A question about Row Movement

Question

I'm trying to do the Row Movement, but will it impact indexes? Will I have to re-create indexes or rebuild them?

Answer 1

On partitioned table, if you update the value of partition key of a row, the row move to the new partition and get a new ROWID. But no need to work on index after that.
Example :
Taken this partitioned table :
SQL> select table_name,partition_name,high_value from user_tab_partitions;
TABLE_NAME                     PARTITION_NAME                 HIGH_VALUE
MY_TABLE_2                     MY_TABLE_PART1                 1000
MY_TABLE_2                     MY_TABLE_PART2                 2000
MY_TABLE_2                     MY_TABLE_PARTM                 MAXVALUEOk, now taken a row of this table from part1. Note the ROWID, then see as well the explain plan and index usage :
SQL> select rowid,a.*
  2  from MY_TABLE_2 partition (MY_TABLE_PART1) a
  3* where id=258
SQL> /
ROWID                      ID DESCRIPTION
AAAO0TAAEAAACstAAA 258 DUAL
SQL> set autot traceonly explain
SQL> select rowid,a.*
  2  from MY_TABLE_2 a
  3  where id=258
  4  /
Execution Plan
Plan hash value: 2906089138
| Id  | Operation                          | Name        | Rows  | Bytes | Cost (%CPU)| Time     | Pstart| Pstop |
|   0 | SELECT STATEMENT                   |             |     1 |    21 |     2   (0)| 00:00:01 |       |       |
|   1 |  TABLE ACCESS BY GLOBAL INDEX ROWID| MY_TABLE_2  |     1 |    21 |     2   (0)| 00:00:01 | 
|*  2 |   INDEX UNIQUE SCAN                | IDX_TABLE_2 |   645 |       |     1   (0)| 00:00:01 |       |       |
Predicate Information (identified by operation id):
   2 - access("ID"=258)Ok, now move the row from the first to the second part :
SQL> set autot off
SQL> update MY_TABLE_2 set id=1500 where id=258;
update MY_TABLE_2 set id=1500 where id=258
ERROR at line 1:
ORA-14402: updating partition key column would cause a partition change
SQL> alter table MY_TABLE_2 enable row movement;
Table altered.
SQL> update MY_TABLE_2 set id=1500 where id=258;
1 row updated.Well, now, the row is no more in first, but in second part as waiting.
Note the ROWID (different of above when the row was in the first part) :
SQL> select rowid,a.*
  2  from MY_TABLE_2 partition (MY_TABLE_PART1) a
  3  where id=1500;
no rows selected
SQL> select rowid,a.*
  2  from MY_TABLE_2 partition (MY_TABLE_PART2) a
  3* where id=1500
SQL> /
ROWID                      ID DESCRIPTION
AAAO0UAAEAAAPb3AAE 1500 DUALAnd now, see the explain plan and still index usage :
SQL> set autot traceonly explain
SQL> select rowid,a.*
  2  from MY_TABLE_2 a
  3* where id=1500
SQL> /
Execution Plan
Plan hash value: 2906089138
| Id  | Operation                          | Name        | Rows  | Bytes | Cost (%CPU)| Time     | Pstart| Pstop |
|   0 | SELECT STATEMENT                   |             |     1 |    20 |     2   (0)| 00:00:01 |       |       |
|   1 |  TABLE ACCESS BY GLOBAL INDEX ROWID| MY_TABLE_2  |     1 |    20 |     2   (0)| 00:00:01 | 
|*  2 |   INDEX UNIQUE SCAN                | IDX_TABLE_2 |    74 |       |     1   (0)| 00:00:01 |       |       |
Predicate Information (identified by operation id):
   2 - access("ID"=1500)
SQL> I would advise you the reading of the article of J. Lewis : When Should You Rebuild an Index?
HTH,
Nicolas.