限制 SQL 临时数据库增长

Question

我在我的生产服务器中面临一个严重的问题，临时数据库呈指数增长。有什么办法可以在不重启SQL服务的情况下恢复tempDB空间？

干杯坎南。

Answer 1

我会忽略建议您更改恢复模型或限制 tempDB(!) 大小的帖子。

您需要追踪增长的实际原因。

如果您打开了默认跟踪（默认情况下它是开箱即用的），您可以通过运行以下命令追溯找出导致增长的原因：

--check if default trace is enabled
if  exists (select 1 from sys.configurations where configuration_id = 1568)
BEGIN

declare @defaultTraceFilepath nvarchar(256)

--get the current trace rollover file
select @defaultTraceFilepath = CONVERT(varchar(256), value) from ::fn_trace_getinfo(0)
where property = 2

SELECT ntusername,loginname, objectname, e.category_id, textdata, starttime,spid,hostname, eventclass,databasename, e.name 
FROM ::fn_trace_gettable(@defaultTraceFilepath,0)
      inner join sys.trace_events e
            on eventclass = trace_event_id
       INNER JOIN sys.trace_categories AS cat
            ON e.category_id = cat.category_id
where 
      databasename = 'tempDB' and 
      cat.category_id = 2 and --database category
      e.trace_event_id in (92,93) --db file growth

END

否则，您可以启动 SQL Profiler 跟踪来捕获这些事件。打开捕获自动增长事件、排序警告和连接警告并查找交叉连接、散列连接或缺少连接条件。

SQL Server 公开了一种通过当前执行的查询来识别 tempDB 空间分配的方法，使用 DMV：

-- This DMV query shows currently executing tasks and tempdb space usage
-- Once you have isolated the task(s) that are generating lots 
-- of internal object allocations, 
-- you can find out which TSQL statement and its query plan 
-- for detailed analysis
select top 10
  t1.session_id, 
  t1.request_id, 
  t1.task_alloc,
  t1.task_dealloc,  
  (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(sql_handle)) AS query_text,
 (SELECT query_plan from sys.dm_exec_query_plan(t2.plan_handle)) as query_plan
from      (Select session_id, request_id,
sum(internal_objects_alloc_page_count +   user_objects_alloc_page_count) as task_alloc,
sum (internal_objects_dealloc_page_count + user_objects_dealloc_page_count) as task_dealloc
       from sys.dm_db_task_space_usage 
       group by session_id, request_id) as t1, 
       sys.dm_exec_requests as t2
where t1.session_id = t2.session_id and 
(t1.request_id = t2.request_id) and 
      t1.session_id > 50
order by t1.task_alloc DESC

（参考）