missing-column-statistics-event-class.md

title	Missing Column Statistics Event Class
description	Missing Column Statistics Event Class
author	WilliamDAssafMSFT
ms.author	wiassaf
ms.date	03/14/2017
ms.service	sql
ms.subservice	supportability
ms.topic	reference
ms.custom	ignite-2025
helpviewer_keywords	Missing Column Statistics event class
monikerRange	=azuresqldb-current || >=sql-server-2016 || >=sql-server-linux-2017 || =azuresqldb-mi-current || =fabric-sqldb

Missing Column Statistics Event Class

[!INCLUDE SQL Server Azure SQL Database Azure SQL Managed Instance FabricSQLDB] The Missing Column Statistics event class indicates that column statistics that could have been useful for the optimizer are not available.

By monitoring the Missing Column Statistics event class, you can determine if there are statistics missing for a column used by a query. This can cause the optimizer to choose a less efficient query plan than expected.

Missing Column Statistics Event Class Data Columns

Data column name	Data type	Description	Column ID	Filterable
ApplicationName	nvarchar	Name of the client application that created the connection to an instance of [!INCLUDEssNoVersion]. This column is populated with the values passed by the application rather than the displayed name of the program.	10	Yes
ClientProcessID	int	ID assigned by the host computer to the process where the client application is running. This data column is populated if the client provides the client process ID.	9	Yes
DatabaseID	int	ID of the database specified by the USE database statement or the default database if no USE database statement has been issued for a given instance. [!INCLUDEssSqlProfiler] displays the name of the database if the ServerName data column is captured in the trace and the server is available. Determine the value for a database by using the DB_ID function.	3	Yes
DatabaseName	nvarchar	Name of the database in which the user statement is running.	35	Yes
EventClass	int	Type of event=79.	27	No
EventSequence	int	Sequence of a given event within the request.	51	No
GroupID	int	ID of the workload group where the SQL Trace event fires.	66	Yes
HostName	nvarchar	Name of the computer on which the client is running. This data column is populated if the client provides the host name. To determine the host name, use the HOST_NAME function.	8	Yes
IsSystem	int	Indicates whether the event occurred on a system process or a user process. 1 = system, 0 = user.	60	Yes
LoginName	nvarchar	Name of the login of the user (either [!INCLUDEssNoVersion] security login or the [!INCLUDEmsCoName] Windows login credentials in the form of DOMAIN\username).	11	Yes
LoginSid	image	Security identification number (SID) of the logged-in user. You can find this information in the sys.server_principals catalog view. Each SID is unique for each login in the server.	41	Yes
NTDomainName	nvarchar	Windows domain to which the user belongs.	7	Yes
NTUserName	nvarchar	Windows user name.	6	Yes
RequestID	int	ID of the request containing the statement.	49	Yes
ServerName	nvarchar	Name of the instance of [!INCLUDEssNoVersion] being traced.	26	No
SessionLoginName	nvarchar	Login name of the user who originated the session. For example, if you connect to [!INCLUDEssNoVersion] using Login1 and execute a statement as Login2, SessionLoginName shows Login1 and LoginName shows Login2. This column displays both [!INCLUDEssNoVersion] and Windows logins.	64	Yes
SPID	int	ID of the session on which the event occurred.	12	Yes
StartTime	datetime	Time at which the event started, if available.	14	Yes
TextData	ntext	List of the columns with missing statistics.	1	Yes
TransactionID	bigint	System-assigned ID of the transaction.	4	Yes
XactSequence	bigint	Token that describes the current transaction.	50	Yes

See Also

sp_trace_setevent (Transact-SQL)
CREATE STATISTICS (Transact-SQL)
Monitor and Respond to Events