Hendrik Muhs 5a0c32833e Add a checkpoint service for data frame transforms (#39836)
Add a checkpoint service for data frame transforms, which allows to ask for a checkpoint of the
source. In future these checkpoints will be stored in the internal index to

 - detect upstream changes
 - updating the data frame without a full re-run
 - allow data frame clients to checkpoint themselves
2019-03-22 10:25:30 +01:00
..