sys.dm_fts_memory_buffers

Returns information about memory buffers belonging to a specific memory pool that are used as part of a full-text crawl or a full-text crawl range. This dynamic management view can be used to determine the shared memory usage of a full-text population.

Column name	Data type	Description
pool_id	int	ID of the allocated memory pool. 0 = Small buffers 1 = Large buffers
memory_address	varbinary(8)	Address of the allocated memory buffer.
name	nvarchar(8000)	Name of the shared memory buffer for which this allocation was made.
is_free	bit	Current state of memory buffer. 0 = Busy 1 = Free
row_count	int	Number of rows that this buffer is currently handling.
bytes_used	int	Amount, in bytes, of memory in use in this buffer.
percent_used	int	Percentage of allocated memory used.

Permissions

Requires VIEW SERVER STATE permission on the server.

Physical Joins

Relationship Cardinalities

From	To	Relationship
dm_fts_memory_buffers.pool_id	dm_fts_memory_pools.pool_id	Many-to-one

Examples

A. Returning shared memory usage for all active populations.

The following example returns the shared memory usage for all active full-text populations.

SELECT SUM(pools.buffer_size) FROM sys.dm_fts_memory_pools pools
    JOIN sys.dm_fts_memory_buffers buffers 
    ON (pools.pool_id = buffers.pool_id)
    WHERE buffers.is_free = 0

B. Determining the efficiency of full-text shared memory usage

The following example returns the average percentage of memory that is being used for all active full-text memory buffers.

SELECT AVG(percent_used) AS "memory usage efficiency" 
    FROM sys.dm_fts_memory_buffers 
    WHERE is_free = 0

See Also

Reference

Dynamic Management Views and Functions
Full-Text Search Related Dynamic Management Views

Help and Information

Getting SQL Server 2005 Assistance

Change History

Release	History
12 December 2006	New content: Added the examples. Changed content: Fixed the description of the is_free field.