SAP HANA - Table size in Main Memory after archiving
I'm working on the optimisation of table size on a "small" SAP ECC running on HANA system. It's a small but old system and I decided to test the impact of archiving (SARA). I get followinf results and have some trouble to understand:
1) Starting point: Table BSEG. Size in Total Memory on Hana: 6 Gb for 100 M of entries
2) I run archiving with ECC transaction SAR and archive/delete 27 M of entries
3) I forced MERGE
4) Table BSEG: Size in Total Memory on Hana increased to 9 Gb for 73 M of entries !!!!
5) I forced "Optimize_compression"
6) 4) Table BSEG: Size in Total Memory on Hana decreased to 3,7 Gb for 73 M of entries !!!!
I thought that doing a MERGE was doing an optimization of compression in the same time.
What happened ? I noticed that when archiving objects some tables gets bigger (KONV, BSEG) in memory and some get smaller (CDPOS).
Thanks for your help.