Okay, another question from Twitter (original content will have to wait till I get some more free time!)

Here’s the challenge:

Need help with #Azure #AppInsights: when summarizing, I want to adjust the bin size according to the time range the user selects in the Query editor. I found `bin_auto(timestamp)` which looks promising, but still I need to `set query_bin_auto_size=1m` manually. Any clues? pic.twitter.com/TtwCTH5OtR

— Torben Knerr (@tknerr_de) February 8, 2019

So what we need to do here is somehow infer the time-range of the query, and then create a fixed set of time bins according to that range.

I think the only way to that is by performing 2 queries – one to get the time range and convert it into a fixed interval, and a second query with the actual logic.

To convert the result of the first query into a ‘variable’ we can use in the second query, I’ll use the ‘toscalar‘ operation.

Here we go:

let numberOfBuckets = 24;
let interval = toscalar(requests
| summarize interval = (max(timestamp)-min(timestamp)) / numberOfBuckets
| project floor(interval, 1m));
requests
| summarize count() by bin(timestamp , interval)

I use ‘floor’ here just to round the interval and make the results a bit more readable.