If your historian doesn't provide these key elements, you should consider switching to an alternate solution. If you haven't yet selected a historian, consider these key elements when choosing a historian.
Regardless of your choice in historians, your historian should be reliable. You should not have to question the data and there should not be data missing. If your data is in question, how can you be confident that any decisions you make based on your historical data will be correct?
Some historians use algorithms to average the data they store to decrease disk space. When values are averaged, resolution and accuracy are lost. Choose a historian that stores the raw data values and offers tools to return your data as raw or aggregated values.
If you can't get data from your historian in a timely manner you won't want to use it. Some historians use an underlying SQL database that is not optimized for time-series data. It may operate quickly when you are only storing small amounts of data, but larger amounts of data storage will slow it to a crawl. These databases often need purged to keep performance manageable, forcing you to discard historical records. Choose a historian that has been optimized for time-series data.
Some historians are so complicated they may require days of installation, setup, and training. After all of this, they may require constant monitoring and a database administrator to keep operations running smoothly. Historians are supposed to help you understand, improve, and simplify your processes; not consume even more resources. Choose a historian that has been built around simplicity to decrease your cost of ownership.
Disk storage is becoming less of a problem in today's modern society, but some historians can store only limited amounts of data without causing performance issues. Others may use lossy compression algorithms that do not maintain the highest level of data accuracy. Choose a historian can store years worth of data without ever needing to purge the data for performance reasons.