This topic describes the parameter settings of PolarDB-O. You can modify the parameters in the PolarDB console or on clients.
Modify parameters in the console
For more information, see Change the values of cluster parameters.
Modify parameters on clients
You can execute the following statements to modify parameters on the clients.
Statement | 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 for only 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)