02Mar 2009 by Grant Fritchey 9 Comments

More Refinements on the Missing Indexes Query

SQL Server, T-SQL
Greg Larson posted a really nice query to find worst performing stored procedures in your system. He put in all kinds of attributes to make it customizable, changing the definition of "worst" to different measures,etc. Great query in general. In it he linked to sys.dm_exec_plan_attributes and got the db_id attribute. Duh! So instead of spelunking through the XML to retrieve the database name, I can pull the db_id and use the DB_NAME function. Cleans things up considerably. Thanks Greg. Here's the cleaned up code: WITH XMLNAMESPACES ('http://schemas.microsoft.com/sqlserver/2004/07/showplan' AS sp) SELECT DB_NAME(CAST(pa.value AS INT)) ,s.sql_handle ,s.total_elapsed_time ,s.last_execution_time ,s.execution_count ,s.total_logical_writes ,s.total_logical_reads ,s.min_elapsed_time ,s.max_elapsed_time --,s.query_hash ,p.query_plan ,p.query_plan.value(N'(sp:ShowPlanXML/sp:BatchSequence/sp:Batch/sp:Statements/sp:StmtSimple/sp:QueryPlan/sp:MissingIndexes/sp:MissingIndexGroup/sp:MissingIndex/@Table)[1]', 'NVARCHAR(256)') AS TableName ,p.query_plan.value(N'(/sp:ShowPlanXML/sp:BatchSequence/sp:Batch/sp:Statements/sp:StmtSimple/sp:QueryPlan/sp:MissingIndexes/sp:MissingIndexGroup/sp:MissingIndex/@Schema)[1]', 'NVARCHAR(256)') AS SchemaName ,p.query_plan.value(N'(/sp:ShowPlanXML/sp:BatchSequence/sp:Batch/sp:Statements/sp:StmtSimple/sp:QueryPlan/sp:MissingIndexes/sp:MissingIndexGroup/@Impact)[1]', 'DECIMAL(6,4)') AS ProjectedImpact ,ColumnGroup.value('./@Usage', 'NVARCHAR(256)') AS ColumnGroupUsage ,ColumnGroupColumn.value('./@Name', 'NVARCHAR(256)') AS ColumnName FROM (SELECT TOP 20 s.sql_handle ,s.plan_handle ,s.total_elapsed_time…
Read More
13Jan 2009 by Grant Fritchey No Comments

Red Gate Crib Sheet Compendium

SQL Server, T-SQL
Red Gate has compiled a bunch of it's Cribsheets into a single E-book, the SQL Server Cribsheet Compendium. It's pretty cool. I've got two entries in there, performance tuning and backups & restores, along with great articles from Robyn Page, Phil Factor, Robert Sheldon and Amirthalingam Prasanna, pretty heady company. It's worth a look.
Read More
18Dec 2008 by Grant Fritchey 15 Comments

Profiler Research

SQL Server
A question came up on SQL Server Central as to why or how Profiler could bring down the production server.  I was aware of the fact that Profiler caused problems and that's why you should always use a server-side trace on production systems. Duh! Of course.... But why? I didn't have an answer. I just "knew" what everyone told me. So I set out to do some research. Initially I hit my favorite source of information on SQL Server (and it should be yours too) the Books Online. Here is what I was reading on the architecture of Profiler. Good, but not enough. I still want more information, so I've gone out a'wanderin' through the interwebs. First, Linchi Shea has this great set of tests comparing Profiler to server side…
Read More