I believe this situation was caused after importing tags from an XML file in the Ignition designer.
Prior to importing the tag XML file, there had already been a table: sqlt_data_1_2017_11. After importing the tags XML file, a new table was created: sqlt_data_3_2017_11. There was no table: sqlt_data_2_2017_11.
We do this operation all the time and I have never seen this behavior. Not sure why a new table was created at all, and then to skip “2” was even stranger. What tipped this off was that we had new data being collected, yet when looking at our Ignition project windows I was not seeing the new data. I later found the reason was that it was being stored in sqlt_data_3_2017_11, while historical queries running in our Ignition project were still going against the table sqlt_data_1_2017_11. Therefore the last record we would get when looking at our Ignition project windows was the last record that was stored in the table sqlt_data_1_2017_11.
This was seen at a new installation at a customer site and I had remote access to the system. Since the customer did not mind losing data, I sopped the Ignition Gateway, deleted all Ignition historian tables (all sqlt… tables) and restarted the Gateway and all tables were recreated and the system was working fine.
But I am afraid this can happen again and am wondering if anyone else has seen this issue, or can give a possible explanation for what happened with the new partition table?
Historical tag provider options:
Partition Lenth: 1
Partition Units: Months
Enable Pre-processed Partitions: No
Enable Data Pruning: No