Show which pool each query response row came from

[philrz]

At the time this issue is being opened, Zui is at commit 4518517.

Community user @SoftTools59654 made the following feature suggestion originally in #2924:

When the command from * is used for general search of all files
When the item is found. It is not possible to find out which pool this found data belongs to
If there is an option to show which pool the found data belongs to, I think it would be appropriate

We discussed it as a group and unfortunately the way Zed works today this is not trivial to design for the general case, so we may not be able to deliver it soon. However we'll hold the issue open to help gather interest.

That said, it's understandable why users would want to see this. While it might be ideal if the system had an option to add this detail automatically, users could take steps on their own to provide this detail by leveraging the existing data model.

For instance, if working in Zui like below, a Shaper could be used to add an additional field as data is being loaded to indicate the pool name, allowing that field to be observed later when needed. This would be even easier if loading was being done at the shell using zq and zed commands, e.g., a wrapper script for loading data could have the pool name defined once and provide it a put to add the field and also reference that same pool name in zed create and zed use to reference that pool by name.

Demo.mp4

@nwt noted a different approach like the one below could potentially add this detail at query time once we've implemented brimdata/super#4752.

op my_from(pool): ( from pool | yield {this, pool} )

from :pools | my_from(this)