DELEX

Conditionally removes the specified key based on value or hash digest comparison.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	DELEX
Catalog group	String commands
Upstream since	8.4.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

DELEX key [IFEQ ifeq-value | IFNE ifne-value | IFDEQ ifdeq-digest |
  IFDNE ifdne-digest]

ffkv behavior and limits

Keys and values are binary-safe bytes. Conditional SET and DELEX comparisons use the stored bytes; DIGEST uses XXH3, not a cryptographic digest.

Source: README.md:571–585; src/engine/strings.rs; tests/bdd/features/strings.feature.

Data-changing administration: use an isolated dataset or a verified backup. Lost replies have an unknown outcome; never blindly replay a destructive operation.

All requests share the 8 MiB framing/1,024-argument ingress limit; normal RESP replies have 64 MiB wire/logical budgets with bounded nesting/value counts. Management and Lua origins impose smaller budgets. These are not a process RSS cap. Catalog inclusion is not exhaustive option or wire-format parity. See limits and compatibility.

Upstream metadata

The following fields come from the pinned Redis metadata, not measured ffkv performance or an assertion that ffkv enforces every upstream flag. Running COMMAND INFO/COMMAND DOCS describe the current engine.

Upstream Redis complexity: O(1) for IFEQ/IFNE, O(N) for IFDEQ/IFDNE where N is the length of the string value.

Upstream arity: -2 (includes the command name; a negative number is a minimum).

Command flags: WRITE, FAST.

ACL categories: STRING.

Argument structure

Argument	Type	Constraints / metadata
key	key	key_spec_index: 0
condition	oneof	optional
↳ ifeq-value	string	token: IFEQ
↳ ifne-value	string	token: IFNE
↳ ifdeq-digest	string	token: IFDEQ
↳ ifdne-digest	string	token: IFDNE

Key specifications

Upstream key discovery descriptors (indexes are relative to the full command vector):

[
  {
    "flags": [
      "RW",
      "DELETE",
      "VARIABLE_FLAGS"
    ],
    "begin_search": {
      "index": {
        "pos": 1
      }
    },
    "find_keys": {
      "range": {
        "lastkey": 0,
        "step": 1,
        "limit": 0
      }
    }
  }
]

Additional pinned upstream metadata

{
  "group": "string",
  "since": "8.4.0"
}

Metadata source · Local snapshot: src/command_metadata.json, key delex.

BDD coverage and source examples

These are source observations, not a test run performed by this documentation build. A tag identifies scenario intent; an extracted vector identifies a command invocation, which may intentionally produce an error. Scenarios may require setup, multiple connections, persistence, cluster nodes or native-module fixtures.

• Conditional deletion cannot remove a changed value — tests/bdd/features/strings.feature:117; command tag and invocation observed.
• Value comparisons are binary safe and digest equality can delete a key — tests/bdd/features/strings.feature:952; command tag and invocation observed.
• Resolved multi string writes survive crash recovery with their expiration — tests/bdd/features/strings.feature:1043; command tag and invocation observed.
• String type errors never destroy a collection (Scenario Outline) — tests/bdd/features/strings.feature:1139; command tag and invocation observed.

Extracted command vectors

The following JSON arrays are the test harness’s argument vectors, not shell commands. Numeric arguments are converted by the harness; objects of the form {"base64":"…"} represent decoded binary bytes, not a literal JSON command argument. Preserve scenario setup and connection ordering. See the CLI guide for shell quoting and binary stdin. No reply is invented or inferred.

Conditional deletion cannot remove a changed value — tests/bdd/features/strings.feature:147 (I execute:)

[
  "DELEX",
  "state"
]

Next source assertion: the reply equals:

0

Resolved multi string writes survive crash recovery with their expiration — tests/bdd/features/strings.feature:1057 (I execute:)

[
  "DELEX",
  "delete-me",
  "IFEQ",
  "old"
]

Next source assertion: the reply equals:

1

Value comparisons are binary safe and digest equality can delete a key — tests/bdd/features/strings.feature:986 (I execute:)

[
  "DELEX",
  "digest-delete",
  "IFDEQ",
  "B6ACB9D84A38FF74"
]

Next source assertion: the reply equals:

1