DB2 graphic  QMF Version 8

LOB Options

Use the LOB Options to control a users ability to access, retrieve, and save data to and from tables containing large objects (LOBs).

A Large Object (LOB) is a DB2 UDB data type that houses non-traditional data such as text, multimedia, image, video, photograph, sound, or any very large data file inside a database table.

Retrieving or saving LOB data can consume a substantial amount of resources. Even just accessing a table that contains LOB data can be resource consumptive. Using the LOB Options, you can control access to tables on the database server that include LOB data.

Table 25. LOB Options
Field Description
Disable LOB columns Disable LOB data retrieval and prevent any access to tables that contain LOB data. By selecting this option, members of the resource limits group will not be able to query any table that contains LOB data.
Disable LOB data retrieval Disable LOB data retrieval but allow access to the other columns in the tables that contain LOB data. By selecting this option, members of the resource limits group can query tables that contain LOB data and QMF for Windows will return result data for all columns except those that contain LOBs.
Retrieve LOB data on demand Members of this resource limits group can query tables that contain LOB data. Result data will be returned for all columns including those that contain LOB objects.

To conserve resources, QNF for Windows stores retrieved LOB data in a file. Pointers to the LOB data objects are displayed in the query results. LOB objects can be viewed on demand by selecting the LOB object in the query results.

Retrieve LOB data automatically Members of this resource limits group can query tables that contain LOB data. Result data will be returned for all columns, including those that contain LOB objects. All result data is automatically displayed in the contents of the query results grid. This option can potentially consume a large amount of resources and time
Disable LOB data Specifies that members of this resource limits group are not allowed to save large object data (LOB) data on the database server.
Enable LOB data Specifies that members of this resource limits group are allowed to save large object data (LOB) data on the database server.
Maximum LOB column size (KB) Specify the maximum size of a LOB column, in kilobytes, up to 2G (the maximum LOB size). The default is 0, no maximum. If a member of this resource limits group attempts to query a table with LOB data that is larger than the maximum, the LOB data will not be returned for display.
LOB options can be overridden Provides users with the authority to override their default LOB options.


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timestamp Last updated: March, 2004