Base (abstract)

This abstract schema defines metadata and fields available to all neurarrow tables.

Parent schemas

None

Schema metadata

These metadata keys are defined in addition to those defined by any parent schemas.

Required schema metadata

These keys MUST exist in the schema’s metadata.

version

• encoding: UTF-8 string

The version of the neurarrow specification used to write the data.

context

• encoding: UTF-8 string

The identifier for the context shared by all elements in this file, and possibly other files too; see Contexts.

Optional schema metadata

These keys MAY exist in the schema’s metadata.

attr:*

• encoding: various

Unstructured arbitrary attributes beneath the attr: prefix. Nested attributes MAY be stored in a flat representation with : separators, e.g. attr:parent:child:key = value. However, storing a structure in a serialised form like JSON is also acceptable.

Fields

These fields are defined in addition to those defined by any parent classes.

Required fields

These fields MUST exist in the file.

• None

Optional fields

These fields MAY exist in the file.

attr

• data type: map with variable-length string keys and variable-length string values
• nullable: yes

Arbitrary attributes set on a per-row basis. Keys SHOULD NOT use the attr: prefix.

attr:*

• data type: various
• nullable: various

Arbitrary fields beneath the attr: prefix.

Derived fields

These fields MAY exist in the file, but MUST be calculable from other fields, and MAY be invalidated if the source fields are updated.

• None