I have been investigating the ‘time travel’ concept as it potentially looked very useful for reporting on historical master data.
However having read the thread http://scn.sap.com/message/14197641 by Justin Molenaur and the responses by Lars I was very disappointed.
Essentially Time Travel can do exactly what you want it to do if you manually update the data (remember to turn off auto commit) and use SQL to interrogate it.
(see the SAP technical paper – “ SAP HANA - Time Travel Example” by Jack Boers)
All fine but of little use. What we need to be able to do is use time travel in the HANA models to enable queries to run and display master data as of a point in time.
SAP need to urgently enhance this feature to integrate it with SLT and allow Analytic/Calculation views to make use of it.
Lars mentioned “it looks as if you try to replace the complex data staging/loading handling present in SAP BW by something much simpler and by sneaking in a kind of time-dependency through usage of the history table feature” – and of course that is EXACTLY what we do want to do, not in a sneaky way but in a way supported by SAP – it should be very simple to do.
SLT does capture all changes in the source system so why not use these changes to populate a history table so that you can query it with your HANA models??? The response to use BODS etc is just not acceptable. We use SLT precisely because it is real time and does capture these changes. It should not need to do any transformation, it just replicates the ECC changes to HANA where it should be possible to store them in a history table.
SAP need to
1) 1) Enable SLT to populate history tables (currently SLT can replicate to a history table but the commit id’s are not maintained)
2) 2) Enable Analytic and calculation views to query the history tables
Why should we be forced to have to use BODS and somehow update the valid to date of the latest existing version of a record when we get a new one coming through? So much effort for every SAP customer to try and re-invent the BW time dependent master data concept in HANA when SAP could with a few simple extensions actually make time travel useful. So over to SAP - how about it?
Andy