| The wait type LCK_M_RS_U is ranked #46 by Stedman Solutions and Database Health Monitor. Wait statistics, in the context of SQL Server, refer to the amount of time that a query spends waiting to access data in the database. When a client application requests data from the database, the request is placed in a queue and the client application must wait for its turn to access the data. The time that the query spends waiting is called a "wait" and is tracked by SQL Server. This information can be used to identify potential performance bottlenecks and optimize the performance of the database. Wait statistics are commonly used by database administrators to diagnose and troubleshoot performance issues in SQL Server. The LCK_M_RS_U wait type in SQL Server occurs when a session is waiting to acquire an update lock on a resource. SQL Server uses locks to protect data integrity and consistency by ensuring that only one session can modify a particular piece of data at a time. Update locks are a type of lock that is used to protect data that is being modified by a session. When a session wants to update a row in a table, it first needs to acquire an update lock on the row in order to prevent other sessions from modifying the same row simultaneously. If a session tries to acquire an update lock on a resource but is unable to do so because the resource is already locked by another session, the session will enter a LCK_M_RS_U wait state. This means that the session will be paused until the lock is released by the other session and becomes available for the waiting session to acquire. LCK_M_RS_U wait types can be caused by a variety of factors, including high concurrency and resource contention in the database. To address LCK_M_RS_U waits, it is important to identify the specific resources that are causing the waits and to optimize the database design and queries to reduce contention for those resources. This may involve indexing strategies, query optimization, and other techniques to improve the performance of the database. Overall, LCK_M_RS_U wait types are an important aspect of SQL Server performance, and understanding and addressing them can help improve the efficiency and scalability of a database. Applies toRelated WaitsLCK_M_BULCK_M_BU_ABORT_BLOCKERS LCK_M_BU_LOW_PRIORITY LCK_M_IS LCK_M_IS_ABORT_BLOCKERS LCK_M_IS_LOW_PRIORITY LCK_M_IU LCK_M_IU_ABORT_BLOCKERS LCK_M_IU_LOW_PRIORITY LCK_M_IX LCK_M_IX_ABORT_BLOCKERS LCK_M_IX_LOW_PRIORITY LCK_M_RIn_NL LCK_M_RIn_NL_ABORT_BLOCKERS LCK_M_RIn_NL_LOW_PRIORITY LCK_M_RIn_S LCK_M_RIn_S_ABORT_BLOCKERS LCK_M_RIn_S_LOW_PRIORITY LCK_M_RIn_U LCK_M_RIn_U_ABORT_BLOCKERS LCK_M_RIn_U_LOW_PRIORITY LCK_M_RIn_X LCK_M_RIn_X_ABORT_BLOCKERS LCK_M_RIn_X_LOW_PRIORITY LCK_M_RS_S LCK_M_RS_S_ABORT_BLOCKERS LCK_M_RS_S_LOW_PRIORITY LCK_M_RS_U_ABORT_BLOCKERS LCK_M_RS_U_LOW_PRIORITY LCK_M_RX_S LCK_M_RX_S_ABORT_BLOCKERS LCK_M_RX_S_LOW_PRIORITY LCK_M_RX_U LCK_M_RX_U_ABORT_BLOCKERS LCK_M_RX_U_LOW_PRIORITY LCK_M_RX_X LCK_M_RX_X_ABORT_BLOCKERS LCK_M_RX_X_LOW_PRIORITY LCK_M_S LCK_M_S_ABORT_BLOCKERS LCK_M_S_LOW_PRIORITY LCK_M_SCH_M LCK_M_SCH_M_ABORT_BLOCKERS LCK_M_SCH_M_LOW_PRIORITY LCK_M_SCH_S LCK_M_SCH_S_ABORT_BLOCKERS LCK_M_SCH_S_LOW_PRIORITY LCK_M_SIU LCK_M_SIU_ABORT_BLOCKERS LCK_M_SIU_LOW_PRIORITY LCK_M_SIX LCK_M_SIX_ABORT_BLOCKERS LCK_M_SIX_LOW_PRIORITY LCK_M_U LCK_M_U_ABORT_BLOCKERS LCK_M_U_LOW_PRIORITY LCK_M_UIX LCK_M_UIX_ABORT_BLOCKERS LCK_M_UIX_LOW_PRIORITY LCK_M_X LCK_M_X_ABORT_BLOCKERS LCK_M_X_LOW_PRIORITY See AlsoAll Wait Types |  |