Note
- For OceanBase Database V4.3.x, this view was introduced in OceanBase Database V4.3.2.
- For OceanBase Database V4.2.x, this variable was introduced in OceanBase Database V4.2.3.
Purpose
The V$OB_COMPATIBILITY_CONTROL view displays all features that support product behavior compatibility control based on the released OceanBase Database versions.
Applicability
This view applies only to OceanBase Database in MySQL mode.
Columns
| Column | Type | Nullable? | Description |
|---|---|---|---|
| NAME | varchar(128) | NO | The name of the feature. |
| DESCRIPTION | varchar(4096) | NO | The description of the feature. |
| IS_ENABLE | varchar(5) | NO | Indicates whether the feature takes effect. |
| ENABLE_VERSIONS | longtext | NO | The range of OceanBase Database versions in which the feature takes effect, for example, [4.2.3.1, 4.3.0.0) or [4.3.1.0, +∞). |
Sample query
obclient [oceanbase]> SELECT * FROM oceanbase.V$OB_COMPATIBILITY_CONTROL;
The query result is as follows:
+-------------------+---------------------------------------------------------------------------------------+-----------+---------------------------------+
| NAME | DESCRIPTION | IS_ENABLE | ENABLE_VERSIONS |
+-------------------+---------------------------------------------------------------------------------------+-----------+---------------------------------+
| FUNC_REPLACE_NULL | The result of REPLACE('abd', '', null) is different in MySQL 5.7 and 8.0 | TRUE | [4.2.3.0, 4.3.0.0), [4.3.2.0, ) |
| UPD_LIMIT_OFFSET | MySQL do not support the use of OFFSET in the LIMIT clause of UPDATE/DELETE statement | TRUE | [4.2.3.0, 4.3.0.0), [4.3.2.0, ) |
| PROJECT_NULL | MySQL will rename the projection item names with pure null values to `NULL` | TRUE | [4.2.3.0, 4.3.0.0), [4.3.2.0, ) |
| VAR_NAME_LENGTH | MySQL will limit the length of user-defined variable names to within 64 characters | TRUE | [4.2.3.0, 4.3.0.0), [4.3.2.0, ) |
+-------------------+---------------------------------------------------------------------------------------+-----------+---------------------------------+
4 rows in set (0.012 sec)