Sharding

Definition

Sharding Table Rule

SHOW SHARDING TABLE tableRule | RULES [FROM schemaName]

SHOW SHARDING ALGORITHMS [FROM schemaName]

tableRule:
    RULE tableName
  • Support query all data fragmentation rules and specified table query
  • Support query all sharding algorithms

Sharding Binding Table Rule

SHOW SHARDING BINDING TABLE RULES [FROM schemaName]

Sharding Broadcast Table Rule

SHOW SHARDING BROADCAST TABLE RULES [FROM schemaName]

Description

Sharding Table Rule

Column Description
table Logical table name
actual_data_nodes Actual data node
actual_data_sources Actual data source（Displayed when creating rules by RDL）
database_strategy_type Database sharding strategy type
database_sharding_column Database sharding column
database_sharding_algorithm_type Database sharding algorithm type
database_sharding_algorithm_props Database sharding algorithm parameter
table_strategy_type Table sharding strategy type
table_sharding_column Table sharding column
table_sharding_algorithm_type Database sharding algorithm type
table_sharding_algorithm_props Database sharding algorithm parameter
key_generate_column Distributed primary key generation column
key_generator_type Distributed primary key generation type
key_generator_props Distributed primary key generation parameter

Sharding Algorithms

Column Description
name Sharding algorithm name
type Sharding algorithm type
props Sharding algorithm parameters

Sharding Binding Table Rule

Column Description
sharding_binding_tables sharding Binding Table list

Sharding Broadcast Table Rule

Column Description
sharding_broadcast_tables sharding Broadcast Table list

Example

Sharding Table Rule

SHOW SHARDING TABLE RULES

mysql> show sharding table rules;
+--------------+---------------------------------+-------------------+----------------------+------------------------+-------------------------------+----------------------------------------+-------------------+---------------------+----------------------------+---------------------------------------------------+-------------------+------------------+-------------------+
| table        | actual_data_nodes               | actual_data_sources | database_strategy_type | database_sharding_column | database_sharding_algorithm_type | database_sharding_algorithm_props         | table_strategy_type | table_sharding_column | table_sharding_algorithm_type | table_sharding_algorithm_props                       | key_generate_column | key_generator_type | key_generator_props |
+--------------+---------------------------------+-------------------+----------------------+------------------------+-------------------------------+----------------------------------------+-------------------+---------------------+----------------------------+---------------------------------------------------+-------------------+------------------+-------------------+
| t_order      | ds_${0..1}.t_order_${0..1}      |                   | INLINE               | user_id                | INLINE                        | algorithm-expression:ds_${user_id % 2} | INLINE            | order_id            | INLINE                     | algorithm-expression:t_order_${order_id % 2}      | order_id          | SNOWFLAKE        | worker-id:123     |
| t_order_item | ds_${0..1}.t_order_item_${0..1} |                   | INLINE               | user_id                | INLINE                        | algorithm-expression:ds_${user_id % 2} | INLINE            | order_id            | INLINE                     | algorithm-expression:t_order_item_${order_id % 2} | order_item_id     | SNOWFLAKE        | worker-id:123     |
| t2           |                                 | ds_0,ds_1         |                      |                        |                               |                                        | mod               | id                  | mod                        | sharding-count:10                                 |                   |                  |                   |
+--------------+---------------------------------+-------------------+----------------------+------------------------+-------------------------------+----------------------------------------+-------------------+---------------------+----------------------------+---------------------------------------------------+-------------------+------------------+-------------------+
3 rows in set (0.02 sec)

SHOW SHARDING TABLE RULE tableName

mysql> show sharding table rule t_order;
+---------+----------------------------+-------------------+----------------------+------------------------+-------------------------------+----------------------------------------+-------------------+---------------------+----------------------------+----------------------------------------------+-------------------+------------------+-------------------+
| table   | actual_data_nodes          | actual_data_sources | database_strategy_type | database_sharding_column | database_sharding_algorithm_type | database_sharding_algorithm_props         | table_strategy_type | table_sharding_column | table_sharding_algorithm_type | table_sharding_algorithm_props                  | key_generate_column | key_generator_type | key_generator_props |
+---------+----------------------------+-------------------+----------------------+------------------------+-------------------------------+----------------------------------------+-------------------+---------------------+----------------------------+----------------------------------------------+-------------------+------------------+-------------------+
| t_order | ds_${0..1}.t_order_${0..1} |                   | INLINE               | user_id                | INLINE                        | algorithm-expression:ds_${user_id % 2} | INLINE            | order_id            | INLINE                     | algorithm-expression:t_order_${order_id % 2} | order_id          | SNOWFLAKE        | worker-id:123     |
+---------+----------------------------+-------------------+----------------------+------------------------+-------------------------------+----------------------------------------+-------------------+---------------------+----------------------------+----------------------------------------------+-------------------+------------------+-------------------+
1 row in set (0.01 sec)

SHOW SHARDING ALGORITHMS

mysql> show sharding algorithms;
+-------------------------+--------+-----------------------------------------------------+
| name                    | type   | props                                               |
+-------------------------+--------------------------------------------------------------+
| t_order_inline          | INLINE | algorithm-expression=t_order_${order_id % 2}        |
| t_order_item_inline     | INLINE | algorithm-expression=t_order_item_${order_id % 2}   |
+-------------------------+--------+-----------------------------------------------------+
2 row in set (0.01 sec)

Sharding Binding Table Rule

mysql> show sharding binding table rules from sharding_db;
+----------------------+
| sharding_binding_tables |
+----------------------+
| t_order,t_order_item |
| t1,t2                |
+----------------------+
2 rows in set (0.00 sec)

Sharding Broadcast Table Rule

mysql> show sharding broadcast table rules;
+------------------------+
| sharding_broadcast_tables |
+------------------------+
| t_1                    |
| t_2                    |
+------------------------+
2 rows in set (0.00 sec)