MSSQLWIKI

Monitoring Tempdb space usage and identifying the session and query which Consumes Tempdb

The total space used by Tempdb consists of 

1. User Objects 

2.  Internal Objects

3. Version Store

4. Free Space.

Use  Below Query to Track which objects (above) is consuming pace in TempDb. 
 

SELECT

SUM(unallocated_extent_page_count) AS [free pages], (SUM(unallocated_extent_page_count)*1.0/128) AS [free space in MB],SUM(version_store_reserved_page_count) AS [version store pages used],

(SUM(version_store_reserved_page_count)*1.0/128) AS [version store space in MB],SUM(internal_object_reserved_page_count) AS [internal object pages used],

(SUM(internal_object_reserved_page_count)*1.0/128) AS [internal object space in [MB],SUM(user_object_reserved_page_count) AS [user object pages used],

(SUM(user_object_reserved_page_count)*1.0/128) AS [user object space in MB]

FROM sys.dm_db_file_space_usage;

go

Once you have identified the objects identify the query and session which is consuming tempdb using the query listed below

–Use below query to identify which Query and Session is consuming the space in TempDB

 
SELECT R1.session_id, R1.request_id, R1.Task_request_internal_objects_alloc_page_count, R1.Task_request_internal_objects_dealloc_page_count,

R1.Task_request_user_objects_alloc_page_count,R1.Task_request_user_objects_dealloc_page_count,R3.Session_request_internal_objects_alloc_page_count ,

R3.Session_request_internal_objects_dealloc_page_count,R3.Session_request_user_objects_alloc_page_count,R3.Session_request_user_objects_dealloc_page_count,

R2.sql_handle, RL2.text as SQLText, R2.statement_start_offset, R2.statement_end_offset, R2.plan_handle FROM (SELECT session_id, request_id, 

SUM(internal_objects_alloc_page_count) AS Task_request_internal_objects_alloc_page_count, SUM(internal_objects_dealloc_page_count)AS 

Task_request_internal_objects_dealloc_page_count,SUM(user_objects_alloc_page_count) AS Task_request_user_objects_alloc_page_count,

SUM(user_objects_dealloc_page_count)AS Task_request_user_objects_dealloc_page_count FROM sys.dm_db_task_space_usage 

GROUP BY session_id, request_id) R1 INNER JOIN (SELECT session_id, SUM(internal_objects_alloc_page_count) AS Session_request_internal_objects_alloc_page_count,

SUM(internal_objects_dealloc_page_count)AS Session_request_internal_objects_dealloc_page_count,SUM(user_objects_alloc_page_count) AS Session_request_user_objects_alloc_page_count,

SUM(user_objects_dealloc_page_count)AS Session_request_user_objects_dealloc_page_count FROM sys.dm_db_Session_space_usage 

GROUP BY session_id) R3 on R1.session_id = R3.session_id 

left outer JOIN sys.dm_exec_requests R2 ON R1.session_id = R2.session_id and R1.request_id = R2.request_id

OUTER APPLY sys.dm_exec_sql_text(R2.sql_handle) AS RL2
Where 
Task_request_internal_objects_alloc_page_count >0 or  
Task_request_internal_objects_dealloc_page_count>0 or 
Task_request_user_objects_alloc_page_count >0 or 
Task_request_user_objects_dealloc_page_count >0 or 
Session_request_internal_objects_alloc_page_count >0 or 
Session_request_internal_objects_dealloc_page_count >0 or 
Session_request_user_objects_alloc_page_count >0 or 
Session_request_user_objects_dealloc_page_count >0 

Known issues related to TEMPDB Shrink

FIX: The used space in the tempdb database increases continuously when you run a query that creates internal objects in the tempdb database in SQL Server 2005

Thank you,

Karthick P.K | My Facebook Page |My Site| Blog space| Twitter