ALTER STORAGE UNIT

Description

The ALTER STORAGE UNIT syntax is used to alter storage units for the currently selected logical database.

Syntax

Grammar Railroad diagram

AlterStorageUnit ::=
  'ALTER' 'STORAGE' 'UNIT' storageUnitDefinition (',' storageUnitDefinition)*
storageUnitDefinition ::=
  storageUnitName '(' ('HOST' '=' hostName ',' 'PORT' '=' port ',' 'DB' '=' dbName | 'URL' '=' url) ',' 'USER' '=' user (',' 'PASSWORD' '=' password)? (',' propertiesDefinition)?')'
storageUnitName ::=
  identifier
hostname ::=
  string
port ::=
  int
dbName ::=
  string
url ::=
  string
user ::=
  string
password ::=
  string
propertiesDefinition ::=
  'PROPERTIES' '(' key '=' value (',' key '=' value)* ')'
key ::=
  string
value ::=
  literal

Supplement

• Before altering the storage units, please confirm that a database exists in Proxy, and execute the use command to successfully select a database;
• ALTER STORAGE UNIT is not allowed to change the real data source associated with this storageUnit;
• ALTER STORAGE UNIT will switch the connection pool. This operation may affect the ongoing business, please use it with caution;
• storageUnitName is case-sensitive;
• storageUnitName needs to be unique within the current database;
• storageUnitName name only allows letters, numbers and _, and must start with a letter;
• poolProperty is used to customize connection pool parameters, key must be the same as the connection pool parameter name.

Example

• Alter storage unit using standard mode

ALTER STORAGE UNIT ds_0 (
    HOST=127.0.0.1,
    PORT=3306,
    DB=db_0,
    USER=root,
    PASSWORD=root
);

• Alter storage unit and set connection pool parameters using standard mode

ALTER STORAGE UNIT ds_0 (
    HOST=127.0.0.1,
    PORT=3306,
    DB=db_1,
    USER=root,
    PASSWORD=root
    PROPERTIES("maximumPoolSize"=10)
);

• Alter storage unit and set connection pool parameters using URL patterns

ALTER STORAGE UNIT ds_0 (
    URL="jdbc:mysql://127.0.0.1:3306/db_2?serverTimezone=UTC&useSSL=false",
    USER=root,
    PASSWORD=root,
    PROPERTIES("maximumPoolSize"=10,"idleTimeout"="30000")
);

Reserved word

ALTER, STORAGE, UNIT, HOST, PORT, DB, USER, PASSWORD, PROPERTIES, URL

Related links

• Reserved word