The following query will compare the nonclustered indexes vs the clustered index and determine which index would qualify as the best clustered index based upon the DMV statistics. If a clustered index does not exist on the table, it will also suggest one of the existing nonclustered indexes as the clustered index. DECLARE @NonClusteredSeekPct float [...]
Archive of posts filed under the DMV Queries category.
Find All Queries Run Against a Table
Dynamic management view to find all queries that have been run against a table since the last reboot.
Find Number of Pages Each Database has in BufferPool
This query shows how many pages each database has in the buffer Pool. This will show you the breakdown of memory allocation for each database. SELECT DB_NAME(database_id), COUNT(page_id)as number_pages FROM sys.dm_os_buffer_descriptors WHERE database_id !=32767 GROUP BY database_id ORDER BY database_id
Find Queries with Highest Reads (Highest IO)
SELECT TOP 10 ‘Procedure’ = qt.text ,DiskReads = qs.total_physical_reads — The worst reads, disk reads ,MemoryReads = qs.total_logical_reads –Logical Reads are memory reads ,Executions = qs.execution_count ,CPUTime = qs.total_worker_time ,DiskWaitAndCPUTime = qs.total_elapsed_time ,MemoryWrites = qs.max_logical_writes ,DateCached = qs.creation_time ,DatabaseName = DB_Name(qt.dbid) ,LastExecutionTime = qs.last_execution_time FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qt ORDER BY [...]
A Better sp_who2 using DMVs (sp_who3)
The following code generates the same information found in sp_who2, along with some additional troubleshooting information. It also contains the SQL Statement being run, so instead of having to execute a separate DBCC INPUTBUFFER, the statement being executed is shown in the results. Unlike sp_who2, sp_who3 only shows sessions that have a current executing request. [...]
Find Queries Performing Most Writes (Inserts)
SELECT TOP 10 ‘Procedure’ = qt.text ,DiskReads = qs.total_physical_reads — The worst reads, disk reads ,MemoryReads = qs.total_logical_reads –Logical Reads are memory reads ,Executions = qs.execution_count ,CPUTime = qs.total_worker_time ,DiskWaitAndCPUTime = qs.total_elapsed_time ,MemoryWrites = qs.max_logical_writes ,DateCached = qs.creation_time ,DatabaseName = DB_Name(qt.dbid) ,LastExecutionTime = qs.last_execution_time FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qt ORDER BY [...]
Find Memory Usage of Executing Procedures
To get the query memory usage of currently executing queries run the following: SELECT TEXT ,query_plan ,requested_memory_kb ,granted_memory_kb ,used_memory_kb FROM sys.dm_exec_query_memory_grants emg CROSS APPLY sys.dm_exec_sql_text(sql_handle) CROSS APPLY sys.dm_exec_query_plan(emg.plan_handle) ORDER BY emg.requested_memory_kb DESC
Find Index Usage
The following DMV query retrieves the usage statistics for existing indexes. User Seeks – A high number indicates a well utilized index. User Scans – Number of times the index has been scanned. Could indicate improper ordering of the composite columns User Lookups – Indicates a different index was used for criteria and the actual [...]
Missing Indexes DMV
This query will show the indexes that are missing ordered according to those having the most impact. It will also provide the create index script needed in order to help you create the index. SELECT mid.statement ,migs.avg_total_user_cost * (migs.avg_user_impact / 100.0) * (migs.user_seeks + migs.user_scans) AS improvement_measure,OBJECT_NAME(mid.Object_id), ‘CREATE INDEX [missing_index_' + CONVERT (varchar, mig.index_group_handle) + [...]
Find Long Running Queries
SELECT TOP 10 ObjectName = OBJECT_NAME(qt.objectid) ,DiskReads = qs.total_physical_reads — The worst reads, disk reads ,MemoryReads = qs.total_logical_reads –Logical Reads are memory reads ,Executions = qs.execution_count ,AvgDuration = qs.total_elapsed_time / qs.execution_count ,CPUTime = qs.total_worker_time ,DiskWaitAndCPUTime = qs.total_elapsed_time ,MemoryWrites = qs.max_logical_writes ,DateCached = qs.creation_time ,DatabaseName = DB_Name(qt.dbid) FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qt [...]
