What is the difference between certain JedisCommands which seem to be functionally equivalent to java.lang.String class

Question

What is the difference between substr command from JedisCommands and java.lang.String

substr

Answer 1

Redis' substr command is performed in Redis server, so you don't need the whole string in you Java client to perform the operation. E.g.: If it's a long string (e.g.: 1G) you don't need to fetch it all to get the first few bytes, reducing memory usage and the network connection between your Java client and Redis.

Another difference is that Java's substr is about characters, while Redis' substr is about bytes. That makes a huge difference when dealing with UTF-8 strings.