Did You Know? SQLTags Historian Makes Storing and Charting Historical Data Fast, Efficient, and Easy
03/09/2010 - Logging process data for the purposes of charting and reporting has long been, and continues to be, one of the most popular uses of Inductive Automation's software. For our new release, Ignition by Inductive Automation, we've introduced a feature called SQLTags Historian that makes storing and charting history faster, more efficient, and easier than ever before.

SQLTags Historian builds on the success of our SQLTags realtime tag database system. There are only two steps to using the SQLTags Historian. First, you must configure a connection to a supported database, such as MySQL, SQL Server, or Oracle. Second, you simply select the "Store History for this Tag" option on any of your tags. That's it—SQLTags Historian creates and manages the tables needed to efficiently store history automatically. You're now storing tag history to your database.

Not only is SQLTags Historian easy to set up, but it is very efficient as well. It only stores tag values when they change outside of a deadband. Tags that aren't changing don't take up any storage space in the database. You also can control how frequently a tag is sampled when it is changing through the use of a historical scan class. Scan classes let you choose different logging intervals for sets of tags, or even alter the logging rate dynamically, storing high resolution history only when it is needed. The historian system will also automatically partition your data into multiple tables in the database. This partitioning feature accomplishes two important functions: ensuring consistently high-performance over the long term, and providing an extremely convenient mechanism for data archival and pruning.

One of the best parts about data stored using the SQLTags Historian is that using the data requires no knowledge of the SQL language. Querying history is a matter of specifying a list of tags, a range of time, and a resolution. Even easier, just drag and drop a historian-enabled tag onto an Easy Chart, and the chart will be configured with a SQLTags Historian pen for that tag. Using this drag-and-drop configuration is a great way to rapidly create an advanced, web-launched SCADA system with minimal effort. If you haven't already, download Ignition today and give it a try; you'll be glad you did.