SET_TABLEGROUP_BALANCE_WEIGHT

The SET_TABLEGROUP_BALANCE_WEIGHT subprogram sets the weight of a Sharding = 'NONE' table group.

Limitations

In OceanBase Database V4.4.2:

• For versions earlier than V4.4.2 BP1, you can set the weight of a table group only if the Sharding attribute is NONE.

• For V4.4.2 BP1 and later, you can set the weight of a table group only for SHARDING = 'NONE' combined with SCOPE = 'SERVER' or SHARDING = 'NONE' combined with SCOPE = 'ZONE'. You cannot set the weight for SHARDING = 'NONE' combined with SCOPE = 'CLUSTER'.

Syntax

DBMS_BALANCE.SET_TABLEGROUP_BALANCE_WEIGHT(
    weight                INT,
    tablegroup_name       VARCHAR(65535)
    ); 

Parameters

Considerations

• When enable_database_sharding_none = true, the default table group created with a new database has weight 1. Other SHARDING = 'NONE' table groups that have never had a weight set default to 0 and do not participate in weight balancing.

• For a table group that has a weight, table-level and partition-level weights in that table group have no effect.

• We recommend using at most three weight tiers:

  • High weight = 100% * total number of SHARDING = 'NONE' table groups
  • Medium weight = 50% * total number of SHARDING = 'NONE' table groups
  • Low weight = 1

Examples

• In the sys tenant, call this subprogram to set the weight of the TG_TD_test table group in the mysql tenant to 10.

  obclient> CALL DBMS_BALANCE.SET_TABLEGROUP_BALANCE_WEIGHT(10, 'TG_TD_test') TENANT = 'mysql';
  

• In a user tenant, call this subprogram to set the weight of the TG_TD_test table group in that tenant to 10.

  obclient> CALL DBMS_BALANCE.SET_TABLEGROUP_BALANCE_WEIGHT(10, 'TG_TD_test');
  

References

• For information about deleting the weights of Sharding = 'NONE' table groups, see CLEAR_TABLEGROUP_BALANCE_WEIGHT.
• For information about querying the weights of different table groups, see oceanbase.CDB_OB_DATABASES or oceanbase.DBA_OB_DATABASES.
• For information about whether to enable auto-aggregation for user tables when creating a database, see enable_database_sharding_none.