Change the length of a constrained column
This topic describes the incompatibilities between an Oracle database and an Oracle 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 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 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 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 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 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 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.