GETSET(3valkey)

✨ GETSET ✨

okay so bestie, this is valkey's GETSET — it's giving "swap the vibes and tell me what was there before". Manual page? we're in the 3valkey manual, obvs 💅

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💖 NAME 💖

getset — returns the previous string value of a key after setting it to a new value. like, it hands you the old thing and then replaces it. iconic behavior fr fr 🎀

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🦋 SYNOPSIS 🦋

GETSET key value

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🌸 DESCRIPTION 🌸

So basically: GETSET atomically sets key to value and returns the old value that was chillin' at key. Atomic. No cap. It all happens in one go, no sneaky middle state. ✨

🚨 But listen — it returns an error when key exists but does not hold a string value. So if you're pointing this at a list or a hash or whatever, bestie, it's gonna yell at you. 💀

Also: any previous time to live associated with the key is discarded on a successful SET operation. Your TTL? gone. evaporated. not invited to the function. 😭

🌈 Design pattern 🌈

GETSET can be used together with INCR for counting with atomic reset. Obsessed with this one actually.

So like, a process may call INCR against the key mycounter every time some event occurs, but from time to time we need to get the value of the counter and reset it to zero atomically. That's the whole vibe. This can be done using GETSET mycounter "0":

127.0.0.1:6379> INCR mycounter
(integer) 1
127.0.0.1:6379> GETSET mycounter "0"
"1"
127.0.0.1:6379> GET mycounter
"0"

read it and reset it, no race condition, main character energy only 👑

💜 Alternative 💜

SET with the GET argument. (iykyk — the new hotness, but GETSET still ate, don't worry.)

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🎀 REPLY 🎀

💅 RESP2

One of the following:

• valkey-protocol(7) Bulk string reply: the old value stored at the key.
• valkey-protocol(7) Nil reply: if the key does not exist.

🫶 RESP3

One of the following:

• valkey-protocol(7) Bulk string reply: the old value stored at the key.
• valkey-protocol(7) Null reply: if the key does not exist.

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⭐ COMPLEXITY ⭐

O(1)

constant time, babe. fastest girl in the room. 🔥

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👑 ACL CATEGORIES 👑

@fast @string @write

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🦄 HISTORY 🦄

• Available since: 1.0.0

like... ancient. a legend. the blueprint. 🌈

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🍓 EXAMPLES 🍓

127.0.0.1:6379> SET mykey "Hello"
OK
127.0.0.1:6379> GETSET mykey "World"
"Hello"
127.0.0.1:6379> GET mykey
"World"

see how it gave you back "Hello" and left "World" behind? that's the whole trick. ate and left no crumbs 💖

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💜 SEE ALSO 💜

append(3valkey), decr(3valkey), decrby(3valkey), delifeq(3valkey), get(3valkey), getdel(3valkey), getex(3valkey), getrange(3valkey), incr(3valkey), incrby(3valkey), incrbyfloat(3valkey), lcs(3valkey), mget(3valkey), mset(3valkey), msetnx(3valkey), psetex(3valkey), set(3valkey), setex(3valkey), setnx(3valkey), setrange(3valkey), strlen(3valkey), substr(3valkey)

go read the whole friend group, they're all slaying in their own way 🧚

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and that's the page, bestie!! this was version 9.0.0, dated 2025-10-21, from the GETSET(3valkey) manual — mwah, ily, go reset some counters atomically 💖✨🎀