ZDEL

Deletes a key from the ZMap ordered key-value store.

Syntax

ZDEL <key> [NAMESPACE <path>]

Arguments

key is positional. NAMESPACE is a keyword argument and comes after it.

Argument	Type	Required	Description
key	bytes	Yes	The key to delete.
NAMESPACE	string	No	Run this command in the given namespace instead of the session’s current one. The namespace must exist. The session’s current namespace does not change.

Return Value

Simple string: OK on success.

Behavior

ZDEL removes a key and its associated value from the ZMap subspace of the session’s current namespace, backed by FoundationDB.

The operation is idempotent: deleting a non-existent key returns OK without raising an error.

The command supports two transaction modes:

• Auto-commit (one-off): When no explicit transaction is active, Kronotop creates a transaction, performs the delete, and commits it immediately. This is the default mode.
• Explicit transaction: When a BEGIN has been issued, the delete is staged in the current transaction and only takes effect when COMMIT is called.

All data is scoped to a namespace: the session’s active one, or the one given with NAMESPACE. The same key in different namespaces refers to different entries.

Errors

Argument errors:

Error Code	Error message	Cause
ERR	wrong number of arguments for 'ZDEL' command	-
ERR	Unknown '<keyword>' argument	-
ERR	NAMESPACE argument must be followed by a namespace	-

Namespace errors:

Error Code	Error message	Cause
NOSUCHNAMESPACE	No such namespace: '<path>'	-
NAMESPACEBEINGREMOVED	Namespace '<path>' is being removed	-

Examples

Delete an existing key:

> ZSET mykey "Hello"
OK

> ZDEL mykey
OK

> ZGET mykey
(nil)

Delete a non-existent key:

> ZDEL nosuchkey
OK

Use within an explicit transaction:

> ZSET mykey "Hello"
OK

> BEGIN
OK

> ZDEL mykey
OK

> COMMIT
OK

> ZGET mykey
(nil)