sys.dm_fts_fdhosts (Transact-SQL)

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance

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 Multi-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.

Permissions

On SQL Server and SQL Managed Instance, requires VIEW SERVER STATE permission.

On SQL Database Basic, S0, and S1 service objectives, and for databases in elastic pools, the server admin account, the Microsoft Entra admin account, or membership in the ##MS_ServerStateReader## server role is required. On all other SQL Database service objectives, either the VIEW DATABASE STATE permission on the database, or membership in the ##MS_ServerStateReader## server role is required.

Permissions for SQL Server 2022 and later

Requires VIEW SERVER PERFORMANCE STATE permission on the server.

Examples

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;  
GO  

See Also

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