How do I modify the parameters of PolarDB - PolarDB - Alibaba Cloud Documentation Center

This topic describes how to modify the parameters of PolarDB in the PolarDB console or on a client.

Modify parameters in the PolarDB console

Log on to the PolarDB console.
In the upper-left corner, select the region where the cluster to which you want to connect is deployed.
Find the cluster and click its ID.
In the left-side navigation pane, choose Settings and Management > Parameters.
Click Modify Parameter.
Modify the cluster parameters and then click Submit Changes.
In the message that appears, click OK.

For more information, see Configure cluster parameters.

Modify parameters on a client

The following table describes the commands that you can run to modify parameters on a client.

Command	Description
`alter database`	Modifies database-level parameters. You can specify different parameter values for different databases. After you modify the parameters, you must reconnect to the session to make new parameter settings to take effect.
`alter role`	Modifies user-level parameters. You can specify different parameter values for different users. The user-level parameter settings override database-level parameter settings. After you modify the parameters, you must reconnect to the session to make new parameter settings to take effect.
`set`	Modifies session-level parameters. The new parameter settings take effect only for the current session. If the session is disconnected, the new parameter settings become invalid.

Examples:

alter database

test1=> alter database test1 set vacuum_cost_delay =10;
ALTER DATABASE

alter role

test1=> alter role test1 pg_db_role_setting;
 setdatabase | setrole |       setcofig
 ------------+---------+------------------------
       41891 |       0 | {vacuum_cost_delay=10}
       0 |     41284 | {random_page_cost=10}
(2 rows)

set

test1=> set random_page_cost=100;
SET
test1=> show random_page_cost;
 random_page_cost
------------------
 100
(1 row)