Stefanie Scherzinger

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In this demonstration, we present the main-memory based streaming XQuery engine GCX which implements novel buffer management strategies that combine static and dynamic analysis to keep main memory consumption low. Depending on the progress made in query evaluation, memory buffers are dynamically purged and minimized. In this demo, we show the various stages(More)
We introduce an extension of the XQuery language , FluX, that supports event-based query processing and the conscious handling of main memory buffers. Purely event-based queries of this language can be executed on streaming XML data in a very direct way. We then develop an algorithm that allows to efficiently rewrite XQueries into the event-based FluX(More)
We introduce the notion of XML Stream Attribute Grammars (XSAGs). XSAGs are the first scalable query language for XML streams (running strictly in linear time with bounded memory consumption independent of the size of the stream) that allows for actual data transformations rather than just document filtering. XSAGs are also relatively easy to use for(More)
Acknowledgements My special thanks go to professor Christoph Koch and Stefanie Scherzinger. In particular, I want to thank professor Christoph Koch for having chosed the exciting topic, for excellent supervision, many discussions and all the time he spent in supporting my diploma thesis. Stefanie Scherzinger contributed to this thesis with many valuable(More)
NoSQL data stores are commonly schema-less, providing no means for globally defining or managing the schema. While this offers great flexibility in early stages of application development, developers soon can experience the heavy burden of dealing with increasingly heterogeneous data. This paper targets schema evolution for NoSQL data stores, the complex(More)
NoSQL data stores are becoming increasingly popular in application development. These systems are attractive for developers due to their ability to handle large volumes of data, as well as data with a high degree of structural variety. Typically , NoSQL data stores are accessed programmatically. Due to the imminent lack of standardized query languages,(More)
— We propose a new technique for the efficient search and navigation in XML documents and streams. This technique takes string matching algorithms designed for efficient keyword search in flat strings into the second dimension, to navigate in tree structured data. We consider the important XML data management task of prefiltering XML documents (also called(More)