A useful record does not have to be one single document. In practice, the records of processing activities, policies, access concepts, provider documents, test protocols and training evidence may be linked. What matters is that a reviewer can understand the connection without an extensive search.
For each important activity, record at least the purpose and data categories, affected groups, systems and providers, access roles, protection needs, material risks, assigned safeguards, responsible persons and available evidence. Add implementation status, known exceptions, the date of the last review and the next control date.
The measures themselves must be described with enough precision. “Access protection exists” says very little. A more useful record explains which role may access which data, how access is granted and withdrawn, how privileged access is logged and when permissions are reviewed. Technical detail can be placed in an annex if the main record points to it clearly.