常用SQL Server進行性能優化語句

1、鎖監控查看鎖住的表： select request_session_id spid,OBJECT_NAME(resource_associated_entity_id) tableName from sys.dm_tran_locks where resource_type='OBJECT' ...

1、鎖監控

查看鎖住的表：

select   request_session_id   spid,OBJECT_NAME(resource_associated_entity_id) tableName  
from   sys.dm_tran_locks where resource_type='OBJECT'

查看哪個會話引起阻塞並且它們在運行什麼：

SELECT  DTL.[request_session_id] AS [session_id] ,
        DB_NAME(DTL.[resource_database_id]) AS [Database] ,
        DTL.resource_type ,
        CASE WHEN DTL.resource_type IN ( 'DATABASE', 'FILE', 'METADATA' )
             THEN DTL.resource_type
             WHEN DTL.resource_type = 'OBJECT'
             THEN OBJECT_NAME(DTL.resource_associated_entity_id,
                              DTL.[resource_database_id])
             WHEN DTL.resource_type IN ( 'KEY', 'PAGE', 'RID' )
             THEN ( SELECT  OBJECT_NAME([object_id])
                    FROM    sys.partitions
                    WHERE   sys.partitions.hobt_id = DTL.resource_associated_entity_id
                  )
             ELSE 'Unidentified'
        END AS [Parent Object] ,
        DTL.request_mode AS [Lock Type] ,
        DTL.request_status AS [Request Status] ,
        DER.[blocking_session_id] ,
        DES.[login_name] ,
        CASE DTL.request_lifetime
          WHEN 0 THEN DEST_R.TEXT
          ELSE DEST_C.TEXT
        END AS [Statement]
FROM    sys.dm_tran_locks DTL
        LEFT JOIN sys.[dm_exec_requests] DER ON DTL.[request_session_id] = DER.[session_id]
        INNER JOIN sys.dm_exec_sessions DES ON DTL.request_session_id = DES.[session_id]
        INNER JOIN sys.dm_exec_connections DEC ON DTL.[request_session_id] = DEC.[most_recent_session_id]
        OUTER APPLY sys.dm_exec_sql_text(DEC.[most_recent_sql_handle]) AS DEST_C
        OUTER APPLY sys.dm_exec_sql_text(DER.sql_handle) AS DEST_R
WHERE   DTL.[resource_database_id] = DB_ID()
        AND DTL.[resource_type] NOT IN ( 'DATABASE', 'METADATA' )
ORDER BY DTL.[request_session_id];

查看因為單條UPDATE語句鎖住的用戶表：

SELECT  [resource_type] ,
        DB_NAME([resource_database_id]) AS [Database Name] ,
        CASE WHEN DTL.resource_type IN ( 'DATABASE', 'FILE', 'METADATA' )
             THEN DTL.resource_type
             WHEN DTL.resource_type = 'OBJECT'
             THEN OBJECT_NAME(DTL.resource_associated_entity_id,
                              DTL.[resource_database_id])
             WHEN DTL.resource_type IN ( 'KEY', 'PAGE', 'RID' )
             THEN ( SELECT  OBJECT_NAME([object_id])
                    FROM    sys.partitions
                    WHERE   sys.partitions.hobt_id = DTL.resource_associated_entity_id
                  )
             ELSE 'Unidentified'
        END AS requested_object_name ,
        [request_mode] ,
        [resource_description]
FROM    sys.dm_tran_locks DTL
WHERE   DTL.[resource_type] <> 'DATABASE';

單庫中的鎖定和阻塞：

SELECT  DTL.[resource_type] AS [resource type] ,
        CASE WHEN DTL.[resource_type] IN ( 'DATABASE', 'FILE', 'METADATA' )
             THEN DTL.[resource_type]
             WHEN DTL.[resource_type] = 'OBJECT'
             THEN OBJECT_NAME(DTL.resource_associated_entity_id)
             WHEN DTL.[resource_type] IN ( 'KEY', 'PAGE', 'RID' )
             THEN ( SELECT  OBJECT_NAME([object_id])
                    FROM    sys.partitions
                    WHERE   sys.partitions.[hobt_id] = DTL.[resource_associated_entity_id]
                  )
             ELSE 'Unidentified'
        END AS [Parent Object] ,
        DTL.[request_mode] AS [Lock Type] ,
        DTL.[request_status] AS [Request Status] ,
        DOWT.[wait_duration_ms] AS [wait duration ms] ,
        DOWT.[wait_type] AS [wait type] ,
        DOWT.[session_id] AS [blocked session id] ,
        DES_blocked.[login_name] AS [blocked_user] ,
        SUBSTRING(dest_blocked.text, der.statement_start_offset / 2,
                  ( CASE WHEN der.statement_end_offset = -1
                         THEN DATALENGTH(dest_blocked.text)
                         ELSE der.statement_end_offset
                    END - der.statement_start_offset ) / 2) AS [blocked_command] ,
        DOWT.[blocking_session_id] AS [blocking session id] ,
        DES_blocking.[login_name] AS [blocking user] ,
        DEST_blocking.[text] AS [blocking command] ,
        DOWT.resource_description AS [blocking resource detail]
FROM    sys.dm_tran_locks DTL
        INNER JOIN sys.dm_os_waiting_tasks DOWT ON DTL.lock_owner_address = DOWT.resource_address
        INNER JOIN sys.[dm_exec_requests] DER ON DOWT.[session_id] = DER.[session_id]
        INNER JOIN sys.dm_exec_sessions DES_blocked ON DOWT.[session_id] = DES_Blocked.[session_id]
        INNER JOIN sys.dm_exec_sessions DES_blocking ON DOWT.[blocking_session_id] = DES_Blocking.[session_id]
        INNER JOIN sys.dm_exec_connections DEC ON DTL.[request_session_id] = DEC.[most_recent_session_id]
        CROSS APPLY sys.dm_exec_sql_text(DEC.[most_recent_sql_handle]) AS DEST_Blocking
        CROSS APPLY sys.dm_exec_sql_text(DER.sql_handle) AS DEST_Blocked
WHERE   DTL.[resource_database_id] = DB_ID()

識別在行級的鎖定和阻塞：

SELECT  '[' + DB_NAME(ddios.[database_id]) + '].[' + su.[name] + '].['
        + o.[name] + ']' AS [statement] ,
        i.[name] AS 'index_name' ,
        ddios.[partition_number] ,
        ddios.[row_lock_count] ,
        ddios.[row_lock_wait_count] ,
        CAST (100.0 * ddios.[row_lock_wait_count] / ( ddios.[row_lock_count] ) AS DECIMAL(5,
                                                              2)) AS [%_times_blocked] ,
        ddios.[row_lock_wait_in_ms] ,
        CAST (1.0 * ddios.[row_lock_wait_in_ms] / ddios.[row_lock_wait_count] AS DECIMAL(15,
                                                              2)) AS [avg_row_lock_wait_in_ms]
FROM    sys.dm_db_index_operational_stats(DB_ID(), NULL, NULL, NULL) ddios
        INNER JOIN sys.indexes i ON ddios.[object_id] = i.[object_id]
                                    AND i.[index_id] = ddios.[index_id]
        INNER JOIN sys.objects o ON ddios.[object_id] = o.[object_id]
        INNER JOIN sys.sysusers su ON o.[schema_id] = su.[UID]
WHERE   ddios.row_lock_wait_count > 0
        AND OBJECTPROPERTY(ddios.[object_id], 'IsUserTable') = 1
        AND i.[index_id] > 0
ORDER BY ddios.[row_lock_wait_count] DESC ,
        su.[name] ,
        o.[name] ,
        i.[name]

識別閂鎖等待：

SELECT  '[' + DB_NAME() + '].[' + OBJECT_SCHEMA_NAME(ddios.[object_id])
        + '].[' + OBJECT_NAME(ddios.[object_id]) + ']' AS [object_name] ,
        i.[name] AS index_name ,
        ddios.page_io_latch_wait_count ,
        ddios.page_io_latch_wait_in_ms ,
        ( ddios.page_io_latch_wait_in_ms / ddios.page_io_latch_wait_count ) AS avg_page_io_latch_wait_in_ms
FROM    sys.dm_db_index_operational_stats(DB_ID(), NULL, NULL, NULL) ddios
        INNER JOIN sys.indexes i ON ddios.[object_id] = i.[object_id]
                                    AND i.index_id = ddios.index_id
WHERE   ddios.page_io_latch_wait_count > 0
        AND OBJECTPROPERTY(i.object_id, 'IsUserTable') = 1
ORDER BY ddios.page_io_latch_wait_count DESC ,
        avg_page_io_latch_wait_in_ms DESC

識別鎖升級：

SELECT  OBJECT_NAME(ddios.[object_id], ddios.database_id) AS [object_name] ,
        i.name AS index_name ,
        ddios.index_id ,
        ddios.partition_number ,
        ddios.index_lock_promotion_attempt_count ,
        ddios.index_lock_promotion_count ,
        ( ddios.index_lock_promotion_attempt_count
          / ddios.index_lock_promotion_count ) AS percent_success
FROM    sys.dm_db_index_operational_stats(DB_ID(), NULL, NULL, NULL) ddios
        INNER JOIN sys.indexes i ON ddios.object_id = i.object_id
                                    AND ddios.index_id = i.index_id
WHERE   ddios.index_lock_promotion_count > 0
ORDER BY index_lock_promotion_count DESC;

與鎖爭用有關的索引：

SELECT  OBJECT_NAME(ddios.object_id, ddios.database_id) AS object_name ,
        i.name AS index_name ,
        ddios.index_id ,
        ddios.partition_number ,
        ddios.page_lock_wait_count ,
        ddios.page_lock_wait_in_ms ,
        CASE WHEN DDMID.database_id IS NULL THEN 'N'
             ELSE 'Y'
        END AS missing_index_identified
FROM    sys.dm_db_index_operational_stats(DB_ID(), NULL, NULL, NULL) ddios
        INNER JOIN sys.indexes i ON ddios.object_id = i.object_id
                                    AND ddios.index_id = i.index_id
        LEFT OUTER JOIN ( SELECT DISTINCT
                                    database_id ,
                                    object_id
                          FROM      sys.dm_db_missing_index_details
                        ) AS DDMID ON DDMID.database_id = ddios.database_id
                                      AND DDMID.object_id = ddios.object_id
WHERE   ddios.page_lock_wait_in_ms > 0
ORDER BY ddios.page_lock_wait_count DESC;

2、索引監控

未被使用的索引：

SELECT  OBJECT_NAME(i.[object_id]) AS [Table Name] ,
        i.name
FROM    sys.indexes AS i
        INNER JOIN sys.objects AS o ON i.[object_id] = o.[object_id]
WHERE   i.index_id NOT IN ( SELECT  ddius.index_id
                            FROM    sys.dm_db_index_usage_stats AS ddius
                            WHERE   ddius.[object_id] = i.[object_id]
                                    AND i.index_id = ddius.index_id
                                    AND database_id = DB_ID() )
        AND o.[type] = 'U'
ORDER BY OBJECT_NAME(i.[object_id]) ASC;

需要維護但是未被用過的索引：

SELECT  '[' + DB_NAME() + '].[' + su.[name] + '].[' + o.[name] + ']' AS [statement] ,
        i.[name] AS [index_name] ,
        ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] AS [user_reads] ,
        ddius.[user_updates] AS [user_writes] ,
        SUM(SP.rows) AS [total_rows]
FROM    sys.dm_db_index_usage_stats ddius
        INNER JOIN sys.indexes i ON ddius.[object_id] = i.[object_id]
                                    AND i.[index_id] = ddius.[index_id]
        INNER JOIN sys.partitions SP ON ddius.[object_id] = SP.[object_id]
                                        AND SP.[index_id] = ddius.[index_id]
        INNER JOIN sys.objects o ON ddius.[object_id] = o.[object_id]
        INNER JOIN sys.sysusers su ON o.[schema_id] = su.[UID]
WHERE   ddius.[database_id] = DB_ID() -- current database only
        AND OBJECTPROPERTY(ddius.[object_id], 'IsUserTable') = 1
        AND ddius.[index_id] > 0
GROUP BY su.[name] ,
        o.[name] ,
        i.[name] ,
        ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] ,
        ddius.[user_updates]
HAVING  ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] = 0
ORDER BY ddius.[user_updates] DESC ,
        su.[name] ,
        o.[name] ,
        i.[name]

可能不高效的非聚集索引 (writes > reads)：

SELECT  OBJECT_NAME(ddius.[object_id]) AS [Table Name] ,
        i.name AS [Index Name] ,
        i.index_id ,
        user_updates AS [Total Writes] ,
        user_seeks + user_scans + user_lookups AS [Total Reads] ,
        user_updates - ( user_seeks + user_scans + user_lookups ) AS [Difference]
FROM    sys.dm_db_index_usage_stats AS ddius WITH ( NOLOCK )
        INNER JOIN sys.indexes AS i WITH ( NOLOCK ) ON ddius.[object_id] = i.[object_id]
                                                       AND i.index_id = ddius.index_id
WHERE   OBJECTPROPERTY(ddius.[object_id], 'IsUserTable') = 1
        AND ddius.database_id = DB_ID()
        AND user_updates > ( user_seeks + user_scans + user_lookups )
        AND i.index_id > 1
ORDER BY [Difference] DESC ,
        [Total Writes] DESC ,
        [Total Reads] ASC;

沒有用於用戶查詢的索引：

SELECT  '[' + DB_NAME() + '].[' + su.[name] + '].[' + o.[name] + ']' AS [statement] ,
        i.[name] AS [index_name] ,
        ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] AS [user_reads] ,
        ddius.[user_updates] AS [user_writes] ,
        ddios.[leaf_insert_count] ,
        ddios.[leaf_delete_count] ,
        ddios.[leaf_update_count] ,
        ddios.[nonleaf_insert_count] ,
        ddios.[nonleaf_delete_count] ,
        ddios.[nonleaf_update_count]
FROM    sys.dm_db_index_usage_stats ddius
        INNER JOIN sys.indexes i ON ddius.[object_id] = i.[object_id]
                                    AND i.[index_id] = ddius.[index_id]
        INNER JOIN sys.partitions SP ON ddius.[object_id] = SP.[object_id]
                                        AND SP.[index_id] = ddius.[index_id]
        INNER JOIN sys.objects o ON ddius.[object_id] = o.[object_id]
        INNER JOIN sys.sysusers su ON o.[schema_id] = su.[UID]
        INNER JOIN sys.[dm_db_index_operational_stats](DB_ID(), NULL, NULL,