Transferring subsets of PostgreSQL data via CSV using PgAdmin

If you want to export a subset of data (rather than the entire database or table) in CSV format:

Export subset of data with PgAdmin

1. Click “Execute Arbitrary SQL queries” button
2. Type query that will generate the subset of data
   • eg. select * from users where id >= 433 and id <= 436;
3. Click “Execute query, write results to file” button (save file as temp.csv)

Import subset of data with psql (not supported in PgAdmin yet)

1. copy vitals from '/temp.csv' DELIMITERS';' CSV;

The import feature will be available in PgAdmin soon.

References

A more thorough article:  Importing CSV Files to PostgreSQL Databases