16 December, 2018

Partioning -- 13a : Relocating a Partition

When you want to / need to move a Partition to a different Tablespace (e.g. as part of a LifeCycle Management Policy), you may need downtime to relocate the Partition.  However, version 12cRelease1 allows Online Relocation of a Partition.

Let's say I have a SALES_DATA table and I need to move the Year 2016 data to a tablespace with datafiles on "cheaper" (lesss-performant) storage :

SQL> select partition_name, tablespace_name
  2  from user_tab_partitions
  3  where table_name = 'SALES_DATA'
  4  order by partition_position
  5  /

PARTITION_NAME                 TABLESPACE_NAME
------------------------------ ------------------------------
P_2016                         TBS_YEAR_2016
P_2017                         TBS_YEAR_2017
P_2018                         TBS_YEAR_2018
P_2019                         TBS_YEAR_2019
P_2020                         TBS_YEAR_2020
P_MAXVALUE                     USERS

6 rows selected.

SQL> 
SQL> select index_name, tablespace_name, status
  2  from user_indexes
  3  where table_name = 'SALES_DATA'
  4  /

INDEX_NAME                     TABLESPACE_NAME                STATUS
------------------------------ ------------------------------ --------
SYS_C0017514                   HEMANT                         VALID
SALES_DATA_LCL_NDX_1                                          N/A
SALES_DATA_LCL_NDX_2                                          N/A

SQL>
SQL> l
  1  select index_name, partition_name, tablespace_name, status
  2  from user_ind_partitions
  3  where index_name in
  4  (select index_name
  5   from user_indexes
  6   where table_name = 'SALES_DATA')
  7* order by index_name, partition_position
SQL> /

INDEX_NAME                     PARTITION_NA TABLESPACE_NAM STATUS
------------------------------ ------------ -------------- --------
SALES_DATA_LCL_NDX_1           P_2016       TBS_YEAR_2016  USABLE
SALES_DATA_LCL_NDX_1           P_2017       TBS_YEAR_2017  USABLE
SALES_DATA_LCL_NDX_1           P_2018       TBS_YEAR_2018  USABLE
SALES_DATA_LCL_NDX_1           P_2019       TBS_YEAR_2019  USABLE
SALES_DATA_LCL_NDX_1           P_2020       TBS_YEAR_2020  USABLE
SALES_DATA_LCL_NDX_1           P_MAXVALUE   USERS          USABLE
SALES_DATA_LCL_NDX_2           P_2016       TBS_YEAR_2016  USABLE
SALES_DATA_LCL_NDX_2           P_2017       TBS_YEAR_2017  USABLE
SALES_DATA_LCL_NDX_2           P_2018       TBS_YEAR_2018  USABLE
SALES_DATA_LCL_NDX_2           P_2019       TBS_YEAR_2019  USABLE
SALES_DATA_LCL_NDX_2           P_2020       TBS_YEAR_2020  USABLE
SALES_DATA_LCL_NDX_2           P_MAXVALUE   USERS          USABLE

12 rows selected.

SQL> 


I then want to move the Year 2016 data to the Tablespace ARCHIVE_SALES_DATA :

SQL> alter table SALES_DATA
  2  move partition P_2016
  3  tablespace ARCHIVE_SALES_DATA
  4  /

Table altered.

SQL> 
SQL> select partition_name, tablespace_name
  2  from user_tab_partitions
  3  where table_name = 'SALES_DATA'
  4  order by partition_position
  5  /

PARTITION_NA TABLESPACE_NAME
------------ ------------------
P_2016       ARCHIVE_SALES_DATA
P_2017       TBS_YEAR_2017
P_2018       TBS_YEAR_2018
P_2019       TBS_YEAR_2019
P_2020       TBS_YEAR_2020
P_MAXVALUE    USERS

6 rows selected.

SQL> 
SQL> select index_name, tablespace_name, partitioned, status
  2  from user_indexes
  3  where table_name = 'SALES_DATA'
  4  order by index_name
  5  /

INDEX_NAME                     TABLESPACE_NAME    PAR STATUS
------------------------------ ------------------ --- --------
SALES_DATA_LCL_NDX_1                              YES N/A
SALES_DATA_LCL_NDX_2                              YES N/A
SYS_C0017514                   HEMANT             NO  UNUSABLE

SQL> alter index SYS_C0017514 rebuild ;   

Index altered.

SQL> select index_name, tablespace_name, partitioned, status
  2  from user_indexes
  3  where table_name = 'SALES_DATA'
  4  order by index_name
  5  /

INDEX_NAME                     TABLESPACE_NAME    PAR STATUS
------------------------------ ------------------ --- --------
SALES_DATA_LCL_NDX_1                              YES N/A
SALES_DATA_LCL_NDX_2                              YES N/A
SYS_C0017514                   HEMANT             NO  VALID

SQL> 
SQL> l
  1  select index_name, partition_name, tablespace_name, status
  2  from user_ind_partitions
  3  where index_name in
  4  (select index_name
  5  from user_indexes
  6  where table_name = 'SALES_DATA')
  7* order by index_name, partition_position
SQL> /

INDEX_NAME                     PARTITION_NA TABLESPACE_NAME    STATUS
------------------------------ ------------ ------------------ --------
SALES_DATA_LCL_NDX_1           P_2016       TBS_YEAR_2016      UNUSABLE
SALES_DATA_LCL_NDX_1           P_2017       TBS_YEAR_2017      USABLE
SALES_DATA_LCL_NDX_1           P_2018       TBS_YEAR_2018      USABLE
SALES_DATA_LCL_NDX_1           P_2019       TBS_YEAR_2019      USABLE
SALES_DATA_LCL_NDX_1           P_2020       TBS_YEAR_2020      USABLE
SALES_DATA_LCL_NDX_1           P_MAXVALUE   USERS              USABLE
SALES_DATA_LCL_NDX_2           P_2016       TBS_YEAR_2016      UNUSABLE
SALES_DATA_LCL_NDX_2           P_2017       TBS_YEAR_2017      USABLE
SALES_DATA_LCL_NDX_2           P_2018       TBS_YEAR_2018      USABLE
SALES_DATA_LCL_NDX_2           P_2019       TBS_YEAR_2019      USABLE
SALES_DATA_LCL_NDX_2           P_2020       TBS_YEAR_2020      USABLE
SALES_DATA_LCL_NDX_2           P_MAXVALUE   USERS              USABLE

12 rows selected.

SQL> 
SQL> alter index SALES_DATA_LCL_NDX_1
  2  rebuild partition P_2016
  3  tablespace ARCHIVE_SALES_DATA
  4  /

Index altered.

SQL> 
SQL> alter index SALES_DATA_LCL_NDX_2
  2  rebuild partition P_2016
  3  tablespace ARCHIVE_SALES_DATA
  4  /

Index altered.

SQL> 
SQL> l
  1  select index_name, partition_name, tablespace_name, status
  2  from user_ind_partitions
  3  where index_name in
  4  (select index_name
  5  from user_indexes
  6  where table_name = 'SALES_DATA')
  7* order by index_name, partition_position
SQL> /

INDEX_NAME                     PARTITION_NA TABLESPACE_NAME    STATUS
------------------------------ ------------ ------------------ --------
SALES_DATA_LCL_NDX_1           P_2016       ARCHIVE_SALES_DATA USABLE
SALES_DATA_LCL_NDX_1           P_2017       TBS_YEAR_2017      USABLE
SALES_DATA_LCL_NDX_1           P_2018       TBS_YEAR_2018      USABLE
SALES_DATA_LCL_NDX_1           P_2019       TBS_YEAR_2019      USABLE
SALES_DATA_LCL_NDX_1           P_2020       TBS_YEAR_2020      USABLE
SALES_DATA_LCL_NDX_1           P_MAXVALUE   USERS              USABLE
SALES_DATA_LCL_NDX_2           P_2016       ARCHIVE_SALES_DATA USABLE
SALES_DATA_LCL_NDX_2           P_2017       TBS_YEAR_2017      USABLE
SALES_DATA_LCL_NDX_2           P_2018       TBS_YEAR_2018      USABLE
SALES_DATA_LCL_NDX_2           P_2019       TBS_YEAR_2019      USABLE
SALES_DATA_LCL_NDX_2           P_2020       TBS_YEAR_2020      USABLE
SALES_DATA_LCL_NDX_2           P_MAXVALUE   USERS              USABLE

12 rows selected.

SQL> 


When I relocated the P_2016 Partition (to the ARCHIVE_SALES_DATA Tablespace), the ROWIDs for rows in that Partition changed.  So the Non-Partitioned Index SYS_C0017514 and the corresponding Local Partitions of the two Partitioned Indexes became "UNUSABLE".  These had to be rebuilt. Alternatively, I could have added the UPDATE INDEXES clause to to the ALTER TABLE ... MOVE PARTITION .. statement to reset the Indexes to Usable but this would not have relocated the Local Partitions for those two Indexes to the new Tablespace.

Note that for Table Partitions, the MOVE clause relocates the Partition but for Index Partition the REBUILD clause is used to relocate (as well as make Usable) the Partition.

I would encourage you to view documentation and examples of the MOVE ONLINE facility in 12c to relocate a Table Partition without downtime.


1 comment:

Foued said...

Interesting post , thank you for the share.

Preview Popular Posts