Hi,
I have a table establishment which contains these columns: id, name, longitude, latitude.
I want to select all the establishments in the table establishment within a radius from a reference point which is a given establishment.
For example:
I have a given establishment called establishment1 and has an id=1.
I want to display all the establishments within a radius 1km from this establishment.
I wrote this query:
select
e.name,
e1.name, e1.longitude, e1.latitude
from establishment as e, establishment as e1
where
e.id = 1
and
e.id <>
e1.id and ST_DWithin(ST_SetSRID(ST_MakePoint(e1.longitude, e1.latitude), 4326),ST_MakePoint(e.longitude, e.latitude)::geography, 1000) ;
Is it a good practice to iterate the rows of the table like I did and does not have an effect in the performance if the number of table's rows increase?
