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question: how does pgbackrest do incremental backup right now if postgres doesn't yet support it ?
by lucw 3y ago
question: how does pgbackrest do incremental backup right now if postgres doesn't yet support it ?
- deleted 3y ago[deleted]
- pilif 3y agoBy keeping the whole WAL. The incremental backup would be just the WAL segments excluding the base backup. With this new feature, the WAL segments you need to store are much, much smaller.
- aflukasz 3y ago> By keeping the whole WAL. Not exactly. Pgbackrest can do incremental backups that are restored by applying file system level diffs (stored in incremental backup) to the base backup. WALs are only involved at the very last step when restore process is finalized by applying WALs that were generated during BACKUP step itself. But that's not pgbackrest limitation, that's how any Postgres restore process works. EDIT: "how any Postgres restore process works" that restore a backup done from a live database that is being written to when backup is taking place.
- brand 3y agopgbackrest works purely at the file level, by looking at checksums. It’s rather primitive by comparison.
- aflukasz 3y agoAt filesystem level, yes, but worth noting that since v2.46 (from May 2023) it can also work with block level granularity: https://pgbackrest.org/configuration.html#section-repository/option-repo-block https://pgbackrest.org/configuration.html#section-repository...