sys.dm_tran_locks (Transact-SQL)

THIS TOPIC APPLIES TO: yesSQL Server (starting with 2008)yesAzure SQL DatabaseyesAzure SQL Data Warehouse yesParallel Data Warehouse

Returns information about currently active lock manager resources in SQL Server 2017. Each row represents a currently active request to the lock manager for a lock that has been granted or is waiting to be granted.

The columns in the result set are divided into two main groups: resource and request. The resource group describes the resource on which the lock request is being made, and the request group describes the lock request.

Note

To call this from Azure SQL Data Warehouse or Parallel Data Warehouse, use the name sys.dm_pdw_nodes_tran_locks.

Column name Data type Description
resource_type nvarchar(60) Represents the resource type. The value can be one of the following: DATABASE, FILE, OBJECT, PAGE, KEY, EXTENT, RID, APPLICATION, METADATA, HOBT, or ALLOCATION_UNIT.
resource_subtype nvarchar(60) Represents a subtype of resource_type. Acquiring a subtype lock without holding a nonsubtyped lock of the parent type is technically valid. Different subtypes do not conflict with each other or with the nonsubtyped parent type. Not all resource types have subtypes.
resource_database_id int ID of the database under which this resource is scoped. All resources handled by the lock manager are scoped by the database ID.
resource_description nvarchar(256) Description of the resource that contains only information that is not available from other resource columns.
resource_associated_entity_id bigint ID of the entity in a database with which a resource is associated. This can be an object ID, Hobt ID, or an Allocation Unit ID, depending on the resource type.
resource_lock_partition Int ID of the lock partition for a partitioned lock resource. The value for nonpartitioned lock resources is 0.
request_mode nvarchar(60) Mode of the request. For granted requests, this is the granted mode; for waiting requests, this is the mode being requested.
request_type nvarchar(60) Request type. The value is LOCK.
request_status nvarchar(60) Current status of this request. Possible values are GRANTED, CONVERT, WAIT, LOW_PRIORITY_CONVERT, LOW_PRIORITY_WAIT, or ABORT_BLOCKERS. For more information about low priority waits and abort blockers, see the low_priority_lock_wait section of ALTER INDEX (Transact-SQL).
request_reference_count smallint Returns an approximate number of times the same requestor has requested this resource.
request_lifetime int Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
request_session_id int Session ID that currently owns this request. The owning session ID can change for distributed and bound transactions. A value of -2 indicates that the request belongs to an orphaned distributed transaction. A value of -3 indicates that the request belongs to a deferred recovery transaction, such as, a transaction for which a rollback has been deferred at recovery because the rollback could not be completed successfully.
request_exec_context_id int Execution context ID of the process that currently owns this request.
request_request_id int Request ID (batch ID) of the process that currently owns this request. This value will change every time that the active Multiple Active Result Set (MARS) connection for a transaction changes.
request_owner_type nvarchar(60) Entity type that owns the request. Lock manager requests can be owned by a variety of entities. Possible values are:

TRANSACTION = The request is owned by a transaction.

CURSOR = The request is owned by a cursor.

SESSION = The request is owned by a user session.

SHARED_TRANSACTION_WORKSPACE = The request is owned by the shared part of the transaction workspace.

EXCLUSIVE_TRANSACTION_WORKSPACE = The request is owned by the exclusive part of the transaction workspace.

NOTIFICATION_OBJECT = The request is owned by an internal SQL Server component. This component has requested the lock manager to notify it when another component is waiting to take the lock. The FileTable feature is a component that uses this value.

Note: Work spaces are used internally to hold locks for enlisted sessions.
request_owner_id bigint ID of the specific owner of this request.

When a transaction is the owner of the request, this value contains the transaction ID.

When a FileTable is the owner of the request, request_owner_id has one of the following values.



-4 : A FileTable has taken a database lock.

-3 : A FileTable has taken a table lock.

Other value : The value represents a file handle. This value also appears as fcb_id in the dynamic management view sys.dm_filestream_non_transacted_handles (Transact-SQL).
request_owner_guid uniqueidentifier GUID of the specific owner of this request. This value is only used by a distributed transaction where the value corresponds to the MS DTC GUID for that transaction.
request_owner_lockspace_id nvarchar(32) Identified for informational purposes only. Not supported. Future compatibility is not guaranteed. This value represents the lockspace ID of the requestor. The lockspace ID determines whether two requestors are compatible with each other and can be granted locks in modes that would otherwise conflict with one another.
lock_owner_address varbinary(8) Memory address of the internal data structure that is used to track this request. This column can be joined the with resource_address column in sys.dm_os_waiting_tasks.
pdw_node_id int Applies to: Azure SQL Data Warehouse, Parallel Data Warehouse



The identifier for the node that this distribution is on.

Permissions

On SQL Server, requires VIEW SERVER STATE permission.
On SQL Database Premium Tiers, requires the VIEW DATABASE STATE permission in the database. On SQL Database Standard and Basic Tiers, requires the Server admin or an Azure Active Directory admin account.

Remarks

A granted request status indicates that a lock has been granted on a resource to the requestor. A waiting request indicates that the request has not yet been granted. The following waiting-request types are returned by the request_status column:

  • A convert request status indicates that the requestor has already been granted a request for the resource and is currently waiting for an upgrade to the initial request to be granted.

  • A wait request status indicates that the requestor does not currently hold a granted request on the resource.

    Because sys.dm_tran_locks is populated from internal lock manager data structures, maintaining this information does not add extra overhead to regular processing. Materializing the view does require access to the lock manager internal data structures. This can have minor effects on the regular processing in the server. These effects should be unnoticeable and should only affect heavily used resources. Because the data in this view corresponds to live lock manager state, the data can change at any time, and rows are added and removed as locks are acquired and released. This view has no historical information.

    Two requests operate on the same resource only if all the resource-group columns are equal.

    You can control the locking of read operations by using the following tools:

  • SET TRANSACTION ISOLATION LEVEL to specify the level of locking for a session. For more information, see SET TRANSACTION ISOLATION LEVEL (Transact-SQL).

  • Locking table hints to specify the level of locking for an individual reference of a table in a FROM clause. For syntax and restrictions, see Table Hints (Transact-SQL).

    A resource that is running under one session ID can have more than one granted lock. Different entities that are running under one session can each own a lock on the same resource, and the information is displayed in the request_owner_type and request_owner_id columns that are returned by sys.dm_tran_locks. If multiple instances of the same request_owner_type exist, the request_owner_id column is used to distinguish each instance. For distributed transactions, the request_owner_type and the request_owner_guid columns will show the different entity information.

    For example, Session S1 owns a shared lock on Table1; and transaction T1, which is running under session S1, also owns a shared lock on Table1. In this case, the resource_description column that is returned by sys.dm_tran_locks will show two instances of the same resource. The request_owner_type column will show one instance as a session and the other as a transaction. Also, the resource_owner_id column will have different values.

    Multiple cursors that run under one session are indistinguishable and are treated as one entity.

    Distributed transactions that are not associated with a session ID value are orphaned transactions and are assigned the session ID value of -2. For more information, see KILL (Transact-SQL).

Resource Details

The following table lists the resources that are represented in the resource_associated_entity_id column.

Resource type Resource description Resource_associated_entity_id
DATABASE Represents a database. Not applicable
FILE Represents a database file. This file can be either a data or a log file. Not applicable
OBJECT Represents a database object. This object can be a data table, view, stored procedure, extended stored procedure, or any object that has an object ID. Object ID
PAGE Represents a single page in a data file. HoBt ID. This value corresponds to sys.partitions.hobt_id. The HoBt ID is not always available for PAGE resources because the HoBt ID is extra information that can be provided by the caller, and not all callers can provide this information.
KEY Represents a row in an index. HoBt ID. This value corresponds to sys.partitions.hobt_id.
EXTENT Represents a data file extent. An extent is a group of eight contiguous pages. Not applicable
RID Represents a physical row in a heap. HoBt ID. This value corresponds to sys.partitions.hobt_id. The HoBt ID is not always available for RID resources because the HoBt ID is extra information that can be provided by the caller, and not all callers can provide this information.
APPLICATION Represents an application specified resource. Not applicable
METADATA Represents metadata information. Not applicable
HOBT Represents a heap or a B-tree. These are the basic access path structures. HoBt ID. This value corresponds to sys.partitions.hobt_id.
ALLOCATION_UNIT Represents a set of related pages, such as an index partition. Each allocation unit covers a single Index Allocation Map (IAM) chain. Allocation Unit ID. This value corresponds to sys.allocation_units.allocation_unit_id.

The following table lists the subtypes that are associated with each resource type.

ResourceSubType Synchronizes
ALLOCATION_UNIT.BULK_OPERATION_PAGE Pre-allocated pages used for bulk operations.
ALLOCATION_UNIT.PAGE_COUNT Allocation unit page count statistics during deferred drop operations.
DATABASE.BULKOP_BACKUP_DB Database backups with bulk operations.
DATABASE.BULKOP_BACKUP_LOG Database log backups with bulk operations.
DATABASE.CHANGE_TRACKING_CLEANUP Change tracking cleanup tasks.
DATABASE.CT_DDL Database and table-level change tracking DDL operations.
DATABASE.CONVERSATION_PRIORITY Service Broker conversation priority operations such as CREATE BROKER PRIORITY.
DATABASE.DDL Data definition language (DDL) operations with filegroup operations, such as drop.
DATABASE.ENCRYPTION_SCAN TDE encryption synchronization.
DATABASE.PLANGUIDE Plan guide synchronization.
DATABASE.RESOURCE_GOVERNOR_DDL DDL operations for resource governor operations such as ALTER RESOURCE POOL.
DATABASE.SHRINK Database shrink operations.
DATABASE.STARTUP Used for database startup synchronization.
FILE.SHRINK File shrink operations.
HOBT.BULK_OPERATION Heap-optimized bulk load operations with concurrent scan, under these isolation levels: snapshot, read uncommitted, and read committed using row versioning.
HOBT.INDEX_REORGANIZE Heap or index reorganization operations.
OBJECT.COMPILE Stored procedure compile.
OBJECT.INDEX_OPERATION Index operations.
OBJECT.UPDSTATS Statistics updates on a table.
METADATA.ASSEMBLY Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ASSEMBLY_CLR_NAME Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ASSEMBLY_TOKEN Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ASYMMETRIC_KEY Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AUDIT Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AUDIT_ACTIONS Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AUDIT_SPECIFICATION Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AVAILABILITY_GROUP Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CERTIFICATE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CHILD_INSTANCE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.COMPRESSED_FRAGMENT Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.COMPRESSED_ROWSET Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSTATION_ENDPOINT_RECV Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSTATION_ENDPOINT_SEND Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSATION_GROUP Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSATION_PRIORITY Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CREDENTIAL Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CRYPTOGRAPHIC_PROVIDER Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DATA_SPACE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DATABASE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DATABASE_PRINCIPAL Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DB_MIRRORING_SESSION Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DB_MIRRORING_WITNESS Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DB_PRINCIPAL_SID Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ENDPOINT Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ENDPOINT_WEBMETHOD Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.EXPR_COLUMN Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.EXPR_HASH Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_CATALOG Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_INDEX Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_STOPLIST Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.INDEX_EXTENSION_SCHEME Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.INDEXSTATS Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.INSTANTIATED_TYPE_HASH Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.MESSAGE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.METADATA_CACHE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PARTITION_FUNCTION Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PASSWORD_POLICY Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PERMISSIONS Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PLAN_GUIDE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PLAN_GUIDE_HASH Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PLAN_GUIDE_SCOPE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.QNAME Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.QNAME_HASH Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.REMOTE_SERVICE_BINDING Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ROUTE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SCHEMA Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SECURITY_CACHE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SECURITY_DESCRIPTOR Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SEQUENCE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVER_EVENT_SESSIONS Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVER_PRINCIPAL Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE_BROKER_GUID Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE_CONTRACT Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE_MESSAGE_TYPE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.STATS Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SYMMETRIC_KEY Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.USER_TYPE Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.XML_COLLECTION Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.XML_COMPONENT Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.XML_INDEX_QNAME Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.

The following table provides the format of the resource_description column for each resource type.

Resource Format Description
DATABASE Not applicable Database ID is already available in the resource_database_id column.
FILE <file_id> ID of the file that is represented by this resource.
OBJECT <object_id> ID of the object that is represented by this resource. This object can be any object listed in sys.objects, not just a table.
PAGE <file_id>:<page_in_file> Represents the file and page ID of the page that is represented by this resource.
KEY <hash_value> Represents a hash of the key columns from the row that is represented by this resource.
EXTENT <file_id>:<page_in_files> Represents the file and page ID of the extent that is represented by this resource. The extent ID is the same as the page ID of the first page in the extent.
RID <file_id>:<page_in_file>:<row_on_page> Represents the page ID and row ID of the row that is represented by this resource. Note that if the associated object ID is 99, this resource represents one of the eight mixed page slots on the first IAM page of an IAM chain.
APPLICATION <DbPrincipalId>:<upto 32 characters>:(<hash_value>) Represents the ID of the database principal that is used for scoping this application lock resource. Also included are up to 32 characters from the resource string that corresponds to this application lock resource. In certain cases, only 2 characters can be displayed due to the full string no longer being available. This behavior occurs only at database recovery time for application locks that are reacquired as part of the recovery process. The hash value represents a hash of the full resource string that corresponds to this application lock resource.
HOBT Not applicable HoBt ID is included as the resource_associated_entity_id.
ALLOCATION_UNIT Not applicable Allocation Unit ID is included as the resource_associated_entity_id.
METADATA.ASSEMBLY assembly_id = A Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ASSEMBLY_CLR_NAME $qname_id = Q Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ASSEMBLY_TOKEN assembly_id = A, $token_id Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ASSYMMETRIC_KEY asymmetric_key_id = A Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AUDIT audit_id = A Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AUDIT_ACTIONS device_id = D, major_id = M Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AUDIT_SPECIFICATION audit_specification_id = A Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.AVAILABILITY_GROUP availability_group_id = A Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CERTIFICATE certificate_id = C Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CHILD_INSTANCE $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.COMPRESSED_FRAGMENT object_id = O , compressed_fragment_id = C Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.COMPRESSED_ROW object_id = O Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSTATION_ENDPOINT_RECV $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSTATION_ENDPOINT_SEND $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSATION_GROUP $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CONVERSATION_PRIORITY conversation_priority_id = C Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CREDENTIAL credential_id = C Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.CRYPTOGRAPHIC_PROVIDER provider_id = P Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DATA_SPACE data_space_id = D Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DATABASE database_id = D Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DATABASE_PRINCIPAL principal_id = P Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DB_MIRRORING_SESSION database_id = D Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DB_MIRRORING_WITNESS $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.DB_PRINCIPAL_SID $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ENDPOINT endpoint_id = E Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ENDPOINT_WEBMETHOD $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_CATALOG fulltext_catalog_id = F Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_INDEX object_id = O Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.EXPR_COLUMN object_id = O, column_id = C Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.EXPR_HASH object_id = O, $hash = H Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_CATALOG fulltext_catalog_id = F Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_INDEX object_id = O Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.FULLTEXT_STOPLIST fulltext_stoplist_id = F Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.INDEX_EXTENSION_SCHEME index_extension_id = I Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.INDEXSTATS object_id = O, index_id or stats_id = I Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.INSTANTIATED_TYPE_HASH user_type_id = U, hash = H Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.MESSAGE message_id = M Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.METADATA_CACHE $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PARTITION_FUNCTION function_id = F Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PASSWORD_POLICY principal_id = P Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PERMISSIONS class = C Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.PLAN_GUIDE plan_guide_id = P Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA. PLAN_GUIDE_HASH $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA. PLAN_GUIDE_SCOPE scope_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.QNAME $qname_id = Q Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.QNAME_HASH $qname_scope_id = Q, $qname_hash = H Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.REMOTE_SERVICE_BINDING remote_service_binding_id = R Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.ROUTE route_id = R Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SCHEMA schema_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SECURITY_CACHE $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SECURITY_DESCRIPTOR sd_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SEQUENCE $seq_type = S, object_id = O Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVER server_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVER_EVENT_SESSIONS event_session_id = E Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVER_PRINCIPAL principal_id = P Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE service_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE_BROKER_GUID $hash = H1:H2:H3 Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE_CONTRACT service_contract_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SERVICE_MESSAGE_TYPE message_type_id = M Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.STATS object_id = O, stats_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.SYMMETRIC_KEY symmetric_key_id = S Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.USER_TYPE user_type_id = U Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.XML_COLLECTION xml_collection_id = X Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.XML_COMPONENT xml_component_id = X Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
METADATA.XML_INDEX_QNAME object_id = O, $qname_id = Q Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.

The following XEvents are related to partition SWITCH and online index rebuild. For information about syntax, see ALTER TABLE (Transact-SQL) and ALTER INDEX (Transact-SQL).

  • lock_request_priority_state

  • process_killed_by_abort_blockers

  • ddl_with_wait_at_low_priority

    The existing XEvent progress_report_online_index_operation for online index operations was extended by adding partition_number and partition_id.

Examples

A. Using sys.dm_tran_locks with other tools

The following example works with a scenario in which an update operation is blocked by another transaction. By using sys.dm_tran_locks and other tools, information about locking resources is provided.

USE tempdb;  
GO  

-- Create test table and index.  
CREATE TABLE t_lock  
    (  
    c1 int, c2 int  
    );  
GO  

CREATE INDEX t_lock_ci on t_lock(c1);  
GO  

-- Insert values into test table  
INSERT INTO t_lock VALUES (1, 1);  
INSERT INTO t_lock VALUES (2,2);  
INSERT INTO t_lock VALUES (3,3);  
INSERT INTO t_lock VALUES (4,4);  
INSERT INTO t_lock VALUES (5,5);  
INSERT INTO t_lock VALUES (6,6);  
GO  

-- Session 1  
SET TRANSACTION ISOLATION LEVEL READ COMMITTED;  

BEGIN TRAN  
    SELECT c1  
        FROM t_lock  
        WITH(holdlock, rowlock);  

-- Session 2  
BEGIN TRAN  
    UPDATE t_lock SET c1 = 10  

The following query will display lock information. The value for <dbid> should be replaced with the database_id from sys.databases.

SELECT resource_type, resource_associated_entity_id,  
    request_status, request_mode,request_session_id,  
    resource_description   
    FROM sys.dm_tran_locks  
    WHERE resource_database_id = <dbid>  

The following query returns object information by using resource_associated_entity_id from the previous query. This query must be executed while you are connected to the database that contains the object.

SELECT object_name(object_id), *  
    FROM sys.partitions  
    WHERE hobt_id=<resource_associated_entity_id>  

The following query will show blocking information.

SELECT   
        t1.resource_type,  
        t1.resource_database_id,  
        t1.resource_associated_entity_id,  
        t1.request_mode,  
        t1.request_session_id,  
        t2.blocking_session_id  
    FROM sys.dm_tran_locks as t1  
    INNER JOIN sys.dm_os_waiting_tasks as t2  
        ON t1.lock_owner_address = t2.resource_address;  

Release the resources by rolling back the transactions.

-- Session 1  
ROLLBACK;  
GO  

-- Session 2  
ROLLBACK;  
GO  

B. Linking session information to operating system threads

The following example returns information that associates a session ID with a Windows thread ID. The performance of the thread can be monitored in the Windows Performance Monitor. This query does not return session IDs that are currently sleeping.

SELECT STasks.session_id, SThreads.os_thread_id  
    FROM sys.dm_os_tasks AS STasks  
    INNER JOIN sys.dm_os_threads AS SThreads  
        ON STasks.worker_address = SThreads.worker_address  
    WHERE STasks.session_id IS NOT NULL  
    ORDER BY STasks.session_id;  
GO  

See Also

sys.dm_tran_database_transactions (Transact-SQL)
Dynamic Management Views and Functions (Transact-SQL)
Transaction Related Dynamic Management Views and Functions (Transact-SQL)