The following table lists the main memory requirements for an Adabas Vista client session.
Note:
This table is not intended to be an exhaustive list of the memory
requirements. It is recommended that you use this table during the initial
analysis of a system's memory requirements. Once implemented, Adabas System
Coordinator Online Services may be used to more accurately monitor the amount
of real memory in use.
| Memory requirement (per session) for each... | Size (in bytes) | |
|---|---|---|
| session area (one only) | 512 | |
| database accessed | + 160 | |
| file accessed | Adabas file | + 80 |
| Adabas Vista translation file | + 80 + 64 + 48 | |
| Adabas Vista partitioned file | + 80 + 64 + (48 + partitioning field length + partition concurrency * 5) * number of partitions | |
| Command ID issued against | an Adabas file | + 80 |
| an Adabas Vista translation file | + 36 + 80 | |
| an Adabas Vista partitioned file | + (256 + 80 * number of involved partitions) + (length of Adabas buffers * number of involved partitions) | |
| record held (within a transaction) against | an Adabas file | + 64 |
| an Adabas Vista translation file | + 64 | |
| an Adabas Vista partitioned file | + 64 * number of involved partitions |
Estimate the per session memory requirements for an application which has the following characteristics:
two databases
five Adabas files
two Adabas Vista translation files
one Adabas Vista partitioned file
Partitioning field length is eight bytes
User partition concurrency is eight
Number of partitions is three
Majority of access is distributed (all three partitions involved)
Average length of Adabas buffers is 1000 bytes
Maximum Command ID concurrency of two (one Adabas file and one Adabas Vista partitioned file)
Average number of successful hold commands between
ET/BT is 20
18 against Adabas files
two against Adabas Vista partitioned file
| User session area: | 512 | |
| Database requirements: | (2 * 160) | 320 |
| File requirements: | (5 * 80) + (2 * 192) + 1 * 432 | 1216 |
| Command ID requirements: | 80 + 3496 | 3576 |
| Held record requirements: | 18 * 64 + 2 * (64 * 3) | 1536 |
| Total | 7160 |
Multiply this value by the estimated number of application clients to estimate the application memory requirements.
If a single TP system is host to multiple applications, repeat this process for each application to provide an overall estimate of the TP memory requirements.
The required memory is requested from either
local TP memory using the host TP services; or
shared memory using the Adabas System Coordinator daemon.
The use of shared memory depends on whether the job is defined as a clustered application using job types such as CICS Cluster, IMS, or UTM.
Note:
It is strongly recommended that you discuss the use of such job types
with your system programmer before you implement them.
