MEMORY USAGE · Valkey

MEMORY USAGE

Estimates the memory usage of a key.

Usage

MEMORY USAGE key [SAMPLES count]

Description

The MEMORY USAGE command reports the number of bytes that a key and its value require to be stored in RAM.

The reported usage is the total of memory allocations for data and administrative overheads that a key and its value require.

For nested data types, the optional SAMPLES option can be provided, where count is the number of sampled nested values. The samples are averaged to estimate the total size. By default, this option is set to 5. To sample the all of the nested values, use SAMPLES 0.

Reply RESP2

One of the following:

Reply RESP3

One of the following:

Complexity

O(N) where N is the number of samples.

ACL Categories

@read @slow

Examples

With Valkey v7.2.4 64-bit and jemalloc, the empty string measures as follows:

> SET "" ""
OK
> MEMORY USAGE ""
(integer) 56

These bytes are pure overhead at the moment as no actual data is stored, and are used for maintaining the internal data structures of the server (include internal allocator fragmentation). Longer keys and values show asymptotically linear usage.

> SET foo bar
OK
> MEMORY USAGE foo
(integer) 56
> SET foo2 mybar
OK
> MEMORY USAGE foo2
(integer) 64
> SET foo3 0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789
OK
> MEMORY USAGE foo3
(integer) 160

History

See also

ACL, ACL CAT, ACL DELUSER, ACL DRYRUN, ACL GENPASS, ACL GETUSER, ACL HELP, ACL LIST, ACL LOAD, ACL LOG, ACL SAVE, ACL SETUSER, ACL USERS, ACL WHOAMI, BGREWRITEAOF, BGSAVE, COMMAND, COMMAND COUNT, COMMAND DOCS, COMMAND GETKEYS, COMMAND GETKEYSANDFLAGS, COMMAND HELP, COMMAND INFO, COMMAND LIST, CONFIG, CONFIG GET, CONFIG HELP, CONFIG RESETSTAT, CONFIG REWRITE, CONFIG SET, DBSIZE, DEBUG, FAILOVER, FLUSHALL, FLUSHDB, INFO, LASTSAVE, LATENCY, LATENCY DOCTOR, LATENCY GRAPH, LATENCY HELP, LATENCY HISTOGRAM, LATENCY HISTORY, LATENCY LATEST, LATENCY RESET, LOLWUT, MEMORY, MEMORY DOCTOR, MEMORY HELP, MEMORY MALLOC-STATS, MEMORY PURGE, MEMORY STATS, MODULE, MODULE HELP, MODULE LIST, MODULE LOAD, MODULE LOADEX, MODULE UNLOAD, MONITOR, PSYNC, REPLCONF, REPLICAOF, RESTORE-ASKING, ROLE, SAVE, SHUTDOWN, SLOWLOG, SLOWLOG GET, SLOWLOG HELP, SLOWLOG LEN, SLOWLOG RESET, SWAPDB, SYNC, TIME.