ALTER SHARDING TABLE REFERENCE RULE

Description

The ALTER SHARDING TABLE REFERENCE RULE syntax is used to alter sharding table reference rule.

Syntax

Grammar Railroad diagram

AlterShardingTableReferenceRule ::=
  'ALTER' 'SHARDING' 'TABLE' 'REFERENCE' 'RULE'  referenceRelationshipDefinition  (',' referenceRelationshipDefinition)*
referenceRelationshipDefinition ::=
  ruleName '(' tableName (',' tableName)* ')'
tableName ::=
  identifier

Supplement

• A sharding table can only be associated with one sharding table reference rule;
• The referenced sharding tables should be sharded in the same storage units and have the same number of sharding nodes. For example ds_${0..1}.t_order_${0..1} and ds_${0..1}.t_order_item_${0..1};
• The referenced sharding tables should use consistent sharding algorithms. For example t_order_{order_id % 2} and t_order_item_{order_item_id % 2};

Example

1. Alter a sharding table reference rule

ALTER SHARDING TABLE REFERENCE RULE ref_0 (t_order,t_order_item);

2. Alter multiple sharding table reference rules

ALTER SHARDING TABLE REFERENCE RULE ref_0 (t_order,t_order_item), ref_1 (t_product,t_product_item);

Reserved word

ALTER, SHARDING, TABLE, REFERENCE, RULE

Related links

• Reserved word
• CREATE SHARDING TABLE RULE