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    ApsaraDB for OceanBase:Synchronize DDL operations from an Oracle tenant of OceanBase Database to an Oracle database

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    ApsaraDB for OceanBase:Synchronize DDL operations from an Oracle tenant of OceanBase Database to an Oracle database

    Last Updated:Jun 03, 2024

    Supported DDL operations

    • CREATE TABLE

      Important

      You can use it to create tables, including partitioned tables, but cannot use CREATE TABLE AS SELECT to create tables.

    • DROP TABLE

    • TRUNCATE TABLE

    • ADD PARTITION

      You can add partitions and subpartitions by using RANGE or LIST partitioning. HASH partitioning is not supported.

    • DROP PARTITION

      You can drop one or more partitions and subpartitions.

    • TRUNCATE PARTITION

      You can truncate one or more partitions and subpartitions.

    • RENAME TABLE and ALTER TABLE RENAME

    • ALTER TABLE ADD COLUMN

    • ALTER TABLE MODIFY COLUMN

      Important

      You can increase the column length, but you cannot modify the column type.

    • CREATE INDEX

    • DROP INDEX

    • Adding or dropping comments on tables or columns

    Limitations

    • Not all DDL operations are supported. If the table to synchronize involves unsupported DDL operations, the migration project may be interrupted, which causes unrecoverable data inconsistencies.

    • Frequent DDL operations on a table are not supported. Otherwise, the project may become abnormal and result in data issues, which cannot be recovered.

    • The original and new table names in the RENAME TABLE statement must be names of the tables to be synchronized.

    • If you delete an unnamed primary key, the corresponding constraint whose name starts with SYS_C in the Oracle database is deleted. If you perform inter-database data migration or synchronization, for example, from an Oracle database to an OceanBase database, the primary keys in the OceanBase database cannot be deleted because they are different from those in the Oracle database.

    • When you migrate data from an Oracle tenant of OceanBase Database to an Oracle database, you cannot perform a DDL operation that changes a table with a primary key to a table without a primary key.

      • If a table in the Oracle tenant of OceanBase Database has a primary key, all supported DDL operations can be synchronized.

      • If a table in the Oracle tenant of OceanBase Database has only a not-null unique key, a DDL operation that removes the not-null unique key is not supported.

    • A table creation DDL operation that contains the CASE WHEN INDEX clause cannot be synchronized.