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How do you use the EXISTS and RENAME commands, and what should you be careful about when using RENAME?

Intermediate

Answer

EXISTS checks whether one or more specified keys are currently present in Redis, returning a count of how many of them actually exist, while RENAME changes an existing key's name, but you should be careful since RENAME will silently overwrite any existing key that already has the new target name, potentially causing accidental data loss.
EXISTS mykey
RENAME oldname newname
Real-world example A developer accidentally overwrites important cached data using RENAME, learning to first check with EXISTS or use RENAMENX, which only renames if the target name does not already exist, to avoid this kind of mistake in the future.

Common follow-ups: What does RENAMENX do differently from the regular RENAME command?;What happens if you try to rename a key that does not exist?

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All 7 Redis CLI & Basic Commands questions