Description
You can specify an identifier in the tracefile_identifier parameter to filter lines iteratively in the trace log.
Privilege requirements
Query variables
You can execute the
SHOW VARIABLESstatement or query theSYS.TENANT_VIRTUAL_SESSION_VARIABLEview (Oracle mode) orinformation_schema.SESSION_VARIABLESview (MySQL mode) in thesystenant or user tenant to view the values of the session system variables.Modify variables
You can directly modify the values of system variables in the
systenant and user tenants.
Attributes
Description
tracefile_identifier specifies content to be added to logs to facilitate the filtering of line iteration tracking logs.
Privilege requirements
Query variables
systenants and all user tenants can execute theSHOW VARIABLESstatement or query theSYS.TENANT_VIRTUAL_SESSION_VARIABLEview (Oracle mode) or theinformation_schema.SESSION_VARIABLESview (MySQL mode) to view the values of Session system variables.Modify variables
systenants and all user tenants can directly modify the values of Session system variables in their own tenants.
Attributes
| Attribute | Description |
|---|---|
| Parameters | varchar |
| Default value | Empty string |
| Value range | NULL |
| Scope | Session |
| Is modifiable | Yes. You can use the SET statement to modify the parameter. |
Instructions
The TRACING or STAT hint can be used to specify to the execution engine to print all statements during the execution of an operator. To easily search for these statements, you can specify a string, such as XXXYYYZZZ or MY_TRACE, for the tracefile_identifier option and output this string and the statements to a log file.
Examples
Specify the MY_TRACE string to include the line content in the log for later search.
obclient> SET tracefile_identifier = 'MY_TRACE';