PHP Redis keys
method is commonly used to retrieve all keys matching a certain pattern in a Redis database. This can be useful in several scenarios such as debugging, maintenance tasks, or when you need to manipulate set of data identified by similar key patterns.
Example 1: Get all keys
In this example, we will get all the keys in our Redis instance. The asterisk (*) is a wildcard that matches all keys.
$redis = new Redis(); $redis->connect('localhost', 6379); $allKeys = $redis->keys('*'); print_r($allKeys);
Example 2: Get keys with a specific pattern
In this case, we're looking for keys that start with 'user':
$redis = new Redis(); $redis->connect('localhost', 6379); $userKeys = $redis->keys('user*'); print_r($userKeys);
The 'user*' pattern will match any keys that start with 'user'.
Be careful when using the keys
command in a production environment, especially with large databases and broad patterns, as it may degrade performance.
If possible, use the SCAN
command instead of KEYS
. SCAN provides a cursor-based iterator which is more efficient and doesn't block the server.
Using KEYS in production environments: The KEYS
command can negatively impact performance on large databases, so it's not recommended for production environments. Instead, consider using SCAN
or maintain an index of your keys in a separate data structure.
Ignoring return types: The KEYS
command returns an array of strings representing the matching keys or FALSE
if there are no keys. Always ensure to handle these return types correctly in your application.
Q: Can I use patterns with the Redis keys
method?
A: Yes, you can use patterns when retrieving keys. For example, 'user*' will match any keys that start with 'user'.
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement.