An illustrative data structure is provided using a structured table that uses a split primary key including a first key, referred to as a partition key, and a second key, referred to as a row key, along with a timestamp key, but that does not otherwise utilize uniform columns that can be used as a key. The partition key that is utilized is unusually fine in that it consists of an individual user identifier that is unique to the system and/or across multiple systems used in an enterprise. Additionally, the system can limit access to one session per individual partition key.