The process of validating the internal functionality of a query optimizer includes the selection of appropriate queries to be used as test cases for exercising and validating specific code paths. Specifically, it is d...
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ISBN:
(纸本)9781605582337
The process of validating the internal functionality of a query optimizer includes the selection of appropriate queries to be used as test cases for exercising and validating specific code paths. Specifically, it is desirable to be able to implement unit-tests for small components of the query optimizer such as the query transformation rules. In this paper, we present a practical method that simplifies the creation of test cases for validating query transformation rules in a query optimizer. We present the QRel programming framework, which allows designing test cases based on relational algebra expressions. We show how such a framework can be used to create classes of similar test cases that exercise transformation rules over a variety of relational algebra expressions. Finally, we provide some examples of how QRel is used to validate sqlserver's optimizations for subqueries. Copyright 2008 ACM.
When considering the past or the future, dear apprentice, be mindful of the present. If, while considering the past, you become caught in the past, lost in the past, or enslaved by the past, then you have forgotten yo...
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When considering the past or the future, dear apprentice, be mindful of the present. If, while considering the past, you become caught in the past, lost in the past, or enslaved by the past, then you have forgotten yourself in the present. If, while considering the future, you become caught in the future, lost in the future, or enslaved by the future, then you have forgotten yourself in the present. Conversely, when considering the past, if you do not become caught, lost, or enslaved by the past, then you have remained mindful of the present. And if, when considering the future, you do not become caught, lost, or enslaved in the future, then you have remained mindful of the present.
This demo presents the ongoing effort to meld the stream query processing capabilities of microsoft StreamInsight with the visualization capabilities of the WorldWide Telescope. This effort provides visualization oppo...
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For many years I had been fruitlessly trying to sell functional programming and Haskell to solve real world problems such as scripting and data-intensive three-tier distributed web applications. The lack of widespread...
ISBN:
(纸本)9781595937865
For many years I had been fruitlessly trying to sell functional programming and Haskell to solve real world problems such as scripting and data-intensive three-tier distributed web applications. The lack of widespread adoption of Haskell is a real pity. Functional programming concepts are key to curing many of the headaches that plague the majority of programmers, who today are forced to use imperative languages. If the mountain won't come to Mohammed, Mohammed must go to the mountain, and so I left academia to join industry. Instead of trying to convince imperative programmers to forget everything they already know and learn something completely new, I decided to infuse existing imperative object-oriented programming languages with functional programming features. As a result, functional programming has finally reached the masses, except that it is called Visual Basic 9 instead of Haskell 98.
Efficient and convenient handling of heterogeneous data is a current challenge for data management systems. In this paper, we discuss several common relational approaches to represent heterogeneity and argue for a des...
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ISBN:
(纸本)9781424418367
Efficient and convenient handling of heterogeneous data is a current challenge for data management systems. In this paper, we discuss several common relational approaches to represent heterogeneity and argue for a design based on a single wide-table, referred to as a flexible schema. For this scenario, we focus on partial indexation and its support for efficient data storage and processing. Filtered indices provide partial indexation functionality in the microsoft sql server product. We describe here the implementation of this feature, including index utilization in queries, index maintenance and query parameterization issues. Our performance experiments validate the expected benefits of the approach in our implementation.
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