I have this query:
select * from topics
order by case when id=1 then 0 else 1 end, bumped_at desc
limit 30
It works fine, bumps id 1 to the front of the sort fine but is
terribly inefficient and scans
OTH
"select * from topics where id = 1" is super fast
"select * from topics order by bumped_at desc limit 30" is super fast
Even this is fast, and logically equiv as id is primary key unique
select * from topic
where id = 1000
union all
select * from (
select * from topics
where id <> 1000
order by bumped_at desc
limit 30
) as x
limit 30
However, the contortions on the above query make it very un-ORM
friendly as I would need to define a view for it but would have no
clean way to pass limits and offsets in.
Is there any clean technique to bump up particular rows to the front
of a sort if a certain condition is met without paying a huge
performance hit?
