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weng
Starting Member
2 Posts |
Posted - 2012-12-04 : 02:20:40
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[url]http://postimage.org/image/9uu1vh9oz/[/url]Based on the blocking statistic image attached as above. What is the possible reason for these blocking : spid -51 - begin tranupdate Master_table_data set sys_value=sys_value +1 where GETDATE()> start_dt and sys_key='LAST_USED_ID'; commitselect sys_value from Master_table_data with(nolock)WHERE GETDATE()>eff_start_dt and sys_key='LAST_USED_LOG_ID' ENDspid -53 - beginset @ErrorMsg='Msg_'+@ErrorMsg;set @SYS_VALUE = NULL select @SYS_VALUE = sys_value from Master_table_data where sys_key=@ErrorMsg if @SYS_VALUE is not nullbegin insert into TXN_AUDIT_LOG select @LogID, GetDate(), @IP, @Flag, @SYS_VALUE endQuestion :1, It seem like the select is issuing a Exclusive lock . Is these possible ? |
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weng
Starting Member
2 Posts |
Posted - 2012-12-04 : 02:43:21
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the table only have 17 rows .the same statement will run in every minutes when there are new data enter from the front end system . The blocking occurs intermittent and update is always block by the exclusive lock. I don't understand how the exclusive lock trigger by a select statement.Additional information on the table:CREATE TABLE [dbo].[Master_table_data]( [SYS_KEY] [nvarchar](30) NOT NULL, [SYS_VALUE] [nvarchar](500) NOT NULL, [EFF_START_DT] [datetime] NOT NULL, [EFF_END_DT] [datetime] NULL, [CREATED_DT] [datetime] NULL, [CREATED_BY] [nvarchar](30) NULL, [MODIFIED_DT] [datetime] NULL, [MODIFIED_BY] [nvarchar](30) NULL, CONSTRAINT [PK_Master_table_data] PRIMARY KEY CLUSTERED ( [SYS_KEY] ASC, [SYS_VALUE] ASC, [EFF_START_DT] ASC) |
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