Oracle table partition

oracle Table partitioning

1. Create table partition

1.1 New table

• New tables can be created directly

1.2 Create partitions for old tables

• Online redefining function （ Baidu ）

• Directly establish

  • Back up the old table first （ best ）

  • Query the index of the old table

  • Create partitions （ With hash Zoning as an example ）

    • --  Create partitions 
      create table IDX_MAKT_QUOT_PARTITION
      partition by hash(PROD_CD)
      (
      	partition p1 ,
      	partition p2 ,
      	partition p3 ,
      	partition p4
      )
      as select * from IDX_MAKT_QUOT
      

  • View partition data

    • --  View the data of the corresponding partition 
      select count(*) from IDX_MAKT_QUOT_PARTITION partition(p2);
      select PROD_CD from IDX_MAKT_QUOT_PARTITION partition(p3) GROUP BY PROD_CD HAVING count(PROD_CD) >1 ;
      

  • View the partition table information

    • select * from user_tab_partitions;
      select * from DBA_PART_TABLES a where a.owner=upper('otc') and a.table_name=upper('IDX_MAKT_QUOT_PARTITION');
      

  • Enable update operations to span table partitions ( It's best that the partition field doesn't change )

    • --  Enable update operations to span table partitions   The default partition table is not allowed for partition fields update Operation of the , Report errors ——ORA-14402:  Updating the partition keyword column causes the partition to change 
      alter table IDX_MAKT_QUOT_PARTITION enable row movement;
      --  Turn off row migration 
      alter table IDX_MAKT_QUOT_PARTITION disable row movement;
      

  • More partition maintenance references  https://blog.csdn.net/woailyoo0000/article/details/78836474

2. Create index

• Create index ( Local index )

  • create index IDX_MAKT_QUOT_PARTITION_INDEX on IDX_MAKT_QUOT_PARTITION(PROD_CD)
    local
    (
    partition p1 ,
    partition p2 ,
    partition p3 ,
    partition p4
    )
    

• View index information

  • --  View index information , View partition information （ Include the number of rows per partition ）
    select * from dba_ind_partitions where index_name='IDX_MAKT_QUOT_PARTITION_INDEX'
    select * from user_indexes where index_name='IDX_MAKT_QUOT_PARTITION_INDEX';
    

• More reference  https://www.cnblogs.com/xcnblog3035/p/5266894.html https://blog.csdn.net/wonderful_life_mrchi/article/details/77062861https://blog.csdn.net/xujinyang/article/details/710955

3. Delete partition table

• Delete directly

  • ALTER TABLE IDX_MAKT_QUOT_PARTITION DROP PARTITION p1;
    

• If you accidentally delete the table first , You can also see the partition table by viewing the partition information , But the table name is random

  • --  Delete the table in the recycle bin 
    ALTER TABLE IDX_MAKT_QUOT_PARTITION DROP PARTITION p1;
    

• More reference  https://blog.csdn.net/shangzhiliang_2008/article/details/46728279 https://blog.csdn.net/smilecjw/article/details/78658984