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)