## 4.6.1  Performance Trace
The performance trace is a performance tracing tool built into the SAP HANA database. It records performance indicators for individual query processing steps in the database kernel. You may be requested by SAP Support to provide a performance trace.
Information collected includes the processing time required in a particular step, the data size read and written, network communication, and information specific to the operator or processing-step-specific (for example, number of records used as input and output). The performance trace can be enabled in multiple tenant databases at the same time to analyze cross-database queries.
## Performance Trace Files
Performance trace results are saved to the trace files with file extension * .tpt or * .cpt, which you can access with other diagnosis files. To analyze these files, you need a tool capable of reading the output format (* .tpt and *.cpt). SAP Support has tools for evaluating performance traces.
## Enabling and Configuring the Performance Trace
You can enable and configure the performance trace in the SAP HANA studio or using the ALTER SYSTEM * PERFTRACE SQL statements.
##  Example
To start the performance trace execute ALTER SYSTEM START PERFTRACE .
## Configuration Options
| Option                       | Description                                                                                                                                                                                                                                                                                                                             |
|------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Trace file name              | The name of the file to which the trace data is automatically saved after the performance trace is stopped                                                                                                                                                                                                                              |
| User and application filters | Filters to restrict the trace to a single specific database user, a single specific application user, and a single specific application                                                                                                                                                                                                 |
| Trace execution plans        | You can trace execution plans in addition to the default trace data.                                                                                                                                                                                                                                                                    |
| Function profiler            | The function profiler is a very fine-grained performance tracing tool based on source code instrumentation. It complements the performance trace by providing even more detailed information about the individual processing steps that are done in the database kernel.                                                                |
| Duration                     | How long you want tracing to run If a certain scenario is to be traced, ensure that you enter a value greater than the time it takes the scenario to run. If there is no specific scenario to trace but instead general system performance, then enter a reasonable value. After the specified duration, the trace stops automatically. |
Additional filter options are available in extended mode to restrict the trace data further.
For more information about how to configure the performance trace using SQL, see the SAP HANA SQL and System Views Reference .
## Related Information
ALTER SYSTEM {START | STOP} PERFTRACE Statement (System Management) ALTER SYSTEM SAVE PERFTRACE Statement (System Management) ALTER SYSTEM LOAD PERFTRACE Statement (System Management) m_PERFTRACE System View