Add new useful extended events

Author: ktaranov

Extended_Events/DarkQueries.sql

@@ -0,0 +1,26 @@
+CREATE EVENT SESSION [DarkQueries] ON SERVER
+  ADD EVENT sqlserver.sql_statement_recompile(
+    ACTION(sqlserver.database_id,sqlserver.sql_text)
+    WHERE ([recompile_cause]=(11))) -- Option (RECOMPILE) Requested
+  ADD TARGET package0.event_file(SET filename=N'DarkQueries');
+  
+ALTER EVENT SESSION [DarkQueries] ON SERVER STATE = START;
+
+
+SELECT DarkQueryData.eventDate,
+       DB_NAME(DarkQueryData.database_id) as DatabaseName,
+       DarkQueryData.object_type,
+       COALESCE(DarkQueryData.sql_text, 
+                OBJECT_NAME(DarkQueryData.object_id, DarkQueryData.database_id)) command,
+       DarkQueryData.recompile_cause
+  FROM sys.fn_xe_file_target_read_file ( 'DarkQueries*xel', null, null, null) event_file_value
+ CROSS APPLY ( SELECT CAST(event_file_value.[event_data] as xml) ) event_file_value_xml ([xml])
+ CROSS APPLY (
+         SELECT event_file_value_xml.[xml].value('(event/@timestamp)[1]', 'datetime') as eventDate,
+                event_file_value_xml.[xml].value('(event/action[@name="sql_text"]/value)[1]', 'nvarchar(max)') as sql_text,
+                event_file_value_xml.[xml].value('(event/data[@name="object_type"]/text)[1]', 'nvarchar(100)') as object_type,
+                event_file_value_xml.[xml].value('(event/data[@name="object_id"]/value)[1]', 'bigint') as object_id,
+                event_file_value_xml.[xml].value('(event/data[@name="source_database_id"]/value)[1]', 'bigint') as database_id,
+                event_file_value_xml.[xml].value('(event/data[@name="recompile_cause"]/text)[1]', 'nvarchar(100)') as recompile_cause
+       ) as DarkQueryData
+ ORDER BY eventDate DESC;

Extended_Events/README.md

@@ -2,3 +2,8 @@
 
 Source links:
  - [Extended Events Microsoft Docs](https://docs.microsoft.com/en-us/sql/relational-databases/extended-events/extended-events)
+ - [Find Your Dark Queries](http://michaeljswart.com/2017/04/finding-your-dark-queries/)
+ - [Finding Blocked Processes and Deadlocks using SQL Server Extended Events](https://www.brentozar.com/archive/2014/03/extended-events-doesnt-hard/)
+ - [What event information can I get by default from SQL Server?](http://dba.stackexchange.com/questions/48052/what-event-information-can-i-get-by-default-from-sql-server)
+ - [Understanding the sql_text Action in Extended Events](https://www.sqlskills.com/blogs/jonathan/understanding-the-sql_text-action-in-extended-events/)
+ - [Extended Events Series (1 of 31) – An Overview of Extended Events](https://www.sqlskills.com/blogs/jonathan/extended-events-overview/)

Extended_Events/Recompile_Histogram.sql

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+CREATE EVENT SESSION Recompile_Histogram ON SERVER 
+  ADD EVENT sqlserver.sql_statement_recompile
+  ADD TARGET package0.histogram (
+      SET filtering_event_name=N'sqlserver.sql_statement_recompile',
+          source=N'recompile_cause',
+          source_type=(0) );
+ 
+ALTER EVENT SESSION Recompile_Histogram ON SERVER STATE = START;
+
+SELECT sv.subclass_name as recompile_cause, 
+       shredded.recompile_count
+  FROM sys.dm_xe_session_targets AS xet  
+  JOIN sys.dm_xe_sessions AS xe  
+       ON (xe.address = xet.event_session_address)  
+ CROSS APPLY ( SELECT CAST(xet.target_data as xml) ) as target_data_xml ([xml])
+ CROSS APPLY target_data_xml.[xml].nodes('/HistogramTarget/Slot') AS nodes (slot_data)
+ CROSS APPLY (
+         SELECT nodes.slot_data.value('(value)[1]', 'int') AS recompile_cause,
+                nodes.slot_data.value('(@count)[1]', 'int') AS recompile_count
+       ) as shredded
+  JOIN sys.trace_subclass_values AS sv
+       ON shredded.recompile_cause = sv.subclass_value
+ WHERE xe.name = 'Recompile_Histogram' 
+   AND sv.trace_event_id = 37 -- SP:Recompile;