The extract rule was mainly designed to run using the BIX command line and that is our recommended way to extracting data. When running from the command line, there is no access to parameters and thus the extract rule has not been designed to accept the same.
In command line options, you can leverage the -u and -U options to limit the ranges of records that you need to extract in one run. Please refer to the BIX user guide for details on how to run in command line - https://pdn.pega.com/documents/bix-71-user-guide
You are right it is applicable for extracting to external DB.
So the only option is to split the file is -u and -U parameters.
I don't have much idea about writing shell scripts. But my logic should be to make this java call in a loop and pass the arguments(pxUpdateDateTime) that should be evaluated dynamically before the call,
If anyone has attempted this before, please share the code