11-07-2007 11:23 AM
Hi,
we think about using ABAP shared objects in parallel processing to avoid reading the same data from the DB for every parallel process.
Currently we have 15MB shared memory configured according to SHMM.
My Questions:
1. How do we extend the shared memory? What is the limit?
2. Does anyone have experience with large shared objects? (1-2GB)
Thanks in advance
regards
Steffen
08-16-2009 3:15 PM
Steffen,
Please review OSS note 1322182 that talks about extending Shared Memory that should possibly address your queries.
Naresh
08-17-2009 8:40 AM
Hi Steffen,
the parameter is abap/shared_objects_size_MB, the limit is defined by your available memory.
I have seen sizes with 8 GB in production so far.
Regarding the big shared objects: Carefully think about who is reading and writing and when
these actions happen. With versioning you can easily have a much higher memory consumption
since update requests will create a new version while readers attached to the old version
keep the old version alive. Besides that i haven't seen much trouble with shared objects so far,
but maybe other people have other experiences.
Please share your experients with us if you use the shared objects.
Kind regards,
Hermann
08-17-2009 10:19 AM
I think you should try, shared objects are used in newer systems more and more so 1-2GB is not very special.
As the shared objects are explicitly used performance problems are rare, similar to shared buffers and shared memory.
The table buffers cause more problems because of their much higher usage and the implicit use, Open SQL switches to buffer it the technical setting of the buffer is changed ... but in some cases the switch does not work.
Siegfried