Papers by Harald Schöning
Realisierungskonzepte f�r die parallele Bearbeitung von Anfragen auf komplexen Objekten
Dagstuhl Seminars, 1990

Computer-Supported Cooperative Work' is a young research area considering applications with stron... more Computer-Supported Cooperative Work' is a young research area considering applications with strong demands on database technology. Especially design applications need support for cooperation and some means for controlling their inherent dynamics. However, today's CAD systems mostly consisting of a collection of diverse design tools typically do not support these requirements. Therefore, an encompassing processing model is needed that covers the overall design process in general as well as CAD-tool application in particular. As a consequence, this model has to be rich enough to reflect the major characteristics of design processes, e.g., goal-orientation, hierarchical refinement, stepwise improvement as well as team-orientation and cooperation. The CONCORD model that will be described in this paper, reflects the distinct properties of design process dynamics by distinguishing three levels of abstraction. The highest level supports application-specific cooperation control and design process administration, the second considers goal-oriented tool invocation and work-flow management while the third level provides tool processing of design data. To achieve level-spanning control, we rely on transactional facilities provided at the various system layers.

The molecule-atom data model allows the dynamic construction of complex objects using an identifi... more The molecule-atom data model allows the dynamic construction of complex objects using an identifier-reference concept. The model and its implementation in the PRIMA system are sketched. Then, with the help of some sample queries, some alternatives for query evaluation are discussed. The decision among the possible algorithms cannot be based on the standard statistics such as distribution of an attribute value. The kind of information needed is the correlation between graph properties and attribute values. In order to accelerate access, its components may be read in parallel. Using a maximum degree of parallelism for this purpose has disadvantages if the complex object does not qualify with respect to the condition included in the query. Criteria for an optimal degree of parallelism still have to be found. 1. To emphasize the single molecules, molecule overlapping is not shown graphically in Figure . However, some molecules do overlap (for instance, the molecules of type C-B-A share atom a 2 ).
Parallelism in Processing Queries on Complex Objects
Complex objects to support non-standard database applications require the use of substantial comp... more Complex objects to support non-standard database applications require the use of substantial computing resources because their powerful operations and their related integrity constraints must be performed and maintained in an interactive environment. Since the exploitation of parallelism within such operations seems to be promising, we investigate ):he principal approaches for processing a query on complex objects (molecules) in parallel. A
Tamino – A Database System Combining Text Retrieval and XML
Lecture Notes in Computer Science, 2003
In 1999, Software AG released the first version of its native XML server Tamino [276, 274, 275], ... more In 1999, Software AG released the first version of its native XML server Tamino [276, 274, 275], which includes a native XML database. The term native has become popular since then, being used with differing meanings. While some sources, e.g. [10], define a native XML database system only by its appearance to the user (“Defines a (logical) model for an XML document ... and stores and retrieves documents according to that model. ... For example, it can be built on a relational, hierarchical, or object-oriented database ...”), Software AG takes the definition further by requiring that a native XML database system has been built and designed for the handling of XML, and is not just a database system for an arbitrary data model with an XML layer on top.

Springer eBooks, 1989
Non-standard database applications require adequate modeling facilities for their application obj... more Non-standard database applications require adequate modeling facilities for their application objects which in general have an internal structure to be maintained by the database system. For this purpose, the database system has to provide fast access to such an object as a whole as well as to its components. In systems which support complex objects with a statically established structure, clustering of the objects' components along this structure is a widespread means to enhance efficiency. Systems which support the dynamic definition of complex objects' structures, however, cannot predict the characteristics of accesses to the database, and therefore have more problems in finding a storage structure that is useful for at least the majority of the accesses. In this paper, we propose a cluster mechanism that supports the flexibility and dynamism of the molecule-atom data model at the efficiency of static structure clustering. We discuss different alternatives for its design, taking into account the query processing strategies of the underlying database system. We address some problems concerning optimization that emerge from the dynamic structure definition and show some possible solutions.
Primary database system, replication database system and method for replicating data of a primary database system
Method for mass-deleting data records of a database system
Systems And/Or Methods for Introducing Semantic Concepts Into Complex Event Processing Environments
Signature validation and generation
Rekursion im MAD-Modell: Rekursivmolek�le als Objekte des Datenmodells
Btw, 1989
Database system, method and active repository
Systems and/or methods for appropriately handling events
Very Large Data Bases, Aug 24, 1998
The buffer pool manager is a central component of ADABAS, a high performance scaleable database s... more The buffer pool manager is a central component of ADABAS, a high performance scaleable database system for OLTP processing. High efficiency and scalability of the buffer pool manager is mandatory for ADABAS on all supported platforms. In order to allow a maximum of parallelism without facing the danger of deadlocks, a multi-version locking method is used. Partitioning of central data structures is another key to performance. Variable page sizes allow for flexible tuning, but make the buffer pool logic more sophisticated, in particular concerning parallelism.

International Conference on Data Engineering, Feb 14, 1994
Computer-Supported Cooperative Work' is a young research area considering applications with stron... more Computer-Supported Cooperative Work' is a young research area considering applications with strong demands on database technology. Especially design applications need support for cooperation and some means for controlling their inherent dynamics. However, today's CAD systems mostly consisting of a collection of diverse design tools typically do not support these requirements. Therefore, an encompassing processing model is needed that covers the overall design process in general as well as CAD-tool application in particular. As a consequence, this model has to be rich enough to reflect the major characteristics of design processes, e.g., goal-orientation, hierarchical refinement, stepwise improvement as well as team-orientation and cooperation. The CONCORD model that will be described in this paper, reflects the distinct properties of design process dynamics by distinguishing three levels of abstraction. The highest level supports application-specific cooperation control and design process administration, the second considers goal-oriented tool invocation and work-flow management while the third level provides tool processing of design data. To achieve level-spanning control, we rely on transactional facilities provided at the various system layers.
IEEE Data(base) Engineering Bulletin, 1989
Complex objects to support non-standard database applications require the use of substantial comp... more Complex objects to support non-standard database applications require the use of substantial computing resources because their powerful operations must be performed and maintained in an interactive environment. Since the exploitation of parallelism within such operations seems to be promising, we investigate the principal approaches for processing a query on complex objects (molecules) in parallel. A number of arguments favor methods based on inter-molecule parallelism as against intra-molecule parallelism. Retrieval of molecules may be optimized by multiple storage structures and access paths. Hence, maintenance of such storage redundancy seems to be another good application area to explore the use of parallelism.

New database applications, primarily in the areas of engineering and knowledge-based systems, ref... more New database applications, primarily in the areas of engineering and knowledge-based systems, refer to complex objects (e.g. representation of a CAD workpiece or a VLSI chip) while performing their tasks. Retrieval, maintenance, and integrity checking of such complex objects consume substantial computing resources which were traditionally used by conventional database management systems in a sequential manner. Rigid performance goals dictated by interactive use and design environments imply new approaches to master the functionality of complex objects under satisfactory time restrictions. Because of the object granularity, the set orientation of the database interface, and the complicated algorithms for object handling, the exploitation of parallelism within such operations seems to be promising. Our main goal is the investigation and evaluation of different hardware architectures and their suitability to efficiently cope with workloads generated by database operations on complex objects. Apparently, employing just a number of processors is not a panacea for our database problem. The sheer horse power of machines does not help very much when data synchronization and event serialization requirements play a major role during object handling. What are the critical hardware architecture properties? How can the existing MIPS be best utilized for the data management functions when processing complex objects? To answer these questions and related issues, we discuss different kinds of architectures combining multiple processors: loosely-, tightly-, and closely-coupled. Furthermore, we consider parallelism at different levels of abstraction: the distribution of (sub-)queries or the decomposition of such queries and their concurrent evaluation at an inter-or intra-object level. Finally, we give some thoughts as to the problems of load control and transaction management.

Very Large Data Bases, Sep 1, 1990
Support for temporal data continues to be a requirement posed by many applications. We show that ... more Support for temporal data continues to be a requirement posed by many applications. We show that a complex object data model is an appropriate means for handling temporal data. Firstly, we describe the main features of temporal databases in terms of time sequences, valid time, etc. We then explain the mapping of time sequences onto recursively structured complex objects. Operations on temporal data are easily transformed into complex object operations. To cope with the huge storage requirements arising from temporal databases, we integrate the concept of storing logical differences into our approach. Here, we exploit the extensibility of the underlying complex object's database system PRIMA. Finally, we briefly sketch a further improvement to guarantee fast access to the present data by storing them apart from the historical data without loosing the connection between both.

Support for temporal data continues to be a requirement posed by many applications such as VLSI d... more Support for temporal data continues to be a requirement posed by many applications such as VLSI design and CAD, but also in conventional applications like banking and sales. The strong demand for complex-object support is known as an inherent fact in design applications, but it also holds for advanced "conventional" applications. Thus, new advanced database management systems should include both features, i.e. should support temporal complex-objects. We show that such a system can be efficiently implemented on top of a (non-temporal) complex-object data model. The central notion of the temporal complex-object data model is a time slice, representing one state of a complex object. Time slices cannot be directly stored, if non-disjunct (i.e. overlapping) complex objects are allowed. We explain the mapping of time slices onto the complex objects supported by the MAD model. Operations on temporal complexobjects are easily transformed into MAD model operations. Furthermore, we reduce the huge storage requirements usually arising from temporal databases.
Datenplattformen, Datenräume und (Daten-)Ökosysteme – (IT) Architekturen und Praxis des Datenteilens
Springer eBooks, Dec 31, 2022
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Papers by Harald Schöning