Eu faço da seguinte forma:
1.criar despejo:
psql -h dbhost1 -d dbname -U dbuser -c "copy(SELECT language, title FROM cms_title WHERE language != 'en' AND title != 'Blog') to stdout" > dump.tsv`
2.importar dump:
psql -h dbhost2 -d dbname -U dbuser -c 'copy cms_title from stdin' < dump.tsv
Isso anexará os dados importados à tabela.
