17.1.1 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 RDAREA1[Figure] total number of pages in the user RDAREA2
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 =

 a
 [Figure] { [Figure] Si [Figure] f [Figure] + [Figure] Si [Figure] g [Figure]}
 i=1
  c
 + [Figure]{ [Figure] Ti [Figure] e [Figure] [Figure] e}
  i=1
  d
+ [Figure]{ [Figure](Ii + 1) [Figure] e [Figure] [Figure] e} + 6 [Figure](a + 1) + 2 [Figure] [Figure] 20480 [Figure] b [Figure]
  i=1

a: Number of HiRDB files constituting the user RDAREA
b: Page length of the user RDAREA (bytes)
c: Total number of tables in the user RDAREA
d: Total number of indexes to be stored in the user RDAREA
e: Segment size specified in the create rdarea statement for the database initialization utility (pdinit) or database structure modification utility (pdmod)
f: [Figure]{b - 20} [Figure] {([Figure] e[Figure] 32 [Figure][Figure] 8) + 56}[Figure]
g: [Figure] (125 [Figure] b) [Figure] (16 [Figure] f) [Figure][Figure] f
Si: Number of segments in each HiRDB file that is specified in the create rdarea statement for the database initialization utility (pdinit) or database structure modification utility (pdmod)
Ti: Number of pages required to store each table (see 17.1.2 Calculating the number of table storage pages)
Ii: Number of pages required to store each index (see 17.1.3 Calculating the number of index storage pages)