DEL and UNLINK for deletion in Redis

Introduction

DEL and UNLINK are commands to remove keys from Redis. They help clean up data you no longer need.

When you want to delete a key and its value immediately.

When you want to delete keys without blocking Redis for a long time.

When cleaning up expired or temporary data.

When you want to free memory by removing unused keys.

When you want to delete multiple keys at once.

Syntax

Redis

DEL key [key ...]
UNLINK key [key ...]

DEL removes keys synchronously, blocking Redis until done.

UNLINK removes keys asynchronously, freeing Redis quickly.

Examples

Deletes the key named 'mykey' immediately.

Redis

DEL mykey

Deletes multiple keys at once.

Redis

DEL key1 key2 key3

Removes 'mykey' asynchronously without blocking Redis.

Redis

UNLINK mykey

Asynchronously deletes multiple keys.

Redis

UNLINK key1 key2

Sample Program

Sets a key 'mykey', deletes it with DEL, then checks if it exists.

Redis

SET mykey "hello"
DEL mykey
EXISTS mykey

Important Notes

DEL returns the number of keys it deleted.

UNLINK also returns the number of keys it scheduled for deletion.

Use UNLINK for large keys to avoid blocking Redis.

Summary

DEL deletes keys immediately and blocks Redis during deletion.

UNLINK deletes keys in the background without blocking.

Both commands accept multiple keys to delete at once.