[Lens] Confusing behavior with mismatched index patterns

[AlonaNadler]

Edit:

Lens allows users to configure a chart for one index pattern, and then look at the fields list for a new index pattern without updating the chart.

There are several open questions:

• Should the difference in behavior in the left and right side index pattern switchers be more obvious to users?
• Should the left side index pattern switcher start implementing a "replace" behavior instead of a "look" behavior?
• Should users be allowed to get suggestions based on fields from a non-matching index pattern?

---

Kibana version: master

I switched from a time series chart to a table, I tried to override the timestamp without another dimension or even add another dimension. Lens doesn't allow to drop the field.
Expected:

• Lens should allow overriding a dimension field with another
• Lens should allow adding another dimension as a column

I dropped the field in the preview. It replaced the existing timestamp dimension and replaced the two metrics with count
expected:

• current metrics stay and the new field is added either as a dimension or as another metric column

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[wylieconlon]

@AlonaNadler This is working as intended, so it's not a bug. I'm going to update the title and description to clarify that this is "confusing behavior", but that we need to do some UX brainstorming to come up with alternatives.

The steps you listed were incomplete. Based on the gif, I know that you did the following:

1. Configure a chart using metricbeat-* data
2. Use the left side index pattern switcher to look at logs-*. During the beta period, we called this "looking at an index" vs "switching the visualization"
3. You dragged a field from logs-* to a visualization using metricbeat-* and got no suggestions, which is working as expected.

If you had switched the index pattern using the right side switcher, instead of the left side switcher, this would have worked as expected. Alternatively, if you had skipped step 1 of configuring a chart, the left side switcher would have updated the index pattern in both places.

Why is this the current behavior?

The left and right index pattern switchers behave the same when the chart is empty. When there is a single-layer chart configured, the left side switcher will stop replacing the existing chart when you change to a different index pattern, because it lets them "look around". The right side switcher will always replace the configuration when you switch index patterns, and sometimes it will "lose" your configuration, which we thought was too destructive to ship to users.

[stratoula]

I think that by moving the dataview switcher to the unified search has improved the experience here