16.6 Determining the size of a user LOB RDAREA

The following formula is used to determine the size of a user LOB RDAREA.

Formula
Size of user LOB RDAREA (bytes)
= ( total number of pages in the directory page part + total number of pages in the data page part) x 8,192#
#: Page length of user LOB RDAREA.
Organization of this section
(1) Total number of pages in the directory page part
(2) Total number of pages in the data page part

(1) Total number of pages in the directory page part

Formula
Total number of pages in the directory page part
a
= [Figure]Si[Figure] 64,000[Figure] x 96 + 7 + 3 x (a - 1)
i=1
a: Number of HiRDB files that constitute the user LOB RDAREA
Si: Number of segments for each HiRDB file specified with the create rdarea statement of the database initialization utility (pdinit) or database structure modification utility (pdmod)

(2) Total number of pages in the data page part

Formula
Total number of pages in the data page part
b
= [Figure](Cj + 1,024) [Figure] 8,192[Figure]
j = 1
b: Total number of rows in LOB columns
Count rows with a data length of 0, but do not count rows with the NULL value.
Cj: Length of each BLOB data (bytes)