Sharding

Definition

Sharding Table Rule

CREATE SHARDING TABLE RULE shardingTableRuleDefinition [, shardingTableRuleDefinition] ...

ALTER SHARDING TABLE RULE shardingTableRuleDefinition [, shardingTableRuleDefinition] ...

DROP SHARDING TABLE RULE tableName [, tableName] ...

DROP SHARDING ALGORITHM algorithmName [, algorithmName] ...

shardingTableRuleDefinition:
    tableName(resources [, shardingColumn] [, shardingAlgorithm] [, keyGenerateStrategy])

resources:
    RESOURCES(resourceName [, resourceName] ...))

shardingColumn:
    SHARDING_COLUMN=columnName

shardingAlgorithm:
    TYPE(NAME=shardingAlgorithmType [, PROPERTIES([algorithmProperties] )] )

keyGenerateStrategy:
    GENERATED_KEY(COLUMN=columnName,strategyDefinition)

strategyDefinition:
    TYPE(NAME=keyGenerateStrategyType [, PROPERTIES([algorithmProperties] )] )

algorithmProperties:
    algorithmProperty [, algorithmProperty] ...

algorithmProperty:
    key=value
  • RESOURCES needs to use data source resources managed by RDL
  • shardingAlgorithmType specifies the type of automatic sharding algorithm, please refer to Auto Sharding Algorithm
  • keyGenerateStrategyType specifies the distributed primary key generation strategy, please refer to Key Generate Algorithm
  • Duplicate tableName will not be created
  • shardingAlgorithm can be reused by different Sharding Table Rule, so when executing DROP SHARDING TABLE RULE, the corresponding shardingAlgorithm will not be removed
  • To remove shardingAlgorithm, please execute DROP SHARDING ALGORITHM

Sharding Binding Table Rule

CREATE SHARDING BINDING TABLE RULES(bindTableRulesDefinition [, bindTableRulesDefinition] ...)

ALTER SHARDING BINDING TABLE RULES(bindTableRulesDefinition [, bindTableRulesDefinition] ...)

DROP SHARDING BINDING TABLE RULES

bindTableRulesDefinition:
    (tableName [, tableName] ... )
  • ALTER will overwrite the binding table configuration in the database with the new configuration

Sharding Broadcast Table Rule

CREATE SHARDING BROADCAST TABLE RULES (tableName [, tableName] ... )

ALTER SHARDING BROADCAST TABLE RULES (tableName [, tableName] ... )

DROP SHARDING BROADCAST TABLE RULES
  • ALTER will overwrite the broadcast table configuration in the database with the new configuration

Example

Sharding Table Rule

CREATE SHARDING TABLE RULE t_order (
RESOURCES(resource_0,resource_1),
SHARDING_COLUMN=order_id,
TYPE(NAME=hash_mod,PROPERTIES("sharding-count"=4)),
GENERATED_KEY(COLUMN=another_id,TYPE(NAME=snowflake,PROPERTIES("worker-id"=123)))
);

ALTER SHARDING TABLE RULE t_order (
RESOURCES(resource_0,resource_1),
SHARDING_COLUMN=order_id,
TYPE(NAME=hash_mod,PROPERTIES("sharding-count"=10)),
GENERATED_KEY(COLUMN=another_id,TYPE(NAME=snowflake,PROPERTIES("worker-id"=123)))
);

DROP SHARDING TABLE RULE t_order, t_order_item;

DROP SHARDING ALGORITHM t_order_hash_mod;

Sharding Binding Table Rule

CREATE SHARDING BINDING TABLE RULES (
(t_order,t_order_item),
(t_1,t_2)
);

ALTER SHARDING BINDING TABLE RULES (
(t_order,t_order_item)
);

DROP SHARDING BINDING TABLE RULES;

Sharding Broadcast Table Rule

CREATE SHARDING BROADCAST TABLE RULES (t_b,t_a);

ALTER SHARDING BROADCAST TABLE RULES (t_b,t_a,t_3);

DROP SHARDING BROADCAST TABLE RULES;