Some user defined functions have non-trivial initialization phases that in the ideal case, would not be repeated for each record of a mapper's input. Some work-arounds include the use of static variables (need to worry about multiple threads) and the registry infrastructure in jaql (as used for random number sampling). The first option may not be safe and the second requires jaql code to be modified which is not a good long option.

While there is merit in exposing the registration infrastructure, a better option is to support initialization for user-defined functions.

Issue 7 has been merged into this issue.