An sbpage is the type of page that the database
server uses to store smart large objects within an sbspace. Unlike
blobpages, sbpages are not configurable. An sbpage is the same size
as the database server page, which is usually 2 KB on UNIX™ and 4 KB on Windows™.
The unit of allocation in an sbspace is an extent, whereas the
unit of allocation in a blobspace is a blobpage. Just as with pages
in a chunk, a certain number of smart large object extents compose
a chunk in an sbspace, as the following figure illustrates. An extent
is always entirely contained in a chunk and cannot cross chunk boundaries.Figure 1. A chunk in an sbspace,
logically separated into a series of extents
Smart large objects cannot be stored in a dbspace or blobspace.
For more information, see Sbspaces,
and sbspace structure in the disk structures and storage chapter of
the Informix® Administrator's
Reference.
The database server calculates the extent size for a smart large
object from a set of heuristics, such as the number of bytes in a
write operation. For more information, see Extent sizes for sbspaces.
