sys.dm_fts_fdhosts (Transact-SQL)

APPLIES TO: yesSQL Server yesAzure SQL Database noAzure Synapse Analytics (SQL DW) noParallel Data Warehouse

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 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.


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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