This topic describes the incompatibilities between an Oracle database and an Oracle-compatible tenant of OceanBase Database in changing the lengths of columns that have different constraints.
Change the length of a PRIMARY KEY column
The following table describes the incompatibilities between an Oracle database and an Oracle-compatible tenant of OceanBase Database in changing the length of a PRIMARY KEY column by using the ALTER TABLE table_name MODIFY DDL statement.
| Column type in Oracle database | Allowed operation | Column type in Oracle-compatible tenant of OceanBase Database | Allowed operation |
|---|---|---|---|
| INTEGER | - | NUMBER(38,0) | - |
| INT | - | NUMBER(38,0) | - |
| SMALLINT | - | NUMBER(38,0) | - |
| BINARY_FLOAT | - | BINARY_FLOAT | - |
| BINARY_DOUBLE | - | BINARY_DOUBLE | - |
| DECIMAL | Increase and decrease the length | NUMBER | Increase the length |
| DEC | Increase and decrease the length | NUMBER | Increase the length |
| NUMERIC | Increase and decrease the length | NUMBER | Increase the length |
| REAL | Increase and decrease the length | NUMBER | Increase the length |
| FLOAT | Increase and decrease the length | FLOAT | Increase the length |
| NUMBER | Increase and decrease the length | NUMBER | Increase the length |
| NCHAR | Increase and decrease the length | NCHAR | Increase the length |
| CHAR | Increase and decrease the length | CHAR | Increase the length |
| CHARACTER | Increase and decrease the length | CHAR | Increase the length |
| NVARCHAR2 | Increase and decrease the length | NVARCHAR2 | Increase the length |
| VARCHAR2 | Increase and decrease the length | VARCHAR2 | Increase the length |
| VARCHAR | Increase and decrease the length | VARCHAR2 | Increase the length |
| RAW | Increase and decrease the length | RAW | Increase the length |
| ROWID | - | ROWID | - |
| UROWID | - | UROWID | - |
| TIMESTAMP | Increase and decrease the length | TIMESTAMP | Increase the length |
| TIMESTAMP WITH LOCAL TIME ZONE | Increase and decrease the length | TIMESTAMP WITH LOCAL TIME ZONE | Increase and decrease the length |
| DATE | - | DATE | - |
| INTERVAL YEAR TO MONTH | Increase and decrease the length | INTERVAL YEAR TO MONTH | Increase and decrease the length |
| INTERVAL DAY TO SECOND | Increase and decrease the length | INTERVAL DAY TO SECOND | Increase and decrease the length |
Change the length of a UNIQUE KEY column
The incompatibilities between the Oracle database and the Oracle-compatible tenant of OceanBase Database in changing the length of a UNIQUE KEY column by using the ALTER TABLE table_name MODIFY DDL statement are the same as that in changing the length of a PRIMARY KEY column.
Change the length of a column with a CHECK constraint
The following table describes the incompatibilities between an Oracle database and an Oracle-compatible tenant of OceanBase Database in changing the length of a column that has a CHECK constraint by using the ALTER TABLE table_name MODIFY DDL statement.
| Column type in Oracle database | Allowed operation | Column type in Oracle-compatible tenant of OceanBase Database | Allowed operation |
|---|---|---|---|
| INTEGER | - | NUMBER(38,0) | - |
| INT | - | NUMBER(38,0) | - |
| SMALLINT | - | NUMBER(38,0) | - |
| BINARY_FLOAT | - | BINARY_FLOAT | - |
| BINARY_DOUBLE | - | BINARY_DOUBLE | - |
| DECIMAL | Increase and decrease the length | NUMBER | - |
| DEC | Increase and decrease the length | NUMBER | - |
| NUMERIC | Increase and decrease the length | NUMBER | - |
| REAL | Increase and decrease the length | NUMBER | - |
| FLOAT | Increase and decrease the length | FLOAT | - |
| NUMBER | Increase and decrease the length | NUMBER | - |
| NCHAR | Increase and decrease the length | NCHAR | - |
| CHAR | Increase and decrease the length | CHAR | - |
| CHARACTER | Increase and decrease the length | CHAR | - |
| NVARCHAR2 | Increase and decrease the length | NVARCHAR2 | - |
| VARCHAR2 | Increase and decrease the length | VARCHAR2 | - |
| VARCHAR | Increase and decrease the length | VARCHAR2 | - |
| RAW | Increase and decrease the length | RAW | - |
| ROWID | - | ROWID | - |
| UROWID | - | UROWID | - |
| TIMESTAMP | Increase and decrease the length | TIMESTAMP | - |
| TIMESTAMP WITH LOCAL TIME ZONE | Increase and decrease the length | TIMESTAMP WITH LOCAL TIME ZONE | - |
| DATE | - | DATE | - |
| INTERVAL YEAR TO MONTH | Increase and decrease the length | INTERVAL YEAR TO MONTH | - |
| INTERVAL DAY TO SECOND | Increase and decrease the length | INTERVAL DAY TO SECOND | - |
Change the length of a FOREIGN KEY column
The incompatibilities between the Oracle database and the Oracle-compatible tenant of OceanBase Database in changing the length of a FOREIGN KEY column by using the ALTER TABLE table_name MODIFY DDL statement are the same as that in changing the length of a PRIMARY KEY column.
