Reshape array in PostgreSQL
Something like this should work:

update the_table 
  set data = x.data
from (
  select t.id, array_agg(d.x order by d.idx) as data
  from the_table t, unnest(data) with ordinality as d(x, idx)
  group by t.id
) x
where x.id = the_table.id;


Sample psql output:

postgres=&gt; create table the_table (id integer primary key, data double precision[]);
CREATE TABLE
postgres=&gt; insert into the_table values
postgres-&gt;   (1, '{{2.20751909662576},{2.20679071024511},{2.20615506273571},{2.2055910715332},{2.20507756148068},{2.20459435596551},{2.20412336646322},{2.20364958013081}}'),
postgres-&gt;   (2, '{{2.19780662274576},{2.19740415504621},{2.19705997866427},{2.19677947299938},{2.1965673849541},{2.19642825612809},{2.1963668334181}}');
INSERT 0 2
postgres=&gt; select *
postgres-&gt; from the_table;
 id |                                                                           data
----+----------------------------------------------------------------------------------------------------------------------------------------------------------
  1 | {{2.20751909662576},{2.20679071024511},{2.20615506273571},{2.2055910715332},{2.20507756148068},{2.20459435596551},{2.20412336646322},{2.20364958013081}}
  2 | {{2.19780662274576},{2.19740415504621},{2.19705997866427},{2.19677947299938},{2.1965673849541},{2.19642825612809},{2.1963668334181}}
(2 rows)

postgres=&gt; update the_table
postgres-&gt;   set data = x.data
postgres-&gt; from (
postgres(&gt;   select t.id, array_agg(d.x order by d.idx) as data
postgres(&gt;   from the_table t, unnest(data) with ordinality as d(x, idx)
postgres(&gt;   group by t.id
postgres(&gt; ) x
postgres-&gt; where x.id = the_table.id;
UPDATE 2
postgres=&gt; select *
postgres-&gt; from the_table;
 id |                                                                   data
----+------------------------------------------------------------------------------------------------------------------------------------------
  1 | {2.20751909662576,2.20679071024511,2.20615506273571,2.2055910715332,2.20507756148068,2.20459435596551,2.20412336646322,2.20364958013081}
  2 | {2.19780662274576,2.19740415504621,2.19705997866427,2.19677947299938,2.1965673849541,2.19642825612809,2.1963668334181}
(2 rows)

postgres=&gt;