Campbell Fraser

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SQL Server 2012 introduced two innovations targeted for data warehousing workloads: column store indexes and batch (vectorized) processing mode. Together they greatly improve performance of typical data warehouse queries, routinely by 10X and in some cases by a 100X or more. The main limitations of the initial version are addressed in the upcoming release.(More)
—Query optimizers depend heavily on statistics representing column distributions to create efficient query plans. In many cases, though, statistics are outdated or non-existent, and the process of refreshing statistics is very expensive, especially for ad-hoc workloads on ever bigger data. This results in suboptimal plans that severely hurt performance. The(More)
Reliable query optimization greatly depends on accurate Cardinality Estimation (CE), which is inherently inexact as it relies on statistical information. In commercial database systems, cardinality estimation models are sophisticated components that over years of development can become very complex. The code that implements cardinality estimation models,(More)
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