备份 AWS RDS Postgres 实例中的特定表

Question

I have two databases on Amazon RDS, both Postgres. Database 1 and 2

I need to restore an instance from a snapshot of Database 1 for my Staging environment. (Database 2 is my current Staging DB).

However, I want the data from a few of the tables in Database 2 to overwrite the tables in the newly restored snapshot. What is the best way to do this?

Answer 1

When restoring RDS from a Snapshot, a new database instance is created. If you only wish to copy a portion of the snapshot:

• Restore the snapshot to a new (temporary) database
• Connect to the new database and dump the desired tables using pg_dump
• Connect to your staging server and restore the tables using pg_restore (most probably deleting any matching existing tables first)
• Delete the temporary database

pg_dump actually outputs SQL commands that are then used to recreate tables and restore data. Look at the content of a dump to understand how the restore process actually works.

Answer 2

I hope this still works for someone else.

With my team we faced a similar issue. We also had 2 Postgres databases and we also just needed to backup some tables from db1 to db2.

What we did is to use a lambda function using Python (from AWS lambda ofc) that connected to both databases and validates if db1.table1 has the same data as db2.table1 , if not, then the lambda function should write the missing data from db1.table1 into db2.table1 . The approach of using lambda was because we wanted to automate the process due to the main db (let's say db1 ) is constantly being updated. In addition, it allowed us to only backup our desired tables (let's say 3 tables out of 10), instead of backing up the whole database.

Note: Maybe you want to do these writes using temporary tables to avoid issues with any constraints you have in your tables.