topic Re: large shared objects in Application Development and Automation Discussions

large shared objects

former_member772174 — Wed, 07 Nov 2007 11:23:50 GMT

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

Re: large shared objects

Former Member — Sun, 16 Aug 2009 14:15:08 GMT

Steffen,

Please review OSS note 1322182 that talks about extending Shared Memory that should possibly address your queries.

Naresh

Re: large shared objects

HermannGahm — Mon, 17 Aug 2009 07:40:47 GMT

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

Re: large shared objects

Former Member — Mon, 17 Aug 2009 09:19:20 GMT

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