It's neither a tip, nor a trick. It's more a statement:
ALL data is kept in memory
"No shit" some of you might say, but I actually have to confess: I did not know that when I started using redis. I always assumed "there is a file on the disk, that is where my data lives".
The truth is: all of redis' data is kept in memory and from time to time it is also written to disk
This has 2 effects:
- As the database grows, so grows its memory consumption
- If your machine crashes all data that hasn't been written to the disk is lost.
So keep that in mind when you want to use redis.