## 3.5 Configuration Parameter Issues
The SAP HANA database creates alerts if it detects an incorrect setting for any of the most critical configuration parameters.
The following table lists the monitored parameters and related alerts.
Alerts related to configuration
|   Alert ID | Alert Name                           | Parameter                                         | Further Information                                            |
|------------|--------------------------------------|---------------------------------------------------|----------------------------------------------------------------|
|         10 | Delta merge (mergedog) configuration | Indexserver.ini - mergedog - active               | Delta Merge                                                    |
|         16 | Lock wait timeout config- uration    | Indexserver.ini - transaction - lock_wait_timeout | Transactional Problems                                         |
|         32 | Log mode legacy                      | Global.ini - persistence - log_mode               | Issues with Configuration Parameter log_mode (Alert 32 and 33) |
|         33 | Log mode overwrite                   | Global.ini - persistence - log_mode               | Issues with Configuration Parameter log_mode (Alert 32 and 33) |
To check for parameters that are not set according to the default values you can use the following SQL statement:
```
select a.file_name, b.layer_name, b.tenant_name, b.host, b.section, b.key, a.value as defaultvalue, b.currentvalue from sys.m_inifile_contents a join ( select file_name, layer_name, tenant_name, host, section, key, value as currentvalue from sys.m_inifile_contents b where layer_name <> 'DEFAULT' ) b on a.file_name = b.file_name and a.section = b.section and a.key = b.key and a.value <> b.currentvalue
```
Alternatively, use the script 'HANA_Configuration_Parameters_2.00.040+' in the SQL Statement Collection for SAP HANA (see SAP Note 1969700). The output of this script will list all parameters deviating from recommended settings.
##  Note
Default values of parameters may change when updating the SAP HANA database with a new revision. Custom values on the system level and on the host level will not be affected by such updates.
## Correcting Parameter Settings
You can change configuration parameters using the SAP HANA cockpit or the ALTER SYSTEM ALTER CONFIGURATION statement.
All configuration parameters are defined in table CONFIGURATION_PARAMETER_PROPERTIES. You can look up parameter details either in the system using for example SAP HANA cockpit or by referring to the Configuration Parameter Reference Guide in the SAP Help Portal. In addition to basic properties such as data type, unit and a default value the definition includes a flag to indicate if a system restart is required before a changed value becomes effective.
The SAP Note 2600030 - Parameter Recommendations in SAP HANA Environments is updated regularly with version-specific information covering cases where configuration parameter settings other than the default values are recommended.
Usually alerts on incorrect parameter settings include information about correct setting of the parameter. So, unless you have received a specific recommendation from SAP to change the parameter to another value, you can fix the issue by changing the parameter from the Configuration of System Properties monitor of SAP HANA cockpit. You can search for a specific parameter by filtering on the parameter name. In most cases the suggested correct value will be the default value. Most of the parameters can be changed online and do not require any further action; exceptions for common parameters are noted in the reference document referred to above. For more information about how to change parameters, see Memory Information from Logs and Traces .
##  Note
Make sure that you change the parameter in the correct ini-file and section, since the parameter name itself may be not unique.
## Related Information
Delta Merge [page 129]
Transactional Problems [page 167]
Issues with Configuration Parameter log_mode (Alert 33) [page 124]
Memory Information from Logs and Traces [page 66]
SAP Note 2600030
SAP Note 1969700
SAP HANA Configuration Parameter Reference