Limits

This topic describes the limits that you may encounter when you use features of OceanBase Developer Center (ODC) V2.2.0.

Supported database versions

ODC V2.2.0 supports the following OceanBase Database versions:

• OceanBase V1.4.x

• OceanBase V2.0.x

• OceanBase V2.1.x

• OceanBase V2.2.x

• OceanBase Database V3.1.x

The following table lists the OceanBase Database versions that support PL.

Recommended installation environment

The following table describes the recommended environment for installing the ODC client.

Account management

• ODC does not support password retrieval. If you forget your password, contact technical support.

Database connection

• Oracle connections are designed to share one session. Whether you commit or roll back a transaction, or trigger a transaction either by creating, modifying, or deleting a database object, or by executing a DDL statement, the transaction takes effect on all windows.

• In manual-commit mode, make sure to set ob_trx_idle_timeout to a value greater than the timeout value of SQL queries. Otherwise, if two SQL statements in one transaction are executed at an interval longer than the value of ob_trx_idle_timeout, the connection will be terminated. However, if ob_trx_idle_timeout is set to an excessively large value, the session cannot be released in time, resulting in unnecessary memory consumption. Therefore, you need to set this parameter to a proper value.

Workspace

• The anonymous block window is available only in Oracle mode.

• The debugging feature is unavailable when you use OBProxy to connect to an instance. Connect to the target instance directly in ODC.

• Before debugging, make sure that debugging packages, such as DBMS_DEBUG and DBMS_OUTPUT, are installed in the connected database.

• Only OBServer V2.2.70, OBServer V3.0.00, and later versions support the debugging of PL/SQL objects.

• In ODC, multiple identical connections share one single session. In ODC V2.3.2 and above, automatic committing is disabled by default for the Oracle mode. You must manually commit transactions. You can modify the value of the autocommit parameter on the Session Properties page to change this setting. For more information, see Session management.

Data import and export

• OceanBase V2.2.30 and later versions support the following character sets: UTF8, GBK, GB18030, and UTF16. Instances earlier than OceanBase V2.2.30 only support UTF8.

• In ODC V2.2.0 and later versions, to use the import and export feature, you must connect to the target instance by using OBProxy. ODC does not support import and export for direct connections.

• The maximum size of data exported in one batch in ODC cannot exceed 250 MB before compression. To export a large amount of data, use the data export tool OBDUMPER.

• The maximum size of data that you can import in ODC is 250 MB before compression. To import a large amount of data, use the data import tool OBLOADER.

• ODC allows you to run up to three import or export tasks in parallel. Subsequent tasks will wait in the queue.

• In ODC V2.4.1 and later, you can use the sys tenant account to accelerate the import and export tasks. To export objects other than tables and views, you must configure the sys tenant account.

Database objects

• An index cannot be modified after it is created.

• You can only create sequence and package objects in Oracle mode.

• The sys user has the read permission to view partition information. You need to set the sys user in Advanced Configuration during connection creation.