issue_comments: 970738130

I came up with the following query which seems to work!

sql with cte as ( select rowid, country, country_long, name, owner, primary_fuel from [global-power-plants] ), truncated as ( select null as _facet, null as facet_name, null as facet_count, rowid, country, country_long, name, owner, primary_fuel from cte order by rowid limit 4 ), country_long_facet as ( select 'country_long' as _facet, country_long as facet_name, count(*) as facet_count, null, null, null, null, null, null from cte group by facet_name order by facet_count desc limit 3 ), owner_facet as ( select 'owner' as _facet, owner as facet_name, count(*) as facet_count, null, null, null, null, null, null from cte group by facet_name order by facet_count desc limit 3 ), primary_fuel_facet as ( select 'primary_fuel' as _facet, primary_fuel as facet_name, count(*) as facet_count, null, null, null, null, null, null from cte group by facet_name order by facet_count desc limit 3 ) select * from truncated union all select * from country_long_facet union all select * from owner_facet union all select * from primary_fuel_facet (Limits should be 101, 31, 31, 31 but I reduced size to get a shorter example table).

Results look like this:

_facet | facet_name | facet_count | rowid | country | country_long | name | owner | primary_fuel -- | -- | -- | -- | -- | -- | -- | -- | --   |   |   | 1 | AFG | Afghanistan | Kajaki Hydroelectric Power Plant Afghanistan |   | Hydro   |   |   | 2 | AFG | Afghanistan | Kandahar DOG |   | Solar   |   |   | 3 | AFG | Afghanistan | Kandahar JOL |   | Solar   |   |   | 4 | AFG | Afghanistan | Mahipar Hydroelectric Power Plant Afghanistan |   | Hydro country_long | United States of America | 8688 |   |   |   |   |   |   country_long | China | 4235 |   |   |   |   |   |   country_long | United Kingdom | 2603 |   |   |   |   |   |   owner |   | 14112 |   |   |   |   |   |   owner | Lightsource Renewable Energy | 120 |   |   |   |   |   |   owner | Cypress Creek Renewables | 109 |   |   |   |   |   |   primary_fuel | Solar | 9662 |   |   |   |   |   |   primary_fuel | Hydro | 7155 |   |   |   |   |   |   primary_fuel | Wind | 5188 |   |   |   |   |   |  

This is a neat proof of concept.