Who is using space in tempdb, and what is their execution plan?

Who is using space in tempdb, and what is their execution plan?

Who is using space in tempdb, and what is their execution plan? 2 min read
Who is using space in tempdb, and what is their execution plan?

Sometimes tempdb is filling up. Sometimes I just want to monitor the amount of tempdb and check out execution plans of heavy tempdb users while watching performance on a server.

About This Script

This script comes in handy more frequently than I would have thought before I started using it.

  • This script returns space used in tempdb only, regardless of the db context it’s run in, and it only works for tempdb
  • I adapted this from the SQL Server Storage Engine Blog.
select
    t1.session_id
    , t1.request_id
    , task_alloc_GB = cast((t1.task_alloc_pages * 8./1024./1024.) as numeric(10,1))
    , task_dealloc_GB = cast((t1.task_dealloc_pages * 8./1024./1024.) as numeric(10,1))
    , host= case when t1.session_id <= 50 then 'SYS' else s1.host_name end
    , s1.login_name
    , s1.status
    , s1.last_request_start_time
    , s1.last_request_end_time
    , s1.row_count
    , s1.transaction_isolation_level
    , query_text=
        coalesce((SELECT SUBSTRING(text, t2.statement_start_offset/2 + 1,
          (CASE WHEN statement_end_offset = -1
              THEN LEN(CONVERT(nvarchar(max),text)) * 2
                   ELSE statement_end_offset
              END - t2.statement_start_offset)/2)
        FROM sys.dm_exec_sql_text(t2.sql_handle)) , 'Not currently executing')
    , query_plan=(SELECT query_plan from sys.dm_exec_query_plan(t2.plan_handle))
from
    (Select session_id, request_id
    , task_alloc_pages=sum(internal_objects_alloc_page_count +   user_objects_alloc_page_count)
    , task_dealloc_pages = sum (internal_objects_dealloc_page_count + user_objects_dealloc_page_count)
    from sys.dm_db_task_space_usage
    group by session_id, request_id) as t1
left join sys.dm_exec_requests as t2 on
    t1.session_id = t2.session_id
    and t1.request_id = t2.request_id
left join sys.dm_exec_sessions as s1 on
    t1.session_id=s1.session_id
where
    t1.session_id > 50 -- ignore system unless you suspect there's a problem there
    and t1.session_id <> @@SPID -- ignore this request itself
order by t1.task_alloc_pages DESC;
GO