MAJOR and MINOR

Description

This statement is used to initiate major compactions or minor compactions (freezes) in the system tenant. Manual major compactions are supported at the tenant level only. Manual minor compactions are supported at the tenant level, zone level, server level, log stream level, and partition level.

Syntax

ALTER SYSTEM merge_action;

merge_action:
      MAJOR FREEZE [tenant_list]
    | MAJOR FREEZE [tenant_list]
    | MINOR FREEZE [tenant_list | server_list | zone_list | {TENANT [=] tenant_name LS [=] ls_id} | {TENANT [=] tenant_name TABLET_ID = tablet_id}]
    | {SUSPEND | RESUME} MERGE [tenant_list]
    | CLEAR MERGE ERROR [tenant_list]

tenant_list:
    TENANT [=]  { all | all_user | all_meta } | tenant_name [, tenant_name ...]

server_list:
    SERVER [=] ('ip:port' [, 'ip:port'...])

zone_list:
    ZONE [=] ('zone_name' [, 'zone_name' ...]);

Parameter explanation

Example

Examples of major compactions

• Initiate a daily major compaction for the sys tenant.

  obclient> ALTER SYSTEM MAJOR FREEZE;
  Query OK, 0 rows affected
  

• Initiate major compactions for all user tenants (excluding the sys and meta tenants) for the sys tenant.

  obclient> ALTER SYSTEM MAJOR FREEZE TENANT = all_user;
  Query OK, 0 rows affected
  

• Initiate major compactions for all meta tenants for the sys tenant.

  obclient> ALTER SYSTEM MAJOR FREEZE TENANT = all_meta;
  Query OK, 0 rows affected
  

• Initiate major compactions for specified tenants tenant1 and tenant2 for the sys tenant.

  obclient> ALTER SYSTEM MAJOR FREEZE TENANT = tenant1,tenant2;
  Query OK, 0 rows affected
  

Examples of minor compactions

• Initiate a minor compaction for the sys tenant.

  obclient> ALTER SYSTEM MINOR FREEZE;
  Query OK, 0 rows affected
  

• Initiate minor compactions for all user tenants (excluding the sys and meta tenants) for the sys tenant.

  obclient> ALTER SYSTEM MINOR FREEZE TENANT = all_user;
  Query OK, 0 rows affected
  

• Initiate minor compactions for all meta tenants for the sys tenant.

  obclient> ALTER SYSTEM MINOR FREEZE TENANT = all_meta;
  Query OK, 0 rows affected
  

• Initiate minor compactions for specified tenants tenant1 and tenant2 for the sys tenant.

  obclient> ALTER SYSTEM MINOR FREEZE TENANT = tenant1,tenant2;
  Query OK, 0 rows affected
  

• Initiate a minor compaction for specified partitions of tenant tenant1.

  obclient> ALTER SYSTEM MINOR FREEZE tenant = tenant1 tablet_id = 1100611139453887;
  Query OK, 0 rows affected
  

• Initiate a minor compaction for a specified OBServer.

  obclient> ALTER SYSTEM MINOR FREEZE SERVER = ('10.XXX.XXX.XXX:2882');
  Query OK, 0 rows affected
  

• Initiate a minor compaction for specified log streams of a specified tenant.

  obclient> ALTER SYSTEM MINOR FREEZE tenant = t1 LS 1;
  Query OK, 0 rows affected
  

• Initiate a minor compaction for specified partitions of a specified log stream of a specified tenant.

  obclient> ALTER SYSTEM MINOR FREEZE tenant = t1 ls 1 tablet_id = 60000;
  Query OK, 0 rows affected
  

Examples of pausing and resuming daily major compactions

• Pause daily major compactions for all user tenants (excluding the sys and meta tenants) for the sys tenant.

  obclient> ALTER SYSTEM SUSPEND MERGE TENANT = all_user;
  Query OK, 0 rows affected
  

• Pause daily major compactions for specified tenants tenant1 and tenant2 for the sys tenant.

  obclient> ALTER SYSTEM SUSPEND MERGE TENANT = tenant1,tenant2;
  Query OK, 0 rows affected
  

• Pause daily major compactions for all meta tenants for the sys tenant.

  obclient> ALTER SYSTEM SUSPEND MERGE TENANT = all_meta;
  Query OK, 0 rows affected
  

• Resume daily major compactions for all user tenants (excluding the sys and meta tenants) for the sys tenant.

  obclient> ALTER SYSTEM RESUME MERGE TENANT = all_user;
  Query OK, 0 rows affected
  

• Resume daily major compactions for specified tenants tenant1 and tenant2 for the sys tenant.

  obclient> ALTER SYSTEM RESUME MERGE TENANT = tenant1,tenant2;
  Query OK, 0 rows affected
  

• Resume daily major compactions for all meta tenants for the sys tenant.

  obclient> ALTER SYSTEM RESUME MERGE TENANT = all_meta;
  Query OK, 0 rows affected
  

Examples of cleaning up error flags for major compactions

• Clean up error flags for major compactions for all user tenants (excluding the sys and meta tenants) for the sys tenant.

  obclient> ALTER SYSTEM CLEAR MERGE ERROR TENANT = all_user;
  Query OK, 0 rows affected
  

• Clean up error flags for major compactions for specified tenants tenant1 and tenant2 for the sys tenant.

  obclient> ALTER SYSTEM CLEAR MERGE ERROR TENANT = tenant1,tenant2;
  Query OK, 0 rows affected
  

• Clean up error flags for major compactions for all meta tenants for the sys tenant.

  obclient> ALTER SYSTEM CLEAR MERGE ERROR TENANT = all_meta;
  Query OK, 0 rows affected
  

Initiate a minor compaction at the partition level

1. Query the table ID of the table.

   Here is an example:

   SELECT t1.tenant_id, t2.tenant_name, t1.database_name, t1.table_id, t1.table_name, t1.tablet_id, t1.PARTITION_NAME, t1.SUBPARTITION_NAME
   FROM oceanbase.CDB_OB_TABLE_LOCATIONS t1, oceanbase.DBA_OB_TENANTS t2
   WHERE t1.tenant_id=t2.tenant_id
   AND t1.table_name = 'test_tbl1'
   AND t2.tenant_name = 'oracle001';
   

   The return result is as follows:

   +-----------+-------------+---------------+----------+------------+-----------+----------------+-------------------+
   | tenant_id | tenant_name | database_name | table_id | table_name | tablet_id | PARTITION_NAME | SUBPARTITION_NAME |
   +-----------+-------------+---------------+----------+------------+-----------+----------------+-------------------+
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200008 | P1             | SP0               |
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200009 | P1             | SP1               |
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200010 | P1             | SP2               |
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200011 | P1             | SP3               |
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200012 | P2             | SP4               |
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200013 | P2             | SP5               |
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200014 | P2             | SP6               |
   |      1004 | oracle001   | SYS           |   500011 | TEST_TBL1  |    200015 | P2             | SP7               |
   +-----------+-------------+---------------+----------+------------+-----------+----------------+-------------------+
   8 rows in set
   

   For more information about the view columns, see oceanbase.CDB_OB_TABLE_LOCATIONS.

2. Initiate a minor compaction.

   Here is an example:

   ALTER SYSTEM MINOR FREEZE TENANT = oracle001 TABLET_ID = 200008;
   

   The return result is as follows:

   Query OK, 0 rows affected
   

References

• Overview of major compactions
• Manually trigger a major compaction
• View the major compaction process
• Overview of minor compactions
• Manually trigger a minor compaction
• View minor compaction information