SQLPerformance.com - SentryOne Team Blog

SQLPerformance.com

SQLPerformance.com is about providing innovative and practical solutions for improving SQL Server performance. Whether you are running a 3rd party application database where very little can be changed, or you are a DBA at a site where getting the application developers to change anything is next to impossible, industry experts including Paul Randal, Jonathan Kehayias, Erin Stellato and Paul White will cover both the "how" and the "why."
Monica Rathbun : I/O Troubleshooting

Monica Rathbun : I/O Troubleshooting

Monica Rathburn (@SQLEspresso) talks about a few of the more common elements she always checks for when troubleshooting I/O problems.

Paul White : Cardinality Estimation for a Predicate on a COUNT Expression

Paul White : Cardinality Estimation for a Predicate on a COUNT Expression

Paul White (@SQL_Kiwi) takes you on an optimizer journey, exploring how SQL Server comes up with cardinality estimates for COUNT queries.

Derik Hammer : Myths : Table variables are always in-memory

Derik Hammer : Myths : Table variables are always in-memory

Guest author Derik Hammer (@SQLHammer) dismisses the common myth that table variables perform better than #temp tables because they are always in memory.

Andy Mallon : What the heck is a DTU?

Andy Mallon : What the heck is a DTU?

Andy Mallon (@AMtwo) explains DTUs (Database Transaction Units) and the differences you might see between the documentation and practical usage.

Glenn Berry : Choosing a Processor for SQL Server 2016 Standard Edition

Glenn Berry : Choosing a Processor for SQL Server 2016 Standard Edition

Glenn Berry (@GlennAlanBerry) explains why you need to be very careful about your physical processor choice when configuring servers to run SQL Server 2016 Standard Edition.

Performance Myths : Clustered vs. Non-Clustered Indexes

Performance Myths : Clustered vs. Non-Clustered Indexes

Aaron Bertrand (@AaronBertrand) kicks off his "Performance Myths" series, showing a "redundant" non-clustered index outperforming the clustered index with the same key.

A new series on performance-related SQL Server myths

A new series on performance-related SQL Server myths

Aaron Bertrand (@AaronBertrand) begins a new series aimed at debunking common myths about SQL Server performance.

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 : Using AT TIME ZONE to fix an old report

Rob Farley : Using AT TIME ZONE to fix an old report

Rob Farley (@rob_farley) contributes to T-SQL Tuesday #87, showing how he would use AT TIME ZONE to simplify reports based on an end user's time zone.

Follow-up #1 on leading wildcard seeks

Follow-up #1 on leading wildcard seeks

Aaron Bertrand (@AaronBertrand) shows how to implement simple triggers that maintain trigram-type tables used for better supporting wildcard searches.

One way to get an index seek for a leading %wildcard

One way to get an index seek for a leading %wildcard

In an effort to make leading wildcard searches sargable, Aaron Bertrand plays around with a trigram-type implementation in SQL Server.

Performance Surprises and Assumptions : GROUP BY vs. DISTINCT

Performance Surprises and Assumptions : GROUP BY vs. DISTINCT

Aaron Bertrand acknowledges that DISTINCT and GROUP BY are usually interchangeable, but shows there are cases where one performs better than the other.

Erin Stellato : Compression and its Effects on Performance

Erin Stellato : Compression and its Effects on Performance

Erin Stellato (@erinstellato) takes a look at the new COMPRESS and DECOMPRESS functions, comparing their impact on space and performance to traditional data compression.

Photo credit: rsdio

Rob Farley : Estimated Number of Rows to be Read

Rob Farley : Estimated Number of Rows to be Read

Rob Farley (@rob_farley) uses this month's T-SQL Tuesday to show off the results of one of his Connect items : Estimated Number of Rows to be Read.

SQL Server v.Next : STRING_AGG Performance, Part 2

SQL Server v.Next : STRING_AGG Performance, Part 2

Aaron Bertrand (@AaronBertrand) starts digging deeper into the performance of string concatenation methods STRING_AGG and FOR XML PATH.