What's the best way to copy a subset of a table's rows from one database to another in Postgres?

Question

I\'ve got a production DB with, say, ten million rows. I\'d like to extract the 10,000 or so rows from the past hour off of production and copy them to my local box. How do I do

Answer 1

Source:

psql -c "COPY (SELECT * FROM mytable WHERE ...) TO STDOUT" > mytable.copy

Destination:

psql -c "COPY mytable FROM STDIN" < mytable.copy

This assumes mytable has the same schema and column order in both the source and destination. If this isn't the case, you could try STDOUT CSV HEADER and STDIN CSV HEADER instead of STDOUT and STDIN, but I haven't tried it.

If you have any custom triggers on mytable, you may need to disable them on import:

psql -c "ALTER TABLE mytable DISABLE TRIGGER USER; \
         COPY mytable FROM STDIN; \
         ALTER TABLE mytable ENABLE TRIGGER USER" < mytable.copy