Sep. 1993;
1993
Analysis of Dynamic Load Balancing Strategies for Parallel Shared Nothing Database Systems
Rahm, E. ; Marek, R.
Proc. 19th Int. Conf. on Very Large Database Systems, Dublin, August 1993, pp. 182-193
1993
Empirical Performance Evaluation of Concurrency and Coherency Control Protocols for Database Sharing Systems
Rahm, E.
ACM Transactions on Database Systems, Vol. 18, No. 2, June 1993, pp. 333-377.
1993
On the Performance of Parallel Join Processing in Shared Nothing Database Systems
Marek, R. ; Rahm, E.
Proc. 5th Int. PARLE Conf. (Parallel Architectures and Languages Europe), Springer Lecture Notes in Computer Science 694, pp. 622-633
1993
Evaluation of Closely Coupled Systems for High Performance Database Processing
Rahm, E.
Proc. 13th Int. Conf. on Distributed Computing Systems, Pittsburgh, USA, May 1993, IEEE Computer Society Press, pp. 301-310
1993