FLUSHDB

Introduction and Use Case(s)

FLUSHDB is a Redis command used to remove all keys from the current database. This command is typically used in scenarios where you need to clear out an entire Redis database, such as during testing, development, or when resetting environments.

Syntax

  1. FLUSHDB [ASYNC]

Parameter Explanations

  • ASYNC: (Optional) If specified, the database will be cleared asynchronously, allowing the server to continue processing other commands while the deletion is in progress.

Return Values

The return value of the FLUSHDB command is a simple string reply indicating the success of the operation.

Example outputs:

  • Without ASYNC:

    1. OK

  • With ASYNC:

    1. OK

Code Examples

  1. dragonfly> SET key1 "value1"
  2. OK
  3. dragonfly> SET key2 "value2"
  4. OK
  5. dragonfly> KEYS *
  6. 1) "key1"
  7. 2) "key2"
  8. dragonfly> FLUSHDB
  9. OK
  10. dragonfly> KEYS *
  11. (empty list or set)

Using ASYNC:

  1. dragonfly> SET key1 "value1"
  2. OK
  3. dragonfly> SET key2 "value2"
  4. OK
  5. dragonfly> FLUSHDB ASYNC
  6. OK
  7. dragonfly> KEYS *
  8. (empty list or set)

Best Practices

  • Use FLUSHDB cautiously in production environments, as it will irreversibly delete all keys in the current database.
  • Consider using FLUSHDB ASYNC for larger datasets to avoid blocking the Redis server.

Common Mistakes

  • Using FLUSHDB without realizing it clears only the current database, not all databases. To clear all databases, use FLUSHALL.
  • Forgetting that ASYNC does not guarantee immediate deletion but allows the server to handle other operations concurrently.

FAQs

Is there a way to recover data after using FLUSHDB?

No, once FLUSHDB is executed, the action is irreversible, and all data in the current database is permanently deleted. Always ensure you have backups if needed.

Does FLUSHDB affect other databases in Redis?

No, FLUSHDB only removes keys from the currently selected database. Other databases in the same Redis instance remain unaffected.