Work with disk-storage information

• Extent size:

  An allocation extent is a collection of contiguous bytes within an sbspace that the database server allocates to a smart large object at one time. The database server performs storage allocations for smart large objects in increments of the extent size.

  You can specify an extent size by calling the ifxLobDescriptor.setExtSize() method.

• Next-extent size:

  The database server tries to allocate an extent as a single, contiguous region in a chunk. However, if no single extent is large enough, the database server must use multiple extents as necessary to satisfy the current write request. After the initial extent fills, the database server attempts to allocate another extent of contiguous disk space. This process is called next-extent allocation.

For more information about extents, see the topics on disk structure and storage in the HCL OneDB Administrator's Guide.

• Estimated number of bytes in a new smart large object
• Maximum number of bytes to which the smart large object can grow

To specify sizing information, you can use the setMaxBytes() and setEstBytes() methods in the ifxLobDescriptor class.

If you know the size of the smart large object, specify this size using the setEstBytes() method. This is the best way to set the extent size because the database server can allocate the entire smart large object as one extent.

The name of the sbspace identifies the location at which to store the smart large object. To set this name, you can use the vifxLobDescriptor.setSbSpace() method.