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Category :
Database
Resources -> Database Administration -> Troubleshooting & Solutions
DB Version
:
Oracle 8i /
Oracle 9i
OS Details :
Sun Solaris9
Have
you hit the
ORA-14402 error while updating a
table? If you have then it is due to oracle's row movement. Row
movement is associated with partitioned and non-partitioned tables but
is primarily associated with partitioned tables. For partitioned
tables when ROW MOVEMENT is enabled users have the ability to update
partitioning key columns in such a way that a row no longer belongs in
its current partition, causing such rows to migrate to the appropriate
partition. Row movement is enabled at the table level and is disabled
by default. For example:
CREATE TABLE sales(
sale_id NUMBER NOT NULL,
sale_date DATE,
prod_id NUMBER,
qty NUMBER)
PARTITION BY RANGE(prod_id)
(PARTITION salesp1 VALUES LESS THAN(10),
PARTITION salesp2 VALUES LESS THAN(20),
PARTITION salesp3 VALUES LESS THAN(30),
PARTITION salesp4 VALUES LESS THAN(40))
Partition salesp1 above will have prod_id values upto 9 (since
partition high values are non-inclusive). If you issue an update
statement like this:
SQL> update sales set prod_id = 15 where prod_id = 5;
For the above statement to succeed, oracle has to migrate the row that
you are updating from partition salesp1 to salesp2. Under those
circumstances, it will raise this error:
ORA-14402: updating partition key column would cause a partition
change
You can overcome the above error by issuing this statement:
SQL> ALTER TABLE sales ENABLE ROW MOVEMENT;
-- You can now issue the update statement successfully
SQL> update sales set prod_id = 15 where prod_id = 5;
4 rows updated
SQL> commit;
Row movement is allowed for non-partitioned tables starting 9i. Row
movement comes in to affect for non-partitioned tables when you do
operations like table compression.
Couple of things to be beware of with row movement are (1) Oracle will
do a delete and insert in the background which can cause performance
issues and (2) The rowid for the row that went through row migration
will change which can potentially cause problems if the application
uses static rowids for data access.
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