Efficient way redis set member update

问题:

I have a redis set. This set can store 20 members maximum(added withSADD command). My problem is ; I need to update that members when needed. Members need that modification maximum 10 times for every member. Set members are json as a string. There is only solutoin on my mind nor, get all members update and recreate that set again. But it seems iditoic.

I know there is ZADD sorted set with its score support it seems suitable also I need to update score like data in json , but i just wonder Is there any method updating members in efficient way, or is updating member not acceptable on redis way ?

Note: Redis datastore is using by both node.js and java clients.

回答1:

Set members themselves are immutable - you can add new members or remove existing ones. That's it.

Given that a set is an unordered collection of unique members, consider the possible outcomes were set members theoretically modifiable when the new value for a member:

1. is identical to the old value - no change to the set
2. already exists in the set - equivalent to deleting that member
3. isn't 1 or 2 - equivalent to deleting the member and adding a new one