How can we make pg_dump and pg_restore 5 times faster?
pg_dump and pg_restore are reliable tools for backing up and restoring Postgres databases. They're essential for database migrations, disaster recovery and so on. They offer precise control over object selection for backup/restore, dump format options (plain or compressed), parallel table processing and so on. They ensure a consistent database snapshot is dumped and restored.
However, they are single-threaded at the table level. This significantly slows down the dump and restore of databases with a star schema common in real-world applications such as Time series and IoT. For databases over 1 TB, pg_dump and pg_restore can take days, increasing downtime during migrations and RTOs in disaster recovery scenarios.
In this blog, we'll discuss an idea called "Parallel Snapshotting". This idea could be integrated into Postgres upstream in the future to make pg_dump and pg_restore parallelizable at a single table level. Parallel Snapshotting has already been implemented in PeerDB, an open-source Postgres replication tool. We will also cover a few interesting benchmarks of migrating a large table of 1.5TB from one Postgres Database to another with and without Parallel Snapshotting.
pg_dump is the most reliable way to back up a PostgreSQL database. It enables the backup of a database at a consistent snapshot; that is, the backup guarantees a state that existed previously. The backup generated by pg_dump is a logical representation of the data in PostgreSQL, not a copy of the PostgreSQL data directory. It captures objects as they appear in PostgreSQL.
