CREATE DEFAULT SHADOW ALGORITHM 语法用于创建影子库默认算法规则。
CreateDefaultShadowAlgorithm ::=
'CREATE' 'DEFAULT' 'SHADOW' 'ALGORITHM' ifNotExists? shadowAlgorithm
ifNotExists ::=
'IF' 'NOT' 'EXISTS'
shadowAlgorithm ::=
'TYPE' '(' 'NAME' '=' shadowAlgorithmType ',' propertiesDefiinition ')'
shadowAlgorithmType ::=
string
propertiesDefinition ::=
'PROPERTIES' '(' key '=' value (',' key '=' value)* ')'
key ::=
string
value ::=
literal
shadowAlgorithmType 目前支持 VALUE_MATCH、REGEX_MATCH 和 SIMPLE_HINT;ifNotExists 子句用于避免出现 Duplicate default shadow algorithm 错误。CREATE DEFAULT SHADOW ALGORITHM TYPE(NAME="SIMPLE_HINT", PROPERTIES("shadow"="true", "foo"="bar"));
ifNotExists 子句创建默认影子库压测算法CREATE DEFAULT SHADOW ALGORITHM IF NOT EXISTS TYPE(NAME="SIMPLE_HINT", PROPERTIES("shadow"="true", "foo"="bar"));
CREATE、DEFAULT、SHADOW、ALGORITHM、TYPE、NAME、PROPERTIES
