Overview

This topic describes the conversion scope of ALTER TABLE DDL operations during data migration from an Oracle database to the Oracle compatible mode of OceanBase Database.

Syntax

ALTER TABLE [ schema. ] table
[ memoptimize_read_clause ]
[ memoptimize_write_clause ]
[ alter_table_properties
   | column_clauses
   | constraint_clauses
   | alter_table_partitioning
   | alter_external_table
   | move_table_clause
   | modify_to_partitioned
   | modify_opaque_type
   | immutable_table_clauses
   | blockchain_table_clauses
  ]
[ enable_disable_clause
   | enable_disable_other_clause
  ] ...
;

memoptimize_read_clause:
[ { (MEMOPTIMIZE FOR READ) | (NO MEMOPTIMIZE FOR READ) } ]

memoptimize_write_clause:
[ { (MEMOPTIMIZE FOR WRITE) | (NO MEMOPTIMIZE FOR WRITE) } ]

alter_external_table:
{ add_column_clause
| modify_column_clauses
| drop_column_clause
| parallel_clause
| external_table_data_props
| REJECT LIMIT { integer | UNLIMITED }
| PROJECT COLUMN { ALL | REFERENCED }
}
  [ add_column_clause
  | modify_column_clauses
  | drop_column_clause
  | parallel_clause
  | external_table_data_props
  | REJECT LIMIT { integer | UNLIMITED }
  | PROJECT COLUMN { ALL | REFERENCED }
  ]...

move_table_clause:
MOVE
   [ filter_condition ]
   [ ONLINE ]
   [ segment_attributes_clause ]
   [ table_compression ]
   [ index_org_table_clause ]
   [ { LOB_storage_clause | varray_col_properties }... ]
   [ parallel_clause ]
   [ allow_disallow_clustering ]
   [ UPDATE INDEXES
     [ ( index { segment_attributes_clause
               | update_index_partition }
         [, index { segment_attributes_clause
                  | update_index_partition } ]...
       )
     ]
   ]

modify_to_partitioned:
MODIFY table_partitioning_clauses
  [ filter_condition ]
  [ ONLINE ]
  [ UPDATE INDEXES [ ( index { local_partitioned_index | global_partitioned_index | GLOBAL }
                     [, index { local_partitioned_index | global_partitioned_index | GLOBAL } ]... )
                   ]
  ]

modify_opaque_type:
MODIFY OPAQUE TYPE anydata_column
STORE ( type_name [, type_name ]... ) UNPACKED

immutable_table_clauses:
[ immutable_table_no_drop_clause ]
    [ immutable_table_no_delete_clause ]

blockchain_table_clauses:
 blockchain_drop_table_clause 
     blockchain_row_retention_clause 
     blockchain_hash_and_data_format_clause

enable_disable_clause:
{ ENABLE | DISABLE }
[ VALIDATE | NOVALIDATE ]
{ UNIQUE (column [, column ]...)
| PRIMARY KEY
| CONSTRAINT constraint_name
}
[ using_index_clause ]
[ exceptions_clause ]
[ CASCADE ]
[ { KEEP | DROP } INDEX ]

enable_disable_other_clause:
{ ENABLE | DISABLE }
   { TABLE LOCK | ALL TRIGGERS | CONTAINER_MAP | CONTAINERS_DEFAULT }

Supported operations

• Modifying, dropping, and adding table attributes by using the alter_table_properties clause is supported. For more information, see Modify, drop, and add table attributes.

• Modifying, dropping, and adding column attributes by using the column_clauses clause is supported. For more information, see Modify, drop, and add column attributes.

• Modifying, dropping, and adding constraints by using the constraint_clauses clause is supported. For more information, see Modify, drop, and add constraints.

• Modifying, dropping, and adding partitions by using the alter_table_partitioning clause is supported. For more information, see Modify, drop, and add partitions.

Unsupported operations

• Modifying the characteristics of external tables by using the alter_external_table clause is not supported. An error will be returned when you perform this operation.

• Relocating the data of a non-partitioned table or a partition of a partitioned table to a new segment by using the move_table_clause clause is not supported. An error will be returned when you perform this operation.

• Changing a non-partitioned table or a partitioned table into a partitioned or composite partitioned table with specified characteristics by using the modify_to_partitioned clause is not supported. An error will be returned when you perform this operation.

• Specifying the database to store an abstract data type or enable decompressed storage by using the modify_opaque_type clause is not supported. An error will be returned when you perform this operation.

• Modifying the definition of an immutable table by using the immutable_table_clauses clause is not supported. An error will be returned when you perform this operation.

• Modifying the definition of a blockchain table by using the blockchain_table_clauses clause is not supported. An error will be returned when you perform this operation.

• Improving the query performance for high-frequency data by using the memoptimize_read_clause clause is not supported. An error will be returned when you perform this operation.

• Enabling fast write by using the memoptimize_write_clause clause is not supported. An error will be returned when you perform this operation.

• Defining how the database uses constraints by using the enable_disable_clause clause is not supported. An error will be returned when you perform this operation.

• Enabling or disabling all triggers associated with the table, table locks, queries on the mapped CONTAINER MAP table, and the table in the CONTAINERS by using the enable_disable_other_clause clause is not supported. An error will be returned when you perform this operation.