In Node.js applications using Redis as a database, one common use case is fetching the initial subset of keys for pagination or to limit the number of results returned from a large dataset.
Here's how you can do it using node-redis.
This example lists all keys in the Redis store and slices the first 10. It's simple, but not very efficient for large datasets because it fetches all keys before slicing.
KEYSfor production code where there are many keys.
KEYScan block the server when it is used against large databases.
SCANprovides a cursor-based iteration which is more efficient and doesn't block the server.
KEYSin a production environment: The
KEYScommand can be resource-intensive and slow down your Redis server, especially when dealing with large amounts of data. It's recommended to use
SCANfor such scenarios.
Q: What's the difference between
KEYS returns all the keys matching a pattern at once, which can block the Redis server if it's dealing with large datasets.
SCAN, on the other hand, uses a cursor to incrementally iterate over the keys, minimizing the impact on performance.