Copy a table from one database to another in Postgres

Solution 1:

Extract the table and pipe it directly to the target database:

pg_dump -t table_to_copy source_db | psql target_db

Note: If the other database already has the table set up, you should use the -a flag to import data only, else you may see weird errors like "Out of memory":

pg_dump -a -t table_to_copy source_db | psql target_db

Solution 2:

You can also use the backup functionality in pgAdmin II. Just follow these steps:

• In pgAdmin, right click the table you want to move, select "Backup"
• Pick the directory for the output file and set Format to "plain"
• Click the "Dump Options #1" tab, check "Only data" or "only Schema" (depending on what you are doing)
• Under the Queries section, click "Use Column Inserts" and "User Insert Commands".
• Click the "Backup" button. This outputs to a .backup file
• Open this new file using notepad. You will see the insert scripts needed for the table/data. Copy and paste these into the new database sql page in pgAdmin. Run as pgScript - Query->Execute as pgScript F6

Works well and can do multiple tables at a time.

Solution 3:

Using dblink would be more convenient!

truncate table tableA;

insert into tableA
select *
from dblink('hostaddr=xxx.xxx.xxx.xxx dbname=mydb user=postgres',
            'select a,b from tableA')
       as t1(a text,b text);

Solution 4:

Using psql, on linux host that have connectivity to both servers

( export PGPASSWORD=password1 
  psql -U user1 -h host1 database1 \
  -c "copy (select field1,field2 from table1) to stdout with csv" ) \
| 
( export PGPASSWORD=password2 
  psql -U user2 -h host2 database2 \ 
   -c "copy table2 (field1, field2) from stdin csv" )