ABAP custom code adaptation for SAP HANA DB migration

[anversha_s]

Introduction

Objective of this blog is to provide a quick and short reference for custom code adaptation for SAP HANA database migration.

Scenario -  ERP system running on any DB to Business Suite on SAP HANA

Key Points to remember

• 
  
  SAP HANA runs only on Unicode.
  
  


• SAP HANA database is available only for SAP systems based on SAP Netweaver Application Server ABAP or for SAP systems based on SAP Netweaver Application Server Java. It is not available for SAP NetWeaver dual-stack (ABAP+Java) systems such as SAP Process Integration.

Refer here for the system prerequisite.

Once the prerequisite are completed, system is ready for the custom code adaption .There are 3 key aspects for custom ABAP code adaptation for SAP HANA.

Mandatory Corrections

• Avoid functional regression


• Code build on specific DB
  
  
  
  • Eg. Native SQL
  
  
  
  

SQL performance optimizations

• Focus on frequently running SQL

Code pushdown

• CDS


• SQL Script

Recommended tools

For functional corrections

• Static code check tools - Code Inspector and the ABAP Test Cockpit.


• Variants Integrated in Code inspector (SCI).
  
  
  
  • FUNCTIONAL_DB
  
  
  • FUNCTIONAL_DB_ADDITION
  
  
  • Implement Note 1935918 ( In case variant not found )
  
  
  
  


• Build unit tests and scenario tests for functional correctness


• Variant FUNCTIONAL_DB check for:
  
  
  
  • Finding Native SQL
  
  
  • Database (DB) hints
  
  
  • Finding ADBC (ABAP Database Connectivity) Usages
  
  
  • Finding usages of special DDIC function modules that check or return the existence or technical properties of certain DB indexes.
  
  
  • Finding accesses to technical pools/clusters of a pool/cluster table
  
  
  • Finding non-robust ABAP code that relies on non-ensured/implicit sorting of certain SQL queries, although no ORDER BY clause is used. There are two different checks available for finding non-robust ABAP code:
  
  
  • “Search problematic statement…w/o ORDER BY”
  
  
  • “Depooling/Declustering: Search for…w/o ORDER BY ”
  
  
  
  

For performance optimizations

• SQL Monitor (NetWeaver 7.40). (Tcode SQLM)
  
  
  
  • Run in old productive system for ~ 2 weeks (at least)
  
  
  • No system overhead.
  
  
  
  


• Sort the SQL Monitor results in transaction SQLM by “number of execution”


• Optimize the 10-20 Top most executed SQLs in your custom code using OPEN SQL,CDS, AMDP approach based on the scenarios.


• Additional performance hint
  
  
  
  • Variants Integrated in Code inspector (SCI).
    
    
    
    • PERFORMANCE_DB
    
    
    
    
  
  
  
  


• Don’t fix the static findings without looking in the SQL monitor before.


• Activate Usage Procedure Logging (UPL) in production system.(New name is SCMON).
  
  
  
  • Before the migration starts
    
    
    
    • Purpose : Limit work package
    
    
    • T Code - /SDF/UPL_CONTROL
    
    
    • Default number of days for which UPL data will be collected is 14( Max 99) days.
    
    
    • Result is analyzed to identify productively used code
    
    
    • Cleaning up of non-productively used code before the migration
    
    
    
    
  
  
  
  

Software Update Manager (SUM)

• Perform a release upgrade, install enhancement packages, apply Support Package Stacks, install add-ons, or updating single components on SAP NetWeaver


• Ensure that the entire data from the original database is copied to the HANA db


• Performs a row-count at the end of the DB migration.


• Compare the row-count from the tables in source DB with the row-count of the tables in the HANA DB.


• Create CRC (Cyclic redundancy checksums) , check that the content of the tables is still the same.

Conclusion

This blog is touching only on on exact steps which is key for custom code adaption . Please explore for in depth understanding of each sections.

Another blog will be published soon for quick reference on custom code adaptation for S/4HANA migration. Stay tuned. Happy learning.

[Jelena_Perfiljeva]

I'm curious, are any SAP customers actually migrating from ECC to Business Suite on HANA these days? That would seem like a moot point to me... It would've made sense few years ago when S/4 HANA was not quite there yet. But at this point it'd make more sense to either ride ECC until the wheels fall off or just go to S/4.

Also you're saying there will be another blog regarding S/4 HANA but this SAP blog from 2016 covers both scenarios as they seem to be quite similar (as far as ABAP and tooling goes). So why did you choose to split it up?

And how is the whole SUM part relevant to ABAP code adaptation? It looks like some Basis activity. Quite confused on this one.

It would've been better if you shared some personal experience from a project, for example, and added more explanatory text in general. Otherwise this seems like a checklist rather than a blog, sorry. Much room for improvement.

[anversha_s]

Hi Jelena,

Most of the customers are migrating from ECC to Suite on HANA and later to S/4 HANA and it will one of the key activities in coming years along with green field S/4 Hana implementations. Consultants are getting opportunities in migration projects and many of them are into it .

This blog is touching only on on exact steps which is key for custom code adaption .

Also SUM activity is mentioned for the awareness purpose even though it’s a basis activity. This will help a technical consultant to understand about the database copying activity.

Thanks for your feedback

Thanks

Anversha

[Jelena_Perfiljeva]

"Most of the customers"? What is the source for this information?

I don't have the specific numbers but based on what I've heard at the conferences, ASUG meeting, online, and through personal connections, this is not at all the case. I've heard of many projects to migrate to S/4 but maybe one to migrate to Business Suite.

[vinay_udekar]

Hey Anversha,

I found an exact replica of your post. Your post is dated 11-Dec-2019 and the other post is 12-Dec-2019. People can really copy-paste 🙂

http://www.hanaexam.com/2019/12/abap-custom-code-adaptation-for-sap-hana-db-migration.html

[anversha_s]

Hello Vinay,

 

Thanks for highlighting the same. Seems they copied my content on the next day I published. Cant do anything. Anyway knowledge is shared 🙂  Thanks for figuring it out