can recs be transferred between DBs ?

psql (15.3, server 15.15) on linux

dvdb=# \d arch_restore
Table "misc.arch_restore"
Column | Type | Collation | Nullable | Default
--------+-------------------+-----------+----------+---------
pk | integer | | not null |
proj | character varying | | |
data | character varying | | |
Indexes:
"arch_restore_pkey" PRIMARY KEY, btree (pk)

dvdb=# select * from arch_restore order by pk;
pk | proj | data
----+-------+------------
1 | alpha | the_data_1
2 | alpha | the_data_2
3 | alpha | the_data_3
4 | beta | the_data_4
5 | beta | the_data_5
6 | beta | the_data_6
7 | gamma | the_data_7
8 | gamma | the_data_8
9 | gamma | the_data_9
(9 rows)

I decided that it's time to archive the 'beta' project. So I create a new
DB in the PG instance and put them all there leaving...

dvdb=# select * from arch_restore order by pk;
pk | proj | data
----+-------+------------
1 | alpha | the_data_1
2 | alpha | the_data_2
3 | alpha | the_data_3
7 | gamma | the_data_7
8 | gamma | the_data_8
9 | gamma | the_data_9
(9 rows)

And in the "beta_archive" DB I have the beta proj recs...

dvdb=# select * from arch_restore order by pk;
pk | proj | data
----+-------+------------
4 | beta | the_data_4
5 | beta | the_data_5
6 | beta | the_data_6
(9 rows)

The managers tell me that they want to restore "beta" back to the main DB.
I know I could do this with something like a perl script, making
connections to both DBs and transferring them over using select statements
in "beta_archive" and insert statements in the main DB. But is there a
better way, something inherent in PG SQL that allows me to do something
like this ?

Thanks in Advance