I personally love the current statement in the SAP HANA troubleshooting guide regarding HEX:

"In SAP HANA, the SQL query processor parses SQL statements and generates SQL query execution plans.

As the query processor and the query optimizer continue to be developed (in, for example, the new HANA

Execution Engine - HEX) the resultant execution plans for a given query may change from one HANA release to

another, or the plan may change because the data being queried has been reorganized; it is therefore possible

that the performance of an SQL query statement may degrade."

With SPS06 and even more so with SPS07, the HEX engine was used more frequently. This results on the one hand side in easy scenario to perfect results with lower memory and CPU consumption ending up in faster response times. But in scenarios with FAE (for all entries) together with FDA (fast data access), it can result in bad performance. We faced scenarios with 10x times more runtime and +30% CPU load. There are also other scenarios, please have a look at the table below. After some customers upgraded their first systems to SPS07 I recommended to wait for Rev. 73/74, but some started early with Rev. 71/72 and we had to troubleshoot many statements. If you have similar performance issues after the upgrade to SPS07 feel free to contact us!

Our current recommendation is to use min. Rev. 79 with some workarounds. The performance degradation is extreme in systems like EWM and BW with high analytical workload, but also a lot of S/4 systems are affected. Some issues can only be fixed with an update. This means no workaround!

There are also cases in SAP standard coding that can be solved using always the latest SAP's delivered statement hints (2700051) or by implementing SAP notes for adding an ABAP hint (e.g. 3359519). We are checking this performance aspects in our health check services. If you want to be on the safe side, contact us - it's better to be safe than sorry.

### Update 11 / 2024 ###

Starting with Rev. 76, the problems became less. But in the last weeks more and more customers with special scenarios upgraded to SPS07 and again a lot of new issues raised. The new recommendation is to use at least Rev. 79 with workarounds.

Here we collected some of the current notes which affecting the performance of the system in the context of HEX [status: 05-11-2024]: