Locks per Process

Previous  Top  Next

The Locks per Process screen shows you locked database objects, grouped per server process ID.


The Locks per Process screen on server Iduna


The window consists of two parts - the processes list and the object list. The processes list shows a list of all available processes that have locks. If you select one of the processes, the right part of the window will list the objects that are locked by the selected process.


In the example screenshot above, you can see that user "sa" on database "Northwind" is clearly doing something with table "Categories".


You can kill a process - and therefore release the lock(s) - by using the context menu in the Processes part or the button on the toolbar.


There are several locking modes:

Shared (S)


Used for operations that do not change or update data (read-only operations), such as a SELECT statement.


Update (U)


Used on resources that can be updated. Prevents a common form of deadlock that occurs when multiple sessions are reading, locking, and potentially updating resources later.


Exclusive (X)


Used for data-modification operations, such as INSERT, UPDATE, or DELETE. Ensures that multiple updates cannot be made to the same resource at the same time.




Used to establish a lock hierarchy. The types of intent locks are: intent shared (IS), intent exclusive (IX), and shared with intent exclusive (SIX).




Used when an operation dependent on the schema of a table is executing. The types of schema locks are: schema modification (Sch-M) and schema stability (Sch-S).


Bulk Update (BU)


Used when bulk-copying data into a table and the TABLOCK hint is specified.



And several lock types:



Row identifier used to lock a single row within a table.




Row lock within an index. Used to protect key ranges in serializable transactions.




Data or index page.




Contiguous group of eight data pages or index pages.




Entire table, including all data and indexes.







For more information on locking, see the Microsoft SQL Server documentation.