Execution Plans

Plan Guides are like duct tape

Stabilizing Execution Plans: Plan Guides and NORECOMPUTE

What could go wrong? Sometimes you end up in a good plan / bad plan situation: an important query runs just fine most of the time. The query is parameterized, a good execution plan gets re-used, everything is cool. But sometimes, a “bad plan” gets compiled and starts to be reused. This is “bad” parameter sniffing. “Bad plans” can…
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The Art of the Execution Plan

Execution Plans
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There’s beauty everywhere – even in SQL Server.  I was just staring at this plan when I was struck by its beauty: Stored Procedure Part 1 Oh, sure, it’s ugly, and I recoiled in horror at first, but when you get over that reaction, there’s an amazing amount of stuff there.  Someone – probably many…
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Simon Sabin’s talk on query performance

Execution Plans
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At #SQLbits, Simon Sabin (Twitter) talked about car crash queries: queries that suddenly have bad performance out of nowhere, yet if you copy/paste them into SQL Server Management Studio, they run quickly.  The culprit is often parameter sniffing: the engine looks at the query and builds a plan, but if the parameters in the WHERE…
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