Category : Query Plan Analysis - SentryOne Team Blog

Category: Query Plan Analysis

Paul White : Properly Persisted Computed Columns

Paul White : Properly Persisted Computed Columns

Paul White (@SQL_Kiwi) walks through a new trace flag in SQL Server 2016 designed to yield better execution plans (and performance) for queries involving computed columns.

Paul White : UNION ALL Optimization

Paul White : UNION ALL Optimization

Paul White (@SQL_Kiwi) digs into row goals as he explains some interesting and inconsistent behavior with UNION ALL.

SQL Server Optimizer Secrets With Trace Flag 86xx

SQL Server Optimizer Secrets With Trace Flag 86xx

Kevin Kline (@kekline) provides his slides and scripts from his new SQLBits session describing the deep internals exposed by the 86xx series of trace flags.

Erin Stellato : Using DBCC CLONEDATABASE and Query Store for Testing

Erin Stellato : Using DBCC CLONEDATABASE and Query Store for Testing

Erin Stellato demonstrates how to use the new DBCC CLONEDATABASE feature, in combination with Query Store, to test index and query changes.

Rob Farley : Plans with SQL Server 2016 Temporal Tables

For this month's T-SQL Tuesday, Rob Farley looks at some unexpected aspects of query plans you might observe when using Temporal Tables in SQL Server 2016.

Rob Farley : Actual Rows Read Warnings in Plan Explorer

Rob Farley (@rob_farley) looks at information exposed in query plans about residual predicates and actual rows read, showing how Plan Explorer helps identify the issue.

Performance Surprises and Assumptions : DATEADD()

Aaron Bertrand (@AaronBertrand) explores yet another scenario where a date/time function seems to cause the optimizer to behave unexpectedly.

Paul White : Changes to a Writable Partition May Fail Unexpectedly

Paul White (@SQL_Kiwi) shows how an update may fail when a partition has some data on a read-only filegroup, and explains several workarounds.

SQL Sentry v10 : Index Analysis

Aaron Bertrand (@AaronBertrand) provides some insight into a new feature in SQL Sentry v10, and coming soon to Plan Explorer : Index Analysis.

Bad cardinality estimates from SSMS plans – redux

Aaron Bertrand (@AaronBertrand) shares some insight about early changes to Plan Explorer that help to provide you with the most accurate information we can.

Paul White : Another Reason to Use NOEXPAND hints in Enterprise Edition

Paul White (@SQL_Kiwi) goes into detail about another reason you'll want to use the NOEXPAND hint, even when using Enterprise Edition.

Learning all about the SQL Server Plan Cache

The SQL Server plan cache is one of the most important architectural elements for DBAs to understand. Get the slide deck and sample scripts here.

Paul White : Hash Joins on Nullable Columns

Paul White (@SQL_Kiwi) discusses some less well-known query optimizer features and limitations, and explains poor performance of certain hash joins.