That’s interesting and makes sense. SAP introduced HANA NLS (nearline storage) based on Sybase IQ to address your use case (I think). HANA HTAP is in-memory while IQ works with shared storage clusters so it’s ideal for offloading massive amounts of historical BW data that doesn’t fit in memory.
In-Memory HANA is freakishly good for running OLAP BW queries against fresh data. Column stores like HANA and IQ are both good at this, but to be honest, I don’t know how BW systems were typically configured before HANA/IQ.
I have to admit I'm not super involved with the system in question, and it's possible the team is underfunded or just not that great.
But we definitely ended up in a situation where it was hard to get to some important data, since the team couldn't SLT it to BW because "it's too many transactions" and trying to get it from Sidecar was blowing up, because it's too much data. And that was already with S/4.
But again, I don't know why it was the case. It would have been great and saved us a lot of work if it worked out and we could've done stuff in HANA directly, instead of copying data to different OLAP system daily. Especially now, when everyone is trying to get on the realtime-train.
In-Memory HANA is freakishly good for running OLAP BW queries against fresh data. Column stores like HANA and IQ are both good at this, but to be honest, I don’t know how BW systems were typically configured before HANA/IQ.