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NCACHE.CREATE

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NCACHE.CREATE namespace [MAX_ENTRIES n] [TTL seconds]
Group
Keyed caches
Complexity
O(1)
Arity
-2 (at least 2 words, counting the command name)
Flags
write, fast
Keys
first 1, last 1, step 1
HotKV Cloud
Performance and Scale
On-Premise
requires the negative-cache license feature

The negative cache holds negative results, such as “user not found” or “refused by moderation”, usually with a short TTL, so repeated lookups for the same missing or refused item do not reach your backend or model again. NCACHE.CREATE creates a namespace. You must create a namespace before you can store entries in it with NCACHE.SET.

Options

Section titled “Options”
Option Effect
MAX_ENTRIES n Maximum number of entries. 0 or omitted uses the server’s per-namespace limit, and larger values are capped at that limit (max_entries_per_namespace under [ncache]). When the namespace is full, HotKV evicts existing entries to make room.
TTL seconds Default time to live for entries stored without their own TTL. 0 or omitted means entries do not expire.

Options can be given in any order and are case-insensitive.

Return value

Section titled “Return value”
Case RESP2 RESP3
Namespace created Simple string OK Same

Errors:

  • ERR namespace already exists or limit reached if the namespace exists, or the server already holds its maximum number of negative cache namespaces (max_namespaces under [ncache]).
  • ERR invalid MAX_ENTRIES or ERR invalid TTL if a value is not a non-negative integer.
  • ERR unknown option for any other option name.
  • ERR wrong number of arguments for 'ncache.create' command if the argument count is wrong.
  • NOLICENSE negative-cache requires a HotKV license. Contact sales@hotkv.com if your license does not include the negative-cache feature.

Examples

Section titled “Examples”
127.0.0.1:6379> NCACHE.CREATE lookups MAX_ENTRIES 50000 TTL 60
OK
127.0.0.1:6379> NCACHE.CREATE lookups
(error) ERR namespace already exists or limit reached

Compatibility

Section titled “Compatibility”

HotKV-only command. Redis and Valkey have no equivalent.

See also

Section titled “See also”

NCACHE.SET, NCACHE.GET, NCACHE.DEL, NCACHE.STATS, NCACHE.FLUSH, NCACHE.DROP, NCACHE.LIST, AI features guide