I am using DBeaver to query a PostgreSQL database.
I have this query, it simply selects the highest id per Enterprise_Nbr. The query works but is really slow. Is there any way I can rewrite the query to improve performance.
I am using the querytool DBeaver because I don’t have direct access to PostgreSQL. The ultimate goal is to link the PostgreSQL with PowerBi.
select *
from public.address
where "ID" in (select max("ID")
from public.address a
group by "Enterprise_Nbr")
>Solution :
Queries for greatest-n-per-group problems are typically faster if done using Postgres’ proprietary distinct on () operator
select distinct on ("Enterprise_Nbr") *
from public.address
order by "Enterprise_Nbr", "ID" desc;