Hi! Even I set FULL history details level, only VariableUpdates entities are stored. Is it by design or saving other history details (first of all interesting Assignment entity) just not implemented yet?
Full should give you process instance history, activity instance history, task assignment history, variable update and form property updates (if used).
I have only VariableUpdate records in my ACT_HI_DETAIL table. Probably I have something misconfigured (I'm using spring for configuring Process Engine) If this is not reproduced in your case - so, it is specific for my configuration - it is not a big problem - since I've already created "parallel" history table (I need additionally store user performed the action and comment, so, I'm storing required history records by myself).