Limitations

This topic describes the environment requirements for deploying OceanBase Developer Center (ODC) and the limitations on each feature module.

Web ODC

Client ODC

Feature support of different data source types

Limitations on using features

Permission limitations

• To avoid the impact of other operations on the MetaDB, we recommend that you use a dedicated database as the ODC MetaDB. Users require all permissions for the ODC MetaDB to access it. You can use the GRANT ALL PRIVILEGES ON odc_metadb.* TO 'user'@'host'; statement to grant a user all priviledges on the ODC MetaDB.

• To perform debugging in OceanBase Database V4.0.0 and later, make sure that you have the debugging permissions. You can execute the GRANT DEBUG CONNECT SESSION TO <user> or GRANT DEBUG ANY PROCEDURE TO <user> statement to grant the debugging permissions.

Session limitations

• ODC supports the manual commit and auto-commit modes. In manual commit mode, you must set the ob_trx_idle_timeout parameter to an appropriate value for an OceanBase data source. This is to prevent a connection from being terminated because the execution interval between two consecutive SQL statements in a transaction exceeds the value of ob_trx_idle_timeout. Generally, the value of the ob_trx_idle_timeout parameter must be greater than the timeout value of SQL queries. If you specify an excessively large value for this parameter, the memory resources occupied by this session cannot be released in a timely manner. Proceed with caution.

Limitations on SQL development

• You cannot edit a result set that contains fields of the SET or ENUM data type.

• End-to-end tracing is supported only in OceanBase Database V4.0.0 and later.

• Execution Profile is supported to provide real-time SQL diagnostics only in OceanBase Database V4.2.4 and later versions, and V4.3.3.1 and later versions.

Limitations on import and export

• The maximum size of data that can be exported in one batch in Web ODC is 2 GB before compression. To export data of a larger size, use the data export tool OBDUMPER.

• The maximum size of files that can be imported in one batch in Web ODC is 2 GB after compression. To import data of a larger size, use the data import tool OBLOADER.

• At most five concurrent import/export tasks are supported. Subsequent tasks need to wait in the queue.

• By default, files related to import/export tasks are retained for 14 days.

• In ODC V4.1.0 and later, you can configure a sys tenant account for an OceanBase data source to increase the import/export speed. When you export objects other than tables and views, a sys tenant account is no longer a must.

Limitations on change rollback

• A rollback statement can be automatically generated only for the UPDATE and DELETE statements.

• A change task is allowed to affect a maximum of 1 million rows. If the number of affected rows exceeds 1 million, a rollback statement cannot be automatically generated for this change task.

• If the table contains LOB fields, a rollback statement cannot be automatically generated.

• If the table does not have a primary or unique key when the data source is an OceanBase MySQL compatible data source or a MySQL data source, a rollback statement cannot be automatically generated.

• If the SET and WHERE clauses in an UPDATE statement are the same, a rollback statement cannot be automatically generated.

• The maximum size of a rollback script that is automatically generated is 256 MB.

Limitations on partitioning plans

• Only OceanBase MySQL compatible and OceanBase Oracle compatible data sources are supported.

• Only RANGE-partitioned tables are supported.

• When the upper bound of the last partition in a RANGE-partitioned table reaches the value specified by MAXVALUE, no partition can be created. In this case, you cannot configure partitioning strategies in the Create Partitioning Plan panel.

• The task cannot be executed when the table involved does not exist after the partition plan is issued.

Limitations on data mocking

• At most 100 million rows can be mocked at a time.

• Data mocking is not supported for a table with CHECK constraints.

• Data mocking is not supported for RANGE- or LIST-partitioned tables.

Limitations on schema comparison

• The following links are supported for schema comparison:

  • Links between MySQL-compatible tenants of OceanBase Database

  • Links between Oracle-compatible tenants of OceanBase Database

• Only table objects can be compared in terms of columns, primary keys, constraints, indexes, partitions, and attributes.

  • In terms of column attributes, only the data types, character sets, collations, comments, and default values can be compared.

  • Only partitions but not subpartitions can be compared.

  • In terms of table attributes, only the character sets, collations, and comments can be compared.

• CHECK constraints cannot be compared for MySQL-compatible tenants of OceanBase Database.

• For a MySQL-compatible tenant of OceanBase Database of a version earlier than V1.4.79, you cannot compare partition attributes if you do not have the query permissions on the sys tenant.

Limitations on data desensitization

• Data desensitization is not supported during PL execution.

• When you configure an identification rule script, Groovy supports only the Objects and String classes in Java.

• When you configure an identification rule script, Groovy closures and inherent closure functions are not supported.

Limitations on batch database changes

• You can perform batch database changes only on homogeneous data sources.