ZSET.F64

Sets a key to a double-precision floating-point value in the ZMap ordered key-value store.

Syntax

ZSET.F64 <key> <value> [NAMESPACE <path>]

Arguments

key and value are positional. NAMESPACE is a keyword argument and comes after them.

Argument	Type	Required	Description
key	bytes	Yes	The key to set.
value	double	Yes	A finite IEEE-754 double-precision value.
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

ZSET.F64 writes a typed 64-bit floating-point value for a key in the ZMap subspace of the session’s current namespace. The value is encoded as 8 bytes in little-endian IEEE-754 double format, the same encoding used by ZINC.F64 and read by ZGET.F64.

If the key already exists, its value is overwritten silently.

The value must be a finite double. NaN and Infinity are rejected. Negative zero (-0.0) is normalized to 0.0.

The command supports two transaction modes:

• Auto-commit (one-off): When no explicit transaction is active, Kronotop creates a transaction, performs the write, and commits it immediately. This is the default mode.
• Explicit transaction: When a BEGIN has been issued, the write is staged in the current transaction and only persists 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 'ZSET.F64' command	-
ERR	value is not a double or out of range	-
ERR	Invalid value: must be a finite IEEE-754 double	The value is NaN or Infinity.
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

Set a floating-point value:

> ZSET.F64 price 19.99
OK

> ZGET.F64 price
(double) 19.99

Overwrite an existing value:

> ZSET.F64 price 19.99
OK

> ZSET.F64 price 24.99
OK

> ZGET.F64 price
(double) 24.99

NaN rejection:

> ZSET.F64 price NaN
(error) ERR Invalid value: must be a finite IEEE-754 double

Use within an explicit transaction:

> BEGIN
OK

> ZSET.F64 tx-price 42.42
OK

> COMMIT
OK

> ZGET.F64 tx-price
(double) 42.42