SQL Server Audit Records
The SQL Server Audit feature enables you to audit server-level and database-level groups of events and events. For more information, see SQL Server Audit (Database Engine). SQL Server.
Audits consist of zero or more audit action items, which are recorded to an audit target. The audit target can be a binary file, the Windows Application event log, or the Windows Security event log. The records sent to the target can contain the elements described in the following table:
|Column name||Description||Type||Always available|
|event_time||Date/time when the auditable action is fired.||datetime2||Yes|
|sequence_no||Tracks the sequence of records within a single audit record that was too large to fit in the write buffer for audits.||int||Yes|
|action_id||ID of the action
Tip: To use action_id as a predicate it must be converted from a character string to a numeric value. For more information, see Filter SQL Server Audit on action_id / class_type predicate.
|succeeded||Indicates whether or not the permission check of the action triggering the audit event succeeded or failed.||bit
- 1 = Success,
0 = Fail
|permission_bitmask||When applicable, shows the permissions that were granted, denied, or revoked||bigint||No|
|is_column_permission||Flag indicating a column level permission||bit
- 1 = True,
0 = False
|session_id||ID of the session on which the event occurred.||int||Yes|
|server_principal_id||ID of the login context that the action is performed in.||int||Yes|
|database_principal_id||ID of the database user context that the action is performed in.||int||No|
|object_ id||The primary ID of the entity on which the audit occurred. This ID can be:
|target_server_principal_id||Server principal that the auditable action applies to.||int||Yes|
|target_database_principal_id||Database principal that the auditable action applies to.||int||No|
|class_type||Type of auditable entity that the audit occurs on.||varchar(2)||Yes|
|session_server_principal_name||Server principal for the session.||sysname||Yes|
|server_principal_sid||Current login SID.||varbinary||Yes|
|target_server_principal_name||Target login of the action.||sysname||No|
|target_server_principal_sid||SID of the target login.||varbinary||No|
|target_database_principal_name||Target user of the action.||sysname||No|
|server_instance_name||Name of the server instance where the audit occurred. Uses the standard machine\instance format.||nvarchar(120)||Yes|
|database_name||The database context in which the action occurred.||sysname||No|
|schema_name||The schema context in which the action occurred.||sysname||No|
|object_name||The name of the entity on which the audit occurred. This name can be:
TSQL statement (if any)
|statement||TSQL statement (if any)||nvarchar(4000)||No|
|additional_information||Any additional information about the event, stored as XML.||nvarchar(4000)||No|
Some actions do not populate a column's value because it might be non-applicable to the action.
SQL Server Audit stores 4000 characters of data for character fields in an audit record. When the additional_information and statement values returned from an auditable action return more than 4000 characters, the sequence_no column is used to write multiple records into the audit report for a single audit action to record this data. The process is as follows:
The statement column is divided into 4000 characters.
SQL Server Audit writes as the first row for the audit record with the partial data. All the other fields are duplicated in each row.
The sequence_no value is incremented.
This process is repeated until all the data is recorded.
You can connect the data by reading the rows sequentially using the sequence_no value, and the event_Time, action_id and session_id columns to identify the action.