Sql server 简单的select语句占用了太多的时间

Sql server 简单的select语句占用了太多的时间,sql-server,tsql,sql-server-2012,rdbms,Sql Server,Tsql,Sql Server 2012,Rdbms,以下简单select语句执行时间过长: select * from sys_letter_intid 系统字母初始化表结构: CREATE TABLE [dbo].[sys_letter_intid]( [intid] [int] NULL, [id] [int] IDENTITY(1,1) NOT NULL, [misc_text] [nvarchar](50) NULL, [misc_Date] [datetime] NULL, [misc_amount] [money] NULL ) O

以下简单select语句执行时间过长:

select * from sys_letter_intid
系统字母初始化表结构:

CREATE TABLE [dbo].[sys_letter_intid](
[intid] [int] NULL,
[id] [int] IDENTITY(1,1) NOT NULL,
[misc_text] [nvarchar](50) NULL,
[misc_Date] [datetime] NULL,
[misc_amount] [money] NULL
) ON [PRIMARY]
不确定行数,因为即使从sys\u letter\u intid中选择COUNT(*)并从sys\u letter\u intid order by intid desc中选择top 1*,执行查询也会花费太多时间

  • 索引空间-0.023 MB
  • 行计数-1
  • 数据空间-0.008MB
sp_lock提供以下输出:

spid   dbid   ObjId       IndId  Type Resource                         Mode     Status
------ ------ ----------- ------ ---- -------------------------------- -------- ------
52     8      0           0      DB                                    S        GRANT
54     8      1185439297  0      TAB                                   IX       GRANT
54     8      0           0      DB                                    S        GRANT
55     5      0           0      DB                                    S        GRANT
56     8      0           0      DB                                    S        GRANT
56     8      2049442375  1      KEY  (716bd5e0da25)                   X        GRANT
56     8      2049442375  0      TAB                                   IX       GRANT
56     8      2049442375  1      PAG  1:29168                          IX       GRANT
58     8      0           0      DB                                    S        GRANT
60     1      2107154552  0      TAB                                   IS       GRANT
60     8      0           0      DB                                    S        GRANT
61     8      0           0      DB                                    S        GRANT
61     8      2049442375  1      PAG  1:29168                          IS       GRANT
61     8      2049442375  1      KEY  (716bd5e0da25)                   S        WAIT
61     8      2049442375  0      TAB                                   IS       GRANT
62     8      0           0      DB                                    S        GRANT
63     5      0           0      DB                                    S        GRANT
64     8      0           0      DB                                    S        GRANT
66     8      0           0      DB                                    S        GRANT
SPID  Status                         Login                                                                          HostName        BlkBy DBName                       Command          CPUTime DiskIO LastBatch      ProgramName                                                        SPID  REQUESTID
----- ------------------------------ ------------------------------------------------------------------------------ --------------- ----- ---------------------------- ---------------- ------- ------ -------------- ------------------------------------------------------------------ ----- ---------
1     BACKGROUND                     sa                                                                               .               .   NULL                         LOG WRITER       234     0      02/27 03:22:02                                                                    1     0    
2     BACKGROUND                     sa                                                                               .               .   NULL                         LAZY WRITER      608     0      02/27 03:22:02                                                                    2     0    
3     BACKGROUND                     sa                                                                               .               .   NULL                         RECOVERY WRITER  93      0      02/27 03:22:02                                                                    3     0    
4     BACKGROUND                     sa                                                                               .               .   NULL                         LOCK MONITOR     0       0      02/27 03:22:02                                                                    4     0    
5     BACKGROUND                     sa                                                                               .               .   master                       SIGNAL HANDLER   0       0      02/27 03:22:02                                                                    5     0    
6     BACKGROUND                     sa                                                                               .               .   NULL                         XE DISPATCHER    62      0      02/27 03:22:02                                                                    6     0    
7     BACKGROUND                     sa                                                                               .               .   NULL                         RESOURCE MONITOR 780     0      02/27 03:22:02                                                                    7     0    
8     BACKGROUND                     sa                                                                               .               .   NULL                         XE TIMER         0       0      02/27 03:22:02                                                                    8     0    
9     BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        0       0      02/27 03:22:40                                                                    9     0    
10    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      02/27 03:22:03                                                                    10    0    
11    BACKGROUND                     sa                                                                               .               .   master                       TRACE QUEUE TASK 0       0      02/27 03:22:03                                                                    11    0    
12    BACKGROUND                     sa                                                                               .               .   NULL                         SYSTEM_HEALTH_MO 0       0      02/27 03:22:04                                                                    12    0    
13    BACKGROUND                     sa                                                                               .               .   NULL                         RECEIVE          312     2      02/27 03:22:04                                                                    13    0    
14    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       159    03/12 22:46:23                                                                    14    0    
15    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       1      03/12 22:46:23                                                                    15    0    
16    BACKGROUND                     sa                                                                               .               .   master                       CHECKPOINT       109     159    02/27 03:22:34                                                                    16    0    
17    BACKGROUND                     sa                                                                               .               .   master                       TASK MANAGER     0       0      02/27 03:22:34                                                                    17    0    
18    BACKGROUND                     sa                                                                               .               .   NULL                         UNKNOWN TOKEN    0       0      02/27 03:23:35                                                                    18    0    
19    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       4      03/12 22:36:22                                                                    19    0    
20    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:46:33                                                                    20    0    
21    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:33:17                                                                    21    0    
22    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:46:33                                                                    22    0    
23    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:50:39                                                                    23    0    
24    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:43:18                                                                    24    0    
25    BACKGROUND                     sa                                                                               .               .   master                       BRKR EVENT HNDLR 0       41     02/27 03:22:40                                                                    25    0    
26    BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        218     0      02/27 03:22:40                                                                    26    0    
27    BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        31      0      02/27 03:22:40                                                                    27    0    
28    BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        0       0      02/27 03:22:40                                                                    28    0    
29    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       7      03/12 22:50:39                                                                    29    0    
30    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:50:39                                                                    30    0    
51    sleeping                       admin                                                                          CGVAK-328         .   master                       AWAITING COMMAND 157     283    03/13 01:15:51 Microsoft SQL Server Management Studio                             51    0    
52    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 16      1      03/13 01:33:08 Microsoft SQL Server Management Studio - Query                     52    0    
53    sleeping                       NT SERVICE\ReportServer$MSSQLSERVER2012                                        WIN-07VQ7EIB4L1   .   ReportServer$MSSQLSERVER2012 AWAITING COMMAND 0       0      03/13 01:40:09 Report Server                                                      53    0    
54    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 218     0      03/13 01:28:50 jTDS                                                               54    0    
55    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 0       0      03/13 01:29:34 jTDS                                                               55    0    
56    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 376     5      03/13 01:31:11 jTDS                                                               56    0    
57    sleeping                       admin                                                                          CGVAK-328         .   master                       AWAITING COMMAND 16      38     03/13 01:40:22 Database Engine Tuning Advisor                                     57    0    
58    sleeping                       NT SERVICE\ReportServer$MSSQLSERVER2012                                        WIN-07VQ7EIB4L1   .   ReportServer$MSSQLSERVER2012 AWAITING COMMAND 0       0      03/13 01:41:14 Report Server                                                      58    0    
59    sleeping                       admin                                                                          CGVAK-328         .   master                       AWAITING COMMAND 0       0      03/13 00:50:47 Database Engine Tuning Advisor                                     59    0    
60    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 125     7      03/13 01:17:27 Microsoft SQL Server Management Studio - Query                     60    0    
62    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 202     0      03/13 01:41:20 jTDS                                                               62    0    
63    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 718     8      03/13 01:29:35 jTDS                                                               63    0    
64    SUSPENDED                      admin                                                                          CGVAK-328       55    PUC                          DELETE           0       0      03/13 01:31:11 jTDS                                                               64    0    
65    sleeping                       admin                                                                          DEVARAJ-PC        .   master                       AWAITING COMMAND 374     0      03/13 01:15:05 Microsoft SQL Server Management Studio                             65    0    
66    sleeping                       admin                                                                          DEVARAJ-PC        .   PUC                          AWAITING COMMAND 0       0      03/13 01:31:50 Microsoft SQL Server Management Studio - Query                     66    0    
67    sleeping                       admin                                                                          DEVARAJ-PC        .   master                       AWAITING COMMAND 0       0      03/13 01:31:46 Microsoft SQL Server Management Studio - Transact-SQL IntelliSense 67    0    
68    sleeping                       admin                                                                          DEVARAJ-PC        .   master                       AWAITING COMMAND 0       0      03/13 01:33:19 Microsoft SQL Server Management Studio - Transact-SQL IntelliSense 68    0    
69    RUNNABLE                       admin                                                                          CGVAK-328         .   PUC                          SELECT INTO      31      8      03/13 01:33:29 Microsoft SQL Server Management Studio - Query                     69    0    

(48 row(s) affected)
SP_Who2提供以下输出:

spid   dbid   ObjId       IndId  Type Resource                         Mode     Status
------ ------ ----------- ------ ---- -------------------------------- -------- ------
52     8      0           0      DB                                    S        GRANT
54     8      1185439297  0      TAB                                   IX       GRANT
54     8      0           0      DB                                    S        GRANT
55     5      0           0      DB                                    S        GRANT
56     8      0           0      DB                                    S        GRANT
56     8      2049442375  1      KEY  (716bd5e0da25)                   X        GRANT
56     8      2049442375  0      TAB                                   IX       GRANT
56     8      2049442375  1      PAG  1:29168                          IX       GRANT
58     8      0           0      DB                                    S        GRANT
60     1      2107154552  0      TAB                                   IS       GRANT
60     8      0           0      DB                                    S        GRANT
61     8      0           0      DB                                    S        GRANT
61     8      2049442375  1      PAG  1:29168                          IS       GRANT
61     8      2049442375  1      KEY  (716bd5e0da25)                   S        WAIT
61     8      2049442375  0      TAB                                   IS       GRANT
62     8      0           0      DB                                    S        GRANT
63     5      0           0      DB                                    S        GRANT
64     8      0           0      DB                                    S        GRANT
66     8      0           0      DB                                    S        GRANT
SPID  Status                         Login                                                                          HostName        BlkBy DBName                       Command          CPUTime DiskIO LastBatch      ProgramName                                                        SPID  REQUESTID
----- ------------------------------ ------------------------------------------------------------------------------ --------------- ----- ---------------------------- ---------------- ------- ------ -------------- ------------------------------------------------------------------ ----- ---------
1     BACKGROUND                     sa                                                                               .               .   NULL                         LOG WRITER       234     0      02/27 03:22:02                                                                    1     0    
2     BACKGROUND                     sa                                                                               .               .   NULL                         LAZY WRITER      608     0      02/27 03:22:02                                                                    2     0    
3     BACKGROUND                     sa                                                                               .               .   NULL                         RECOVERY WRITER  93      0      02/27 03:22:02                                                                    3     0    
4     BACKGROUND                     sa                                                                               .               .   NULL                         LOCK MONITOR     0       0      02/27 03:22:02                                                                    4     0    
5     BACKGROUND                     sa                                                                               .               .   master                       SIGNAL HANDLER   0       0      02/27 03:22:02                                                                    5     0    
6     BACKGROUND                     sa                                                                               .               .   NULL                         XE DISPATCHER    62      0      02/27 03:22:02                                                                    6     0    
7     BACKGROUND                     sa                                                                               .               .   NULL                         RESOURCE MONITOR 780     0      02/27 03:22:02                                                                    7     0    
8     BACKGROUND                     sa                                                                               .               .   NULL                         XE TIMER         0       0      02/27 03:22:02                                                                    8     0    
9     BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        0       0      02/27 03:22:40                                                                    9     0    
10    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      02/27 03:22:03                                                                    10    0    
11    BACKGROUND                     sa                                                                               .               .   master                       TRACE QUEUE TASK 0       0      02/27 03:22:03                                                                    11    0    
12    BACKGROUND                     sa                                                                               .               .   NULL                         SYSTEM_HEALTH_MO 0       0      02/27 03:22:04                                                                    12    0    
13    BACKGROUND                     sa                                                                               .               .   NULL                         RECEIVE          312     2      02/27 03:22:04                                                                    13    0    
14    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       159    03/12 22:46:23                                                                    14    0    
15    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       1      03/12 22:46:23                                                                    15    0    
16    BACKGROUND                     sa                                                                               .               .   master                       CHECKPOINT       109     159    02/27 03:22:34                                                                    16    0    
17    BACKGROUND                     sa                                                                               .               .   master                       TASK MANAGER     0       0      02/27 03:22:34                                                                    17    0    
18    BACKGROUND                     sa                                                                               .               .   NULL                         UNKNOWN TOKEN    0       0      02/27 03:23:35                                                                    18    0    
19    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       4      03/12 22:36:22                                                                    19    0    
20    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:46:33                                                                    20    0    
21    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:33:17                                                                    21    0    
22    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:46:33                                                                    22    0    
23    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:50:39                                                                    23    0    
24    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:43:18                                                                    24    0    
25    BACKGROUND                     sa                                                                               .               .   master                       BRKR EVENT HNDLR 0       41     02/27 03:22:40                                                                    25    0    
26    BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        218     0      02/27 03:22:40                                                                    26    0    
27    BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        31      0      02/27 03:22:40                                                                    27    0    
28    BACKGROUND                     sa                                                                               .               .   master                       BRKR TASK        0       0      02/27 03:22:40                                                                    28    0    
29    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       7      03/12 22:50:39                                                                    29    0    
30    sleeping                       sa                                                                               .               .   master                       TASK MANAGER     0       0      03/12 22:50:39                                                                    30    0    
51    sleeping                       admin                                                                          CGVAK-328         .   master                       AWAITING COMMAND 157     283    03/13 01:15:51 Microsoft SQL Server Management Studio                             51    0    
52    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 16      1      03/13 01:33:08 Microsoft SQL Server Management Studio - Query                     52    0    
53    sleeping                       NT SERVICE\ReportServer$MSSQLSERVER2012                                        WIN-07VQ7EIB4L1   .   ReportServer$MSSQLSERVER2012 AWAITING COMMAND 0       0      03/13 01:40:09 Report Server                                                      53    0    
54    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 218     0      03/13 01:28:50 jTDS                                                               54    0    
55    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 0       0      03/13 01:29:34 jTDS                                                               55    0    
56    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 376     5      03/13 01:31:11 jTDS                                                               56    0    
57    sleeping                       admin                                                                          CGVAK-328         .   master                       AWAITING COMMAND 16      38     03/13 01:40:22 Database Engine Tuning Advisor                                     57    0    
58    sleeping                       NT SERVICE\ReportServer$MSSQLSERVER2012                                        WIN-07VQ7EIB4L1   .   ReportServer$MSSQLSERVER2012 AWAITING COMMAND 0       0      03/13 01:41:14 Report Server                                                      58    0    
59    sleeping                       admin                                                                          CGVAK-328         .   master                       AWAITING COMMAND 0       0      03/13 00:50:47 Database Engine Tuning Advisor                                     59    0    
60    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 125     7      03/13 01:17:27 Microsoft SQL Server Management Studio - Query                     60    0    
62    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 202     0      03/13 01:41:20 jTDS                                                               62    0    
63    sleeping                       admin                                                                          CGVAK-328         .   PUC                          AWAITING COMMAND 718     8      03/13 01:29:35 jTDS                                                               63    0    
64    SUSPENDED                      admin                                                                          CGVAK-328       55    PUC                          DELETE           0       0      03/13 01:31:11 jTDS                                                               64    0    
65    sleeping                       admin                                                                          DEVARAJ-PC        .   master                       AWAITING COMMAND 374     0      03/13 01:15:05 Microsoft SQL Server Management Studio                             65    0    
66    sleeping                       admin                                                                          DEVARAJ-PC        .   PUC                          AWAITING COMMAND 0       0      03/13 01:31:50 Microsoft SQL Server Management Studio - Query                     66    0    
67    sleeping                       admin                                                                          DEVARAJ-PC        .   master                       AWAITING COMMAND 0       0      03/13 01:31:46 Microsoft SQL Server Management Studio - Transact-SQL IntelliSense 67    0    
68    sleeping                       admin                                                                          DEVARAJ-PC        .   master                       AWAITING COMMAND 0       0      03/13 01:33:19 Microsoft SQL Server Management Studio - Transact-SQL IntelliSense 68    0    
69    RUNNABLE                       admin                                                                          CGVAK-328         .   PUC                          SELECT INTO      31      8      03/13 01:33:29 Microsoft SQL Server Management Studio - Query                     69    0    

(48 row(s) affected)
以下是sys.dm_exec_请求中SELECT*的输出,其中阻塞_会话_id为0

我正在使用SQL Server 2012,下面是执行计划

<?xml version="1.0" encoding="utf-16"?>
<ShowPlanXML xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" Version="1.2" Build="11.0.3128.0" xmlns="http://schemas.microsoft.com/sqlserver/2004/07/showplan">
  <BatchSequence>
    <Batch>
      <Statements>
        <StmtSimple StatementCompId="1" StatementEstRows="1" StatementId="1" StatementOptmLevel="TRIVIAL" StatementSubTreeCost="0.0032831" StatementText="select * from sys_letter_intid" StatementType="SELECT" QueryHash="0x806EE30ADB72F191" QueryPlanHash="0x47B522D12A52B90C" RetrievedFromCache="true">
          <StatementSetOptions ANSI_NULLS="true" ANSI_PADDING="true" ANSI_WARNINGS="true" ARITHABORT="true" CONCAT_NULL_YIELDS_NULL="true" NUMERIC_ROUNDABORT="false" QUOTED_IDENTIFIER="true" />
          <QueryPlan CachedPlanSize="8" CompileTime="0" CompileCPU="0" CompileMemory="56">
            <MemoryGrantInfo SerialRequiredMemory="0" SerialDesiredMemory="0" />
            <OptimizerHardwareDependentProperties EstimatedAvailableMemoryGrant="104702" EstimatedPagesCached="9938" EstimatedAvailableDegreeOfParallelism="2" />
            <RelOp AvgRowSize="85" EstimateCPU="0.0001581" EstimateIO="0.003125" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row" EstimateRows="1" LogicalOp="Clustered Index Scan" NodeId="0" Parallel="false" PhysicalOp="Clustered Index Scan" EstimatedTotalSubtreeCost="0.0032831" TableCardinality="1">
              <OutputList>
                <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="intid" />
                <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="id" />
                <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="misc_text" />
                <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="misc_Date" />
                <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="misc_amount" />
              </OutputList>
              <IndexScan Ordered="false" ForcedIndex="false" ForceScan="false" NoExpandHint="false">
                <DefinedValues>
                  <DefinedValue>
                    <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="intid" />
                  </DefinedValue>
                  <DefinedValue>
                    <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="id" />
                  </DefinedValue>
                  <DefinedValue>
                    <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="misc_text" />
                  </DefinedValue>
                  <DefinedValue>
                    <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="misc_Date" />
                  </DefinedValue>
                  <DefinedValue>
                    <ColumnReference Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Column="misc_amount" />
                  </DefinedValue>
                </DefinedValues>
                <Object Database="[PUC]" Schema="[dbo]" Table="[sys_letter_intid]" Index="[IDX_sys_letter_intid]" IndexKind="Clustered" />
              </IndexScan>
            </RelOp>
          </QueryPlan>
        </StmtSimple>
      </Statements>
    </Batch>
  </BatchSequence>
</ShowPlanXML>

为了结束这个问题,感谢Michael Todd、Rbaryyoung和Phil Sandler的评论,SELECT花了很长时间,因为它被另一个进程阻止。在
SELECT
语句上使用
WITH(NOLOCK)
绕过了更新锁(LCK\U M\U),允许语句继续


另请参见HOT theChunKk的评论,其中指出对事务使用不同的隔离级别(例如,
设置事务隔离级别read uncommitted
)是对
SELECT
语句使用
NOLOCK
的替代方法。

可能使用了Begin Tran,如果在使用Begin tran命令后未使用诸如RollBackCommit之类的封闭命令,则即使是简单的查询也会导致执行延迟。

此表有多少行和哪些列?您真的需要表中的所有列(
SELECT*
)和所有行(no
WHERE
子句)?如果您真的需要该表中的所有内容-实际上没有“神奇”的方法来加速聚集索引扫描…该表上有锁吗?如果查询从未完成,您必须得到估计的执行计划,而不是实际的执行计划。因为它只有一行,你要么拥有地球上最慢的计算机,要么@MichaelTodd是正确的。尝试:从sys_letter_intid WITH(NOLOCK)FYI中选择*-使用(NOLOCK)时不需要WITH关键字
select*from table(nolock)
works@John省略WITH关键字是不推荐使用的功能:此功能将在Microsoft SQL Server的未来版本中删除。避免在新的开发工作中使用此功能,并计划修改当前使用此功能的应用程序。这就是我的问题!我不明白为什么它被否决了?无论如何,谢谢D