How to remove old data in redis when updating data? - redis

Question

I'm setting data in redis, but I update that data every minute, and I need redis to replace the old data with the new updated one. I am very confused as to how I might be able to achieve that. I tried to use client.expire('key', 60), but that doesn't seem to work. Below is my code. Any help would be appreciated. Thanks in advance.
var redis = require("redis"),
client = redis.createClient();
const { promisify } = require("util");
const setAsync = promisify(client.set).bind(client);
async function run(){
//do something
const success = await setAsync('mykey', list);
console.log({success});
client.expire('mykey', 59);
}

Answer 1

It seems like the key will be deleted (or more precisely, marked for deletion) 59 seconds after calling client.expire, but there are 2 things you need to be aware of:
If you call the EXPIRE command on a key that already have a TTL, it'll override the pervious TTL.
The expiration timeout is cleared once the value of the key is overwritten (using SET, DEL, etc.).
BTW, in case you're updating the exact same key, the data will be overwritten anyway.. for example:
await setAsync('key', 'value1'); // set 'key' to 'value1'
await setAsync('key', 'value2'); // override 'key' to 'value2'
await getAsync('key'); // 'value2'
Also, instead of running two commands, one for setting the value and one for setting the TTL, you can use the EX option like that:
setAsync('key', 'value', 'EX', 60); // set `key` to `value` with TTL of 60 seconds