Replace Database Parameters
This article explains how to change custom parameter values in an Exasol database.
Exasol databases are configured using parameters that are written as key-value pairs in the format "-parameter":"value"
. Parameters that are not explicitly defined will fall back on default values hard-coded in the application. The default values should be adequate for most use cases, but can be changed by adding custom parameter values in the configuration if needed.
This article explains how to update existing custom parameter values.
Invalid parameters will prevent the database from starting. To avoid unnecessary downtime, create a support case to get guidance from Support before you add or change database parameters.
Prerequisites
-
The database must be stopped. For more information, see Stop a Database.
-
The custom parameters that are to be replaced must exist in the database.
Procedure - ConfD
The following examples use ConfD through the command-line tool confd_client, which is available on all database nodes.
-
Connect to the cluster operating system (COS) using
c4 connect -i PLAY_ID -s cos
.Example:
Copy./c4 connect -i c3275f84 -s cos
For more information about how to use
c4 connect
, see How to use c4. -
To find the database name when you are connected to COS, use the ConfD job db_list.
Example:
Copyconfd_client db_list
- MY_DATABASE -
To find currently defined custom parameters, use the ConfD job db_info. Any custom parameters will be listed in the
params:
section.Copyconfd_client db_info db_name: MY_DATABASE | grep params
params: -forceProtocolEncryption=1 -soft_replicationborder_in_numrows=1000000 -
To replace parameters, use the ConfD job db_configure with the attribute
params:
followed by the parameters to be replaced. For example:Copyconfd_client db_configure db_name: MY_DATABASE params: '[-forceProtocolEncryption=0, -soft_replicationborder_in_numrows=2000000]'
-
To verify that the configuration has been updated, use the ConfD job db_info. Any custom parameters will be listed in the
params:
section.Copyconfd_client db_info db_name: MY_DATABASE | grep params
params: -forceProtocolEncryption=0 -soft_replicationborder_in_numrows=2000000