In this work, techniques for efficient operation execution on multidimensional arrays in database management systems are developed. All the techniques described here are implemented in the RasDaMan system, which provides a declarative query language on multidimensional arrays. The operations specified in this query language are executed using the operation execution engine developed here. Arrays of arbitrary base type, including user defined structures, are supported. This implies the use of a dynamic type system supporting definition of types at runtime of the server. The data can be of arbitrary dimensionality and size. Operation execution must be flexible enough to cope with this data. At the same time, efficiency is a key target, as the data volumes operated on are typically very big. Tiles are the basic unit of physical data storage for multidimensional arrays in the RasDaMan DBMS. All operations specified on arrays in queries are finally executed on tiles, so they form the basis for operation execution. A formalism defining semantics of operations on multidimensional tiles is developed. This formalism takes the basic properties of tiles into account: base type and spatial domain. Semantics of operations and the applicability of operations are defined on these properties. Based on the formalism, the design for an operation execution engine for multidimensional arrays is developed. This design has two major goals: Encapsulation of the actual implementation to present a clear interface to other modules of the system and efficiency when executing operations. An object-oriented model is developed to provide for encapsulation. This model provides efficiency by avoiding multiple iterations through cells when possible. Furthermore, the encapsulation enables the optimisation of algorithms for operation execution without affecting other modules. The efficiency of this implementation is evaluated using workloads from common application fields. A thorough performance analysis of the implemented code is carried out based on an instrumentation of the system. Operation execution is proven to be a key component in efficient query execution. A performance comparison with the current state of the art in data base technology is done.
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In this work, techniques for efficient operation execution on multidimensional arrays in database management systems are developed. All the techniques described here are implemented in the RasDaMan system, which provides a declarative query language on multidimensional arrays. The operations specified in this query language are executed using the operation execution engine developed here. Arrays of arbitrary base type, including user defined structures, are supported. This implies the use of a d...
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