SELECT DISTINCT TOP 20 est.TEXT AS sqlturkiye_queryText ,DB_NAME(dbid) ,eqs.execution_count AS sqltr_execCount ,eqs.max_elapsed_time AS sqltr_maxelapsedTime ,ISNULL(eqs.total_elapsed_time / NULLIF(eqs.execution_count, 0), 0) AS sqltr_avgElapsedTime ,eqs.creation_time AS sqltr_CreatedTime ,ISNULL(eqs.execution_count / NULLIF(DATEDIFF(s, eqs.creation_time, GETDATE()), 0), 0) AS sqltr_execPerSecond ,total_physical_reads AS sqltr_agPhyRead FROM sys.dm_exec_query_stats eqs CROSS APPLY sys.dm_exec_sql_text(eqs.sql_handle) est ORDER BY eqs.max_elapsed_time DESC
SQL Server 2014 introduces the first major redesign of the SQL Server Query Optimizer cardinality estimation process since version 7.0. The goal for the redesign was to improve accuracy, consistency and supportability of key areas within the cardinality estimation process, ultimately affecting average query execution plan quality and associated workload performance. This paper provides an overview of the primary changes made to the cardinality estimator functionality by the Microsoft query processor team, covering how to enable and disable the new cardinality estimator behavior, and showing how to troubleshoot plan-quality regressions if and when they occur.
2018-06-26
2,974 reads
Erik Darling explains why your queries aren't scaling in production.
2017-09-06
5,344 reads
Aaron Bertrand shows a quick demo that illustrates why you should be very careful about oversizing varchar / nvarchar columns.
2017-08-02
8,420 reads
Greg Larsen explains how you can use Dynamic Management Objects and stored procedures to return your worst performing T-SQL statements.
2017-03-06
5,202 reads
Aaron Bertrand acknowledges that DISTINCT and GROUP BY are usually interchangeable, but shows there are cases where one performs better than the other.
2017-02-23
8,502 reads
