Data folding is the process of removing duplicated measures from successive messages.
Similarly, journaling can be used to select distinct measures and count their occurrences in discrete time intervals.
For example, the coordinate positions in a message stream can be folded into distinct values and their occurrences counted for each one-minute interval. The journal would be defined for a query like:
GROUP BY x,y,z;
Data folding is useful where measures are mostly static and the repeated values create excessive noise in the data.