# Overview

In our example, the Doc with the name "Certification/certification_2022_v1.txt" is stored in the "Certification" folder ("Certification/"):

  • The "storage_class" of the Doc is "access_optimized". This storage class is for frequently accessed data.
  • The Doc was last updated on the 28th of March 2022 at 12:27:49.687 p.m. GMT ("updated_ts": 1648470469.687").
  • The "status" of the Doc is "ok". The Doc was copied, the copy of the Doc was successfully attached to the Twin and is stored in the Twin's directory.
  • The "description" holds attributes of the Doc in form of key-value pairs.
Attribute Type Description
creation_certificate dictionary
Certificate generated automatically by the system upon sending a request to copy the Doc (attach_twin_doc endpoint). It cannot be modified after it has been generated.
Attribute Type Description
created_ts timestamp Time at which the Doc was created. Measured in seconds (to three decimal places) that have elapsed since the Unix epoch (opens new window).
creator string Account UUID of the Account creating the Doc.
hash * string SHA-256 hash (opens new window).
size integer Size of the Doc in bytes.
storage_class string, value can be "access_optimized" or "cost_optimized" Storage class of the Doc:
- "access_optimized": Storage class for frequently accessed data.
- "cost_optimized": Storage class for automatic cost savings for less frequently accessed data.
Once the Doc has been copied and attached to the Twin, the "storage_class" cannot be changed.
status string, value can be "copying", "ok", "error", or "hash_mismatch" Status of the Doc:
- "copying": The Doc is in the process of being copied.
- "ok": The copy of the Doc has been successfully generated. It is attached to the Twin and stored in the Twin's directory.
- "hash_mismatch": The "hash" provided in the request does not match the hash of the Doc. A copy of the Doc could not be generated.
- "error": An error occurred and a copy of the Doc could not be generated.
updated_ts timestamp Time at which the Doc was last updated. Measured in seconds (to three decimal places) that have elapsed since the Unix epoch (opens new window).
description dictionary User defined key-value pairs:
- key: It must match the regular expression (opens new window) ^[a-z_][0-9a-z_]{0,63}$.
- value: JSON compliant value.
For more details consult the description field section.

*

The "hash" attribute is only displayed in the "creation_certificate" if it was provided in the request to the attach_twin_doc endpoint.