Sharding

Syntax

Sharding Table Rule

SHOW SHARDING TABLE tableRule | RULES [FROM schemaName]

SHOW SHARDING ALGORITHMS [FROM schemaName]

SHOW UNUSED SHARDING ALGORITHMS [FROM schemaName]

SHOW SHARDING KEY GENERATORS [FROM schemaName]

SHOW UNUSED SHARDING KEY GENERATORS [FROM schemaName]

SHOW SHARDING TABLE RULES USED KEY GENERATOR keyGeneratorName [FROM schemaName]

SHOW DEFAULT SHARDING STRATEGY 

SHOW SHARDING TABLE NODES;

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]

Sharding Scaling Rule

SHOW SHARDING SCALING RULES [FROM schemaName]

Return Value 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 properties
table_strategy_type Table sharding strategy type
table_sharding_column Table sharding column
table_sharding_algorithm_type Table sharding algorithm type
table_sharding_algorithm_props Table sharding algorithm properties
key_generate_column Sharding key generator column
key_generator_type Sharding key generator type
key_generator_props Sharding key generator properties

Sharding Algorithms

Column Description
name Sharding algorithm name
type Sharding algorithm type
props Sharding algorithm properties

Unused Sharding Algorithms

Column Description
name Sharding algorithm name
type Sharding algorithm type
props Sharding algorithm properties

Sharding key generators

Column Description
name Sharding key generator name
type Sharding key generator type
props Sharding key generator properties

Unused Sharding Key Generators

Column Description
name Sharding key generator name
type Sharding key generator type
props Sharding key generator properties

Default Sharding Strategy

Column Description
name Strategy name
type Sharding strategy type
sharding_column Sharding column
sharding_algorithm_name Sharding algorithm name
sharding_algorithm_type Sharding algorithm type
sharding_algorithm_props Sharding algorithm properties

Sharding Table Nodes

Column Description
name Sharding rule name
nodes Sharding nodes

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

Sharding Scaling Rule

Column Description
name name of sharding scaling rule
input data read configuration
output data write configuration
stream_channel algorithm of stream channel
completion_detector algorithm of completion detecting
data_consistency_checker algorithm of data consistency checking

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        |                   |
| 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        |                   |
| 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        |                   |
+---------+----------------------------+-------------------+----------------------+------------------------+-------------------------------+----------------------------------------+-------------------+---------------------+----------------------------+----------------------------------------------+-------------------+------------------+-------------------+
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)

SHOW UNUSED SHARDING ALGORITHMS

mysql> SHOW UNUSED SHARDING ALGORITHMS;
+---------------+--------+-----------------------------------------------------+
| name          | type   | props                                               |
+---------------+--------+-----------------------------------------------------+
| t1_inline     | INLINE | algorithm-expression=t_order_${order_id % 2}        |
+---------------+--------+-----------------------------------------------------+
1 row in set (0.01 sec)

SHOW SHARDING KEY GENERATORS

mysql> SHOW SHARDING KEY GENERATORS;
+------------------------+-----------+-----------------+
| name                   | type      | props           |
+------------------------+-----------+-----------------+
| t_order_snowflake      | snowflake |                 |
| t_order_item_snowflake | snowflake |                 |
| uuid_key_generator     | uuid      |                 |
+------------------------+-----------+-----------------+
3 row in set (0.01 sec)

SHOW UNUSED SHARDING KEY GENERATORS

mysql> SHOW UNUSED SHARDING KEY GENERATORS;
+------------------------+-----------+-----------------+
| name                   | type      | props           |
+------------------------+-----------+-----------------+
| uuid_key_generator     | uuid      |                 |
+------------------------+-----------+-----------------+
1 row in set (0.01 sec)

SHOW SHARDING TABLE RULES USED KEY GENERATOR keyGeneratorName

mysql> SHOW SHARDING TABLE RULES USED KEY GENERATOR keyGeneratorName;
+------------------------+-----------+-----------------+
| schema                 | type      | name            |
+------------------------+-----------+-----------------+
| sharding_db            | table     | t_order         |
+------------------------+-----------+-----------------+
1 row in set (0.01 sec)

SHOW DEFAULT SHARDING STRATEGY

mysql> SHOW DEFAULT SHARDING STRATEGY ;

+----------+---------+--------------------+-------------------------+-------------------------+------------------------------------------+
| name     | type    | sharding_column    | sharding_algorithm_name | sharding_algorithm_type | sharding_algorithm_props                 |
+----------+---------+--------------------+-------------------------+-------------------------+------------------------------------------+
| TABLE    | NONE    |                    |                         |                         |                                          |
| DATABASE | STANDARD| order_id           | database_inline         | INLINE                  | {algorithm-expression=ds_${user_id % 2}} |
+----------+---------+--------------------+-------------------------+-------------------------+------------------------------------------+
2 rows in set (0.07 sec)

SHOW SHARDING TABLE NODES

mysql> SHOW SHARDING TABLE NODES;
+---------+----------------------------------------------------------------+
| name    | nodes                                                          |
+---------+----------------------------------------------------------------+
| t_order | ds_0.t_order_0, ds_1.t_order_1, ds_0.t_order_2, ds_1.t_order_3 |
+---------+----------------------------------------------------------------+
1 row in set (0.02 sec)

Sharding Binding Table Rule

mysql> SHOW SHARDING BINDING TABLE RULES;
+----------------------+
| 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)

Sharding Scaling Rule

mysql> SHOW SHARDING SCALING RULES;
+------------------+----------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------+--------------------------------------------------------+-------------------------------------------------------------------------+-----------------------------------------------------+
| name             | input                                                                                  | output                                                                                   | stream_channel                                         | completion_detector                                                     | data_consistency_checker                            |
+------------------+----------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------+--------------------------------------------------------+-------------------------------------------------------------------------+-----------------------------------------------------+
| sharding_scaling | {"workerThread":40,"batchSize":1000} | {"workerThread":40,"batchSize":1000} | {"type":"MEMORY","props":{"block-queue-size":"10000"}} | {"type":"IDLE","props":{"incremental-task-idle-minute-threshold":"30"}} | {"type":"DATA_MATCH","props":{"chunk-size":"1000"}} |
+------------------+----------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------+--------------------------------------------------------+-------------------------------------------------------------------------+-----------------------------------------------------+
1 row in set (0.00 sec)