e.g. I have data set that belong 2010-2018.
from 2010 till 2016 retention policy maintain every 5 minutes data points
if I change retention policy in 2017 till 2018 like this: retention policy maintain every 1 minutes data points. now I want to know what exactly happen:
1-How it will show on Grafana? (as I mention from 2010-2016 we have lower data points and in 2017-2018 these points increase.)
2-Influx create new measurement(s) to store these data or write them in same measurement?
That’s not exactly how retention policies function. A retention policy governs how long data is stored in a given database. If you set a retention policy of 1 year, only data < 1year will be retained. It is not in any way related to the frequency of the datapoint.
In order to do what I think you’re asking about, you would want to downsample your data to a lower frequency – the 5 minute data points – and save those in a NEW database with a longer retention policy. You can reference this document for more information: Downsampling and data retention | InfluxDB OSS 1.7 Documentation