16.7 Determining the size of the registry RDAREA

The following formula is used to determine the size of the registry RDAREA.

Formula
Registry RDAREA size (bytes)
= registry RDAREA page length# x total number of registry RDAREA pages x 1.3
#
This is the page length specified by the create rdarea statement of the registry facility initialization utility (pdreginit).
Finding the total number of registry RDAREA pages
Total number of registry RDAREA pages (pages)
a
= [Figure]{[Figure]Si[Figure] d[Figure] + [Figure]Si[Figure] e[Figure] + 6 x (a + 1) + 2 x[Figure]20,480 [Figure] b[Figure]
i=1
+ number of pages storing registry management tables + number of pages storing indexes of registry management table
a: Number of HiRDB files that constitute the registry RDAREA
b: Page length of the registry RDAREA (bytes)
c: Segment size specified by the create rdarea statement of the registry facility initialization utility (pdreginit)
d: [Figure](b - 20) [Figure] {([Figure]c[Figure] 32[Figure] x 8) + 56}[Figure]
e: [Figure](125 x b) [Figure] (16 x d)[Figure] x d
Si: Number of segments of each HiRDB file specified by the create rdarea statement of the registry facility initialization utility (pdreginit)

Each table or index is allocated in segments. The value obtained for each table or index is rounded up in segments.

Organization of this section
(1) Number of pages storing registry management tables
(2) Number of pages storing registry management table indexes

(1) Number of pages storing registry management tables

Formula
[Figure]
a: Number of contexts for registry management tables
b: Page length of the registry management table
c: Length of registry context names
d: Length of access passwords
e: Number of registry management table key values (number of key names registered in the registry management table)
f: Length of registry key name
g: Length of registry key value (add when the registry key value length is 32,000 bytes or less)

(2) Number of pages storing registry management table indexes

Formula
Number of pages storing registry management table indexes (pages)
= number of pages storing indexes of SQL_REGISTRY_CONTEXT tables
+ number of pages storing indexes of SQL_REGISTRY_KEY tables

For details about the number of pages storing indexes of SQL_REGISTRY_CONTEXT tables and the number of pages storing indexes of SQL_REGISTRY_KEY tables, see 16.1.3 Calculating the number of index storage pages. However, calculate the formula using 30% as the percentage of unused areas specified in the CREATE INDEX statement.

The following table lists the values used in the formula for the number of pages storing indexes.

Values used in formula for number of pages storing registry RDAREA indexes
Name of tableTypeKey lengthKey typeAverage duplication level
SQL_REGISTRY_CONTEXT72a + 1Number of context names (number of registry management table contexts)1
SQL_REGISTRY_KEY73f + 6Number of key values (number of registry management table key values)1
a: Length of registry contexts
f: Length of registry key names