The Essentials: DMV’s and T-SQL for the DBA Rocky Mountain Tech Tri-Fecta

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The Essentials: DMV’s and T-SQL for the DBA Agenda – DMV’s Categories Dive in and try them out – T-SQL for internals / DMV’s Utilizing DMV’s How DMV’s can work for you DDL Triggers Plan Guides Rocky Mountain Tech Tri-Fecta

DMV’s DMV – Definition Dynamic Management Views (and functions) – Return server state information that can be used to monitor the health of a server instance, diagnose problems, and tune performance.* MSFT – 2008 BOL Rocky Mountain Tech Tri-Fecta

DMV Categories » Change Data Capture Related Dynamic Management Views » Query Notifications Related Dynamic Management Views » Common Language Runtime Related Dynamic Management Views » Replication Related Dynamic Management Views » Database Mirroring Related Dynamic Management Views » Resource Governor Dynamic Management Views » Database Related Dynamic Management Views » Service Broker Related Dynamic Management Views » Execution Related Dynamic Management Views and Functions » SQL Server Extended Events Dynamic Management Views » Full-Text Search Related Dynamic Management Views » SQL Server Operating System Related Dynamic Management Views » Index Related Dynamic Management Views and Functions » Transaction Related Dynamic Management Views and Functions » I/O Related Dynamic Management Views and Functions » Security Related Dynamic Management Views » Object Related Dynamic Management Views and Functions Rocky Mountain Tech Tri-Fecta

DMV’s Challenge – Increasingly large environments – Increasingly complex environments Hardware / Database consolidation SQL Server “Sprawl” – Toolset knowledge needed… increasing, quickly » Revamped DTS to SSIS » Revamped SSRS » Improved SSAS » CLR, FileStream, CTE’s, Spatial Datatypes, compression, ABC’s, XYZ’s Rocky Mountain Tech Tri-Fecta

DMV’s DMV - The toolset you can’t live without! Two scopes: – Server & Database Live in the sys Schema Queries for nearly everything – Tuning, Performance related issues, Backup history, Index analysis, Memory, Disk and CPU analysis SQL Server 2008 – Additional 46 DMV’s Rocky Mountain Tech Tri-Fecta

Key DMV’s – Sys.dm_os_sys_info – General Server Info – Sys.dm_exec_requests – Sp_who(2) +++ – Sys.dm_db_index_operational_stats – Sp_lock +++ – Sys.dm_db_index_usage_stats – Base DMV for Index Analysis and Recommendations – Msdb.dbo.backupset – Base table for backup history Rocky Mountain Tech Tri-Fecta

Key DMV’s – Sys.dm_exec_cached_plans – Shows query plans that are cached by SQL Server – For query plans, this DMV maps to the syscacheobjects table in SQL Server 2000 – Sys.dm_exec_query_stats – Performance statistics for cached query plans – Top 10 … – Sys.dm_io_virtual_file_stats – I/O stats for data and log files – Sys.dm_os_memory_pools – Monitors Cache memory Rocky Mountain Tech Tri-Fecta

Key DMV’s – Sys.dm_exec_sql_text – Returns the text of the SQL batch that is identified by the specified sql_handle. – This table-valued function replaces the system function fn_get_sql – Obtained from: » Sys.dm_exec_query_stats » Sys.dm_exec_requests » Sys.dm_exec_cursors » Sys.dm_exec_xml_handles » Sys.dm_exec_query_memory_grants » Sys.dm_exec_connections Rocky Mountain Tech Tri-Fecta

DMV Demo Putting it together… Physical Environment – CPU, Memory, SQL Server start time Backup History – Server, Database, Size, Duration etc… SP_who…? – Tons of great information Indexing – Usage, Analysis, Good, Bad… T-SQL statements – Good or Bad, how can you tell? Rocky Mountain Tech Tri-Fecta

DMV Demo Putting it together… Cache – Adhoc / dynamic – Re-using of cache plans? – Memory breakdown of all compiled objects Set Options – Which ones? Top 10 – Physical Reads – Logical Reads Rocky Mountain Tech Tri-Fecta

DDL Triggers GREAT for auditing changes – What changed? – Who changed it? – When did it change? – Quick Demo – *note the Create_Statistics criteria in the Create Trigger Rocky Mountain Tech Tri-Fecta

Plan Guides Demo Putting it together… Cache Things to look for : – Determine if the adhoc or dynamic statements are generating plans that are re-used, or in this case, not being re-used. select Count (*), refcounts, usecounts, objtype, left(text,50) from sys.dm_Exec_cached_plans cross apply sys.dm_exec_sql_text(plan_handle) where cacheobjtype = 'Compiled Plan’ and objtype = 'Adhoc' and usecounts = 1 group by refcounts, usecounts, objtype, left(text,50) order by 1 desc CountRefcountUsecountobjtypesql – first 50 characters… AdhocSelect DISTINCT TOP 100 W………… AdhocSELECT TOP 1000 W……… Adhocselect distinct top 100 v.W……… – Means that there are 4811 plans for three nearly identical statements – Significant memory required for caching plans – Finite amount of cache for plans Rocky Mountain Tech Tri-Fecta

The Essentials – DMV’s and T-SQL for the DBA Summary – DMV’s Meta-Data for your enterprise Help yourself, your team and your management – DDL Trigger – Consistency, consistency, consistency – Great audit tool – Plan Guides DMV Meta-Data drives exact prescription HAVE FUN! Rocky Mountain Tech Tri-Fecta

The Essentials – DMV’s and T-SQL for the DBA Resources – Rocky Mountain Tri-Fecta! – Local User Group – SQL Server Books On Line – SQL Server 2008 Performance Studio Rocky Mountain Tech Tri-Fecta

The Essentials – DMV’s and T-SQL for the DBA Thank you! – Questions DataRealized.com Rocky Mountain Tech Tri-Fecta