16.1.1 Calculating the size of a user RDAREA

Organization of this subsection
(1) Formula for calculating the size of a user RDAREA
(2) Formula for calculating the total number of pages in a user RDAREA

(1) Formula for calculating the size of a user RDAREA

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

Formula
Size of user RDAREA (bytes)
= Page length of the user RDAREA#1 x total number of pages in the user RDAREA#2
#1: This is the page length specified in the create rdarea statement for the database initialization utility or database structure modification utility.
#2: See (2) as follows.

(2) Formula for calculating the total number of pages in a user RDAREA

The following formula is used to calculate the total number of pages in a user RDAREA.

Total number of pages in a user RDAREA (pages)
= total number of pages in the directory page part + total number of pages in the data page part
(a) Formula for calculating the total number of pages in the directory page part
Total number of pages in the directory page part (pages) =
6 x (n + 1) + [Figure]20,480 [Figure] P[Figure] x 2
n
+ [Figure]{[Figure]di[Figure] b[Figure] + [Figure]di[Figure] f[Figure]}
i=1
n: Number of HiRDB files that constitute the user RDAREA
P: Page length of the user RDAREA (bytes)
b: [Figure](P - 20) [Figure] ([Figure]S[Figure] 32[Figure] x 8 + 56)[Figure]
f: [Figure](125 x P) [Figure] (16 x b)[Figure] x b
di: 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)
S: Number of pages for one segment (segment size) specified with the create rdarea statement of the database initialization utility (pdinit) or database structure modification utility (pdmod)
(b) Formula for calculating the total number of pages in the data page part
Total number of pages in the data page part (pages) =
e
[Figure]{[Figure]([Figure]i[Figure] S)[Figure] x S}
i=1
e
+ [Figure]{[Figure]([Figure]i[Figure] S)[Figure] x S}
i=1
k
+ [Figure]{[Figure](([Figure]i + 1) [Figure] S[Figure] x S}
i=1
e: Total number of pages stored in the user RDAREA
k: Total number of indexes stored in the user RDAREA
S: Number of pages for one segment (segment size) specified with the create rdarea statement of the database initialization utility (pdinit) or database structure modification utility (pdmod)
[Figure]i: Number of pages required to store a column other than BINARY columns defined as branching in each table
See 16.1.2 Calculating the number of table storage pages.
[Figure]i: Number of pages required to store BINARY columns defined as branching in each table
See 16.1.2 Calculating the number of table storage pages.
[Figure]i: Number of pages required to store each index
See 16.1.3 Calculating the number of index storage pages.