Suggerirei di memorizzare l'intero poligono come tipo di geometria. Se/quando è necessario "convertirlo" in geografia, utilizzare i metodi geografici STNumPoints e STPointN per estrarre i singoli punti in sequenza e convertirli in modo appropriato.
A proposito di conversione, in che formato sono i tuoi dati adesso? Non vedo informazioni lat/long lì, ma forse mi sfugge qualcosa.
Modifica:ecco una soluzione che ho appena codificato.
use tempdb;
create table tally (i int not null);
with
a as (select 1 as [i] union select 0),
b as (select 1 as [i] from a as [a1] cross join a as [a2]),
c as (select 1 as [i] from b as [a1] cross join b as [a2]),
d as (select 1 as [i] from c as [a1] cross join c as [a2]),
e as (select 1 as [i] from d as [a1] cross join d as [a2])
insert into tally
select row_number() over (order by i) from e
create unique clustered index [CI_Tally] on tally (i)
create table ace (g geometry)
insert into ace (g)
values (geometry::STGeomFromText(<<your polygon string here>>, 0));
select i, g.STPointN(t.i), g.STPointN(t.i).STAsText()
from ace as [a]
cross join tally as [t]
where t.i <= g.STNumPoints()
