Historian sql_data_ explain t_stamp
I am trying to query the history database and I need to know some things about this.
What does the bigint t_stamp represent? How do I convert this into a date/time value?
Also, how often does this table update? Is this updated every change, every scan class interval, or ever scan class interval with a change from the previous value.
The timestamp value in the SQLTags History tables are stored in Unix Time. It’s the number of milliseconds since January 1, 1970 00:00:00
To convert the timestamp, take a look at our knowledge base article here:
http://inductiveautomation.com/support/kb/142
As far as storing values, it depends on how you set everything up. The default is to store a value at every scanclass execution providing the value has changed since the last execution.
Hope this info was helpful.