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SORT_RO

Syntax​

SORT_RO key [LIMIT offset count] [ASC | DESC] [ALPHA]

Time complexity: O(N+M*log(M)) where N is the number of elements in the list or set to sort, and M the number of returned elements. When the elements are not sorted, complexity is O(N).

ACL categories: @read, @set, @sortedset, @list, @slow

Read-only variant of the SORT command. It is exactly like the original SORT command but refuses the STORE option and can safely be used in read-only replicas.

Since the original SORT has a STORE option it is technically flagged as a writing command in the Redis command table. For this reason read-only replicas in a Redis Cluster will redirect it to the master instance even if the connection is in read-only mode.

The SORT_RO variant was introduced in order to allow SORT behavior in read-only replicas without breaking compatibility on command flags.

See SORT for more details about the command and its options.

Dragonfly Support​

Dragonfly currently supports the following options for SORT_RO:

  • ASC / DESC - Sort order
  • ALPHA - Lexicographical sorting
  • LIMIT offset count - Limit results

The following options are not yet supported:

  • BY pattern - Sort by external keys
  • GET pattern - Retrieve external keys

Return​

Array reply: list of sorted elements.

Examples​

dragonfly> LPUSH mylist 3 1 2
(integer) 3

dragonfly> SORT_RO mylist
1) "1"
2) "2"
3) "3"

dragonfly> SORT_RO mylist DESC
1) "3"
2) "2"
3) "1"

dragonfly> SORT_RO mylist ALPHA
1) "1"
2) "2"
3) "3"

dragonfly> SORT_RO mylist LIMIT 0 2
1) "1"
2) "2"