20211105 1546 sys.dm_xe_sessions 4 undocumented columns

Author: WilliamDAssafMSFT

docs/relational-databases/system-dynamic-management-views/sys-dm-xe-sessions-transact-sql.md

@@ -1,8 +1,8 @@
 ---
 description: "sys.dm_xe_sessions (Transact-SQL)"
-title: "sys.dm_xe_sessions (Transact-SQL) | Microsoft Docs"
+title: "sys.dm_xe_sessions (Transact-SQL)""
 ms.custom: ""
-ms.date: "06/10/2016"
+ms.date: "11/05/2021"
 ms.prod: sql
 ms.reviewer: ""
 ms.technology: system-objects
@@ -17,7 +17,6 @@ dev_langs:
 helpviewer_keywords: 
   - "sys.dm_xe_sessions dynamic management view"
   - "extended events [SQL Server], views"
-ms.assetid: defd6efb-9507-4247-a91f-dc6ff5841e17
 author: WilliamDAssafMSFT
 ms.author: wiassaf
 ---
@@ -28,8 +27,8 @@ ms.author: wiassaf
 
 |Column name|Data type|Description|  
 |-----------------|---------------|-----------------|  
-|address|**varbinary(8)**|The memory address of the session. address is unique across the local system. Is not nullable.|  
-|name|**nvarchar(256)**|The name of the session. name is unique across the local system. Is not nullable.|  
+|address|**varbinary(8)**|The memory address of the session. `address` is unique across the local system. Is not nullable.|  
+|name|**nvarchar(256)**|The name of the session. `name` is unique across the local system. Is not nullable.|  
 |pending_buffers|**int**|The number of full buffers that are pending processing. Is not nullable.|  
 |total_regular_buffers|**int**|The total number of regular buffers that are associated with the session. Is not nullable.<br /><br /> Note: Regular buffers are used most of the time. These buffers are of sufficient size to hold many events. Typically, there will be three or more buffers per session. The number of regular buffers is automatically determined by the server, based on the memory partitioning that is set through the MEMORY_PARTITION_MODE option. The size of the regular buffers is equal to the value of the MAX_MEMORY option (default of 4 MB), divided by the number of buffers. For more information about the MEMORY_PARTITION_MODE and the MAX_MEMORY options, see [CREATE EVENT SESSION &#40;Transact-SQL&#41;](../../t-sql/statements/create-event-session-transact-sql.md).|  
 |regular_buffer_size|**bigint**|The regular buffer size, in bytes. Is not nullable.|  
@@ -39,17 +38,17 @@ ms.author: wiassaf
 |buffer_policy_flags|**int**|A bitmap that indicates how session event buffers behave when all the buffers are full and a new event is fired. Is not nullable.|  
 |buffer_policy_desc|**nvarchar(256)**|A description that indicates how session event buffers behave when all the buffers are full and a new event is fired.  Is not nullable. buffer_policy_desc  can be one of the following:<br /><br /> Drop event<br /><br /> Do not drop events<br /><br /> Drop full buffer<br /><br /> Allocate new buffer|  
 |flags|**int**|A bitmap that indicates the flags that have been set on the session. Is not nullable.|  
-|flag_desc|**nvarchar(256)**|A description of the flags set on the session.  Is not nullable. flag_desc can be any combination of the following:<br /><br /> Flush buffers on close<br /><br /> Dedicated dispatcher<br /><br /> Allow recursive events|  
+|flag_desc|**nvarchar(256)**|A description of the flags set on the session.  Is not nullable. `flag_desc` can be any combination of the following:<br /><br /> Flush buffers on close<br /><br /> Dedicated dispatcher<br /><br /> Allow recursive events|  
 |dropped_event_count|**int**|The number of events that were dropped when the buffers were full. This value is **0** if the buffer policy is "Drop full buffer" or "Do not drop events". Is not nullable.|  
 |dropped_buffer_count|**int**|The number of buffers that were dropped when the buffers were full. This value is **0** if the buffer policy is set to "Drop event" or "Do not drop events". Is not nullable.|  
 |blocked_event_fire_time|**int**|The length of time that event firings were blocked when buffers were full. This value is **0** if the buffer policy is "Drop full buffer" or "Drop event". Is not nullable.|  
 |create_time|**datetime**|The time that the session was created. Is not nullable.|  
 |largest_event_dropped_size|**int**|The size of the largest event that did not fit into the session buffer. Is not nullable.|  
-|session_source|**nvarchar(256)**|The source of the session. Is not nullable. Introduced in sql server 2014.  Valid Values are internal and
-server.  The examples of sessions flagged as internals are hkenginexesession and sp_server_diagnostics session.  On the other hand, the examples of sessions flagged as servers are system_health and telemetry_xevents |  
-|buffer_processed_count|**bigint**|The number of buffers that have been processed. Is not nullable.  Introduced in sql server 2017.|
-|buffer_full_count|**bigint**|The number of buffers that are currently full. Is not nullable.  Introduced in sql server 2017.|  
-|total_bytes_generated|**bigint**|The total number of bytes that has been generated. Is not nullable.  Introduced in sql server 2017.|  
+|session_source|**nvarchar(256)**|**Applies to:** SQL Server 2014 and later. The scope of the session. Is not nullable.<BR><BR>"server" = session scoped to the server, including user sessions.<BR>"internal" = certain internal sessions, such as the sp_server_diagnostics session.<BR>"*database_name*" = for database-scoped sessions.|  
+|buffer_processed_count|**bigint**|**Applies to:** SQL Server 2017 and later. The number of buffers processed by the session. Is not nullable.|
+|buffer_full_count|**bigint**|**Applies to:** SQL Server 2017 and later. The number of buffers that were full when they were processed. Is not nullable.|  
+|total_bytes_generated|**bigint**|**Applies to:** SQL Server 2017 and later. The number of actual bytes that the extended events session has generated. This information is collected when session is processing buffers. |  
+
 ## Permissions  
  Requires VIEW SERVER STATE permission on the server.