Virtual fields in the console

The concept is covered in virtual fields. This page is the console workflow.

1. 1

   Write the extend in Explore

   Get the expression right against real data first. It is much easier to debug as a query line than as a saved definition.

2. 2

   Promote it

   With the cursor on the extend line, hit Save as field. The name defaults to the alias you used.

3. 3

   Use it everywhere

   It appears in the fields rail with a small ƒ marker, and completes in the editor like any other field.

1['api-gateway-prod']
2| extend is_slow = latency > 1000
3| summarize slow = countif(is_slow), total = count() by service
4| extend slow_pct = round(100.0 * slow / total, 1)
5| order by slow_pct desc