ALTER READWRITE_SPLITTING RULE

AlterReadwriteSplittingRule ::=
  'ALTER' 'READWRITE_SPLITTING' 'RULE' readwriteSplittingDefinition (',' readwriteSplittingDefinition)*

readwriteSplittingDefinition ::=
  ruleName '(' dataSourceDefinition (',' transactionalReadQueryStrategyDefinition)? (',' loadBalancerDefinition)? ')'

dataSourceDefinition ::=
    'WRITE_STORAGE_UNIT' '=' writeStorageUnitName ',' 'READ_STORAGE_UNITS' '(' storageUnitName (',' storageUnitName)* ')' 

transactionalReadQueryStrategyDefinition ::=
    'TRANSACTIONAL_READ_QUERY_STRATEGY' '=' transactionalReadQueryStrategyType

loadBalancerDefinition ::=
    'TYPE' '(' 'NAME' '=' algorithmType (',' propertiesDefinition)? ')'

ruleName ::=
  identifier

writeStorageUnitName ::=
  identifier

storageUnitName ::=
  identifier

transactionalReadQueryStrategyType ::=
  string

algorithmType ::=
  string

propertiesDefinition ::=
  'PROPERTIES' '(' key '=' value (',' key '=' value)* ')'

key ::=
  string

value ::=
  literal

ALTER READWRITE_SPLITTING RULE ms_group_0 (
    WRITE_STORAGE_UNIT=write_ds,
    READ_STORAGE_UNITS(read_ds_0,read_ds_1),
    TYPE(NAME="random")
);