I am a data engineer who uses both Apache Kafka for streaming as well as Delta for storage on lakes. This is more of a question to feed my curiosity. I can see both the Delta transaction log files (which are of .json extension ) as well as the Kafka topic log files (which are of .log extension) are named in the same way with zeros left padded up to 20 digit length.
E.g.:
00000000000000000000.log,00000000000000000001.log --> Kafka topic log files
00000000000000000000.json,00000000000000000001.json --> Delta transaction log files
Why the standard is 20 digit length? Why can't it be 19 or 21?