extent_id()
Returns a unique identifier that identifies the data shard ("extent") that the current record resides in.
Applying this function to calculated data that isn't attached to a data shard returns an empty guid (all zeros).
Syntax
extent_id()
Returns
A value of type guid that identifies the current record's data shard,
or an empty guid (all zeros).
Example
The following example shows how to get a list of all the data shards
that have records from an hour ago with a specific value for the
column ActivityId. It demonstrates that some query operators (here,
the where operator, and also extend and project)
preserve the information about the data shard hosting the record.
T
| where Timestamp > ago(1h)
| where ActivityId == 'dd0595d4-183e-494e-b88e-54c52fe90e5a'
| extend eid=extent_id()
| summarize by eid
This capability isn't supported in Azure Monitor