Please contact us if you face any kind of HANA performance issues.
If your are running HANA SPS5 or SPS06 (>Rev65) with an ABAP stack with one of the affected kernels you have to follow the instructions provided by SAP or contact XLC.
It is important if you use the new kernel wit the fix, you have to regenerate the ABAP loads via SGEN of the impacted code.
If you use the SPS06 workaround, you have to clear the SQL plan cache after implementing the parameter:
ALTER SYSTEM ALTER CONFIGURATION ('indexserver.ini', 'SYSTEM' ) SET ('sql', 'prefer_cs_itab_in_subquery_for_param_itab') = 'true' WITH RECONFIGURE COMMENT 'SAP Note 3149562. <ADDITIONAL ACTION: Revert after upgrade to a revision containing the fix>';
ALTER SYSTEM CLEAR SQL PLAN CACHE;A