I like some functions of influxDB that's why I would like to use it instead of just MySQL etc.
In my case I need to pull from the DB exactly the same time series I pushed into it and any data change between what I put and what I got is considered a data corruption.
Is it possible to disable downsampling in InfluxDB?
as per documentation
these are features: Continuous Queries (CQ) and Retention Policies (RP) but they are not optional and forced to be used. Am I right? or there is a way of turning these things off?
Is there any other time series database that supports statistical functions and works with Grafana but does not have downsampling (or it is optional)?
Continuous Queries (CQ) and Retention Policies (RP) are optional. You don't need to use them. You can use default retention policy named autogen which has infinite retention and you can keep data with original granularity forever (= unless you will reach some resource limits - disk/memory/response times/...).