Activity Monitor (Locks by Process Page)
Use this page to view information about locks belonging to specific processes.
- Selected process
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Specify the system process ID (SPID) to display what locks are related to each process.
The following columns are displayed for each lock. The order of the columns in the grid can be changed by dragged this column headers to a preferred location.
- Object
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The name of the object being locked.
- Type
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The type of lock. Possible types are:
Type Description RID
Row identifier. Used to lock a single row individually within a table.
Key
A row lock within an index. Used to protect key ranges in serializable transactions.
Page
Data or index page.
Extent
A contiguous group of eight data pages or index pages.
Table
An entire table, including all data and indexes.
Database
An entire database.
Metadata
Descriptive information about the object.
Other types are possible.
- Subtype
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Additional type information. This column may be blank.
- Object ID
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The object ID of the database object that is the subject of the lock.
- Description
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Descriptive information, if any, provided by the thread.
- Request Mode
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The type of lock requested.
Type Description 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 then potentially updating resources later.
Exclusive (X)
Used for data modification operations, such as UPDATE, INSERT, or DELETE. Ensures that multiple updates cannot be made to the same resource at the same time.
Intent
Used to establish a lock hierarchy.
Schema
Used when an operation dependent on the schema of a table is executing. There are two types of schema locks: schema stability (Sch-S) and schema modification (Sch-M).
Bulk update (BU)
Used when bulk copying data into a table and the TABLOCK hint is specified.
RangeS_S
Shared range, shared resource lock; serializable range scan.
RangeS_U
Shared range, update resource lock; serializable update scan.
RangeI_N
Insert range, null resource lock. Used to test ranges before inserting a new key into an index.
RangeX_X
Exclusive range, exclusive resource lock. Used when updating a key in a range.
- Request Type
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The type of object requested.
- Request Status
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The status of the lock request.
Type Description GRANT
Lock was obtained.
WAIT
Lock is blocked by another process.
CNVT
Lock is being converted to another lock. A lock being converted to another lock is held in one mode but is waiting to acquire a stronger lock mode (for example, update to exclusive). When diagnosing blocking issues, a CNVT can be considered similar to a WAIT.
- Owner Type
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The internal owner of the lock, such as TRANSACTION, SESSION, or CURSOR.
- Owner ID
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The owner ID associated with the process.
- Owner GUID
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The GUID of the lock owner.
- Database
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The database containing the locks.
- Process ID
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The process ID that is holding or requesting the lock. This is the same as the Process ID selected at the top of the page.
- Context
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Execution context ID. Represents the ID of a given thread associated with a specific SPID.
- Batch ID
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The batch ID.
