MAJOR and MINOR

Purpose

This statement is used to initiate a major freeze (storage layer compaction) or minor freeze (storage layer compaction) in the system tenant. Manual compactions are supported at the tenant level only, while manual minor freezes are supported at the tenant, zone, server, log stream, and partition levels.

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' ...]);

Parameters

Examples

Example of major compactions

• The system tenant initiates a major compaction for the system tenant.

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

• The system tenant initiates a major compaction for all user tenants (excluding the system tenant and Meta tenant).

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

• The system tenant initiates a major compaction for all Meta tenants.

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

• The system tenant initiates a major compaction for the specified tenants tenant1 and tenant2.

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

Example of major dumps

• The system tenant initiates a major dump for the system tenant.

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

• The system tenant initiates a major dump for all user tenants (excluding the system tenant and Meta tenant).

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

• The system tenant initiates a major dump for all Meta tenants.

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

• The system tenant initiates a major dump for the specified tenants tenant1 and tenant2.

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

• The system tenant initiates a major dump for the specified partition under the specified tenant tenant1.

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

• The system tenant initiates a major dump for the specified OBServer node.

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

• The system tenant initiates a major dump for the specified log stream under the specified tenant tenant1.

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

• The system tenant initiates a major dump for the specified partition under the specified log stream in the specified tenant tenant1.

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

Example of pausing or resuming major compactions

• The system tenant pauses major compactions for all user tenants (excluding the system tenant and Meta tenant).

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

• The system tenant pauses major compactions for the specified tenants tenant1 and tenant2.

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

• The system tenant pauses major compactions for all Meta tenants.

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

• The system tenant resumes major compactions for all user tenants (excluding the system tenant and Meta tenant).

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

• The system tenant resumes major compactions for the specified tenants tenant1 and tenant2.

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

• The system tenant resumes major compactions for all Meta tenants.

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

Example of clearing the major compaction error flag

• The system tenant clears the major compaction error flag for all user tenants (excluding the system tenant and Meta tenant).

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

• The system tenant clears the major compaction error flag for the specified tenants tenant1 and tenant2.

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

• The system tenant clears the major compaction error flag for all Meta tenants.

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

Example of initiating a major dump at the partition level

1. Query the tablet 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 returned 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 fields, see oceanbase.CDB_OB_TABLE_LOCATIONS.

2. Initiate a major dump.

   Here is an example:

   ALTER SYSTEM MINOR FREEZE TENANT = oracle001 TABLET_ID = 200008;
   

References

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