Postgres 10

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

create table tbl(

store_visited text,

virtual_time timestamp);

insert into tbl values

('M&S','2017-09-16 17:52:06'),('WholeFoods','2017-09-16 18:26:17'),

('WholeFoods','2017-09-16 18:26:19'),('WholeFoods','2017-09-16 18:26:20'),

('OysterRooms','2017-09-18 13:31:39');

select * from tbl;

5 rows affected

select

store_visited,

virtual_time

from

(select

store_visited,

virtual_time,

row_number() over(partition by store_visited order by virtual_time asc) as vt

from

tbl) as new

where

vt = '1'

order by

virtual_time;