sys.dm_fts_fdhosts (Transact-SQL)

Applies to: yesSQL Server (all supported versions) YesAzure SQL Database

Returns information on the current activity of the filter daemon host or hosts on the server instance.

Column name Data type Description
fdhost_id int ID of the filter daemon host.
fdhost_name nvarchar(120) Name of filter daemon host.
fdhost_process_id int Windows process ID of the filter daemon host.
fdhost_type nvarchar(120) Type of document being processed by the filter daemon host, one of:

Single thread


Huge document
max_thread int Maximum number of threads in the filter daemon host.
batch_count int Number of batches that are being processed in the filter daemon host.


On SQL Server, requires VIEW SERVER STATE permission.
On SQL Database Basic, S0, and S1 service objectives, and for databases in elastic pools, the server admin account or the Azure Active Directory admin account is required. On all other SQL Database service objectives, the VIEW DATABASE STATE permission is required in the database.


The following example returns the name of the filter daemon host and the maximum number of threads in it. It also monitors how many batches are currently being processed in the filter daemon. This information can be used to diagnose performance.

SELECT fdhost_name, batch_count, max_thread FROM sys.dm_fts_fdhosts;  

See Also

Full-Text Search and Semantic Search Dynamic Management Views and Functions (Transact-SQL)
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