Batch Compilation, Recompilation, and Plan Caching Issues in SQL Server 2005

This paper explains how batches are cached and reused in SQL Server 2005, and suggests best practices on maximizing reuse of cached plans. It also explains scenarios in which batches are recompiled, and gives best practices for reducing or eliminating unnecessary recompilations.

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Statistics Used by the Query Optimizer in Microsoft SQL Server 2005

SQL Server collects statistical information about indexes and column data stored in the database. These statistics are used by the SQL Server query optimizer to choose the most efficient plan for retrieving or updating data. Microsoft has released a whitepaper that describes what data is collected where it is stored, and which commands create, updates, and delete statistics

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