Automated re-compression/average after a period of time
As a PI Administrator, currently there is no way to compress or average (then delete) your data automatically after an event reaches a certain age. It would be nice to have the ability to automatically compress or average specific tags after the events have existed for a certain period of times. For instance, I keep data for “Tag1” in 5 second intervals for 2 months. After 2 months, I average those events over 5 minute intervals and delete the 5-second interval data thereafter.
ADMIN RESPONSE
Aug 20, 2022
We currently have no plans to automatically recompress data without user intervention. Since automated recompression would delete data, we are reluctant to do that unless an administrator explicitly performs such operations.
Hi, can you provide more details on what you're trying to accomplish? Are you trying to minimize disk usage? Appreciate any additional information that you can provide.
Our customers want to minimize disk usage. There's a source SCADA system that has measurements of 10ms frequency. It stores 1-3 month of data. Sometimes they need to extract some of this data (e.g. after an incident), but after 3 months they can afford to store 10s averages.
If they decide to store this data in PI, they will have to choose between storing all data 10ms resolution and consume a lot of space, or store 10s average but lose the resolution.
Going further, for the future it would be great to have dynamic compression rate (many customers ask about it). E.g. if there's no big changes, the compression is higher, but if we start to see changes of more than certain magnitude, the compression turns off.
