Overview

Large objects (LOBs) store large unstructured data such as texts, 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 V4.3.3 and the corresponding limitations.

LOB data types

The following table describes the LOB data types supported by OceanBase Database V4.3.3.

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:

  • Any VARRAY object of a LOB type

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

  • Any ANYDATA object of a LOB type

  • Any ANYDATA object that contains a LOB type

• Do not specify a LOB column in the ORDER BY 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 an UPDATE OF clause.

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