Overview

Large objects (LOBs) store large unstructured data such as literals, images, videos, and spatial data. LOBs include binary large objects (BLOBs) and character large objects (CLOBs). This topic describes the LOB data types supported by OceanBase Database and the corresponding limitations.

LOB data types

The following table describes the LOB data types supported by OceanBase Database.

Limitations for using LOB columns

LOB columns are subject to the following limitations:

• Do not specify a LOB column as a primary key column.

• The following data structures are only temporary instances and cannot be stored in database tables:

  • VARRAY of any LOB type

  • Any VARRAY that contains a LOB type, such as an object type with the LOB attribute

  • ANYDATA of any LOB type

  • Any ANYDATA that contains a LOB type

• Do not specify a LOB column in the ORDER BY clause or GROUP BY clause in a query.

• Do not specify a LOB column in a join or a SELECT...DISTINCT or SELECT...UNIQUE statement.

• When you create a AFTER UPDATE DML trigger, do not specify a LOB column in a UPDATE clause.

• Do not specify a LOB column as a part of an index key.