CODEWITHSUNDEEP
ruby-on-railsnode.jspostgresql
Baub
Baub

Reputation: 5044

Postgres Migrate Data To New Database

I have two Postgres databases, one old and one new.

How do I move the data from old to new while keeping the existing data that's in new (and of course the data that's being migrated from old) in tact? Also, what if I want to add mappings from old table names to new table names?

Taking both databases offline is a possibility, if truly necessary.

Upvotes: 0

Views: 195

Answers (1)

Patrick Narkinsky
Patrick Narkinsky

Reputation: 561

Check out the --data option to pg_dump. This should produce a dump that won't drop or recreate tables or overwrite existing data.

Something like:

pg_dump --data database_name > dump.sql

This can be restored to the database using something like:

psql database_name << dump.sql

I'd be very careful using this if you have important data in "new", and I'd make sure I had a dump of the new database (with schema included, not just data) in case I messed it up.

NOTE: you tagged this with rails, so be aware that this approach will bypass any ActiveRecord validations you have (including validations for uniqueness, etc.

Upvotes: 1

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