backup-and-recoverylisted

PostgreSQL's backup + point-in-time recovery — `pg_basebackup` + WAL archiving (archive_command / archive_library) + `restore_command` + `pg_wal_replay_*` targets + the pg_backup_start/stop API + `pg_receivewal`. Covers `src/backend/backup/` (basebackup server code) + `src/backend/postmaster/pgarch.c` (archiver aux process) + `src/backend/access/transam/xlogrecovery.c` (recovery driver). Loads when the user asks about how base backups work, WAL archiving vs streaming replication, PITR targets (`recovery_target_*`), `pg_backup_start`/`pg_backup_stop` low-level API, `.backup` files, restore_command semantics, or incremental backup (PG 17+ with `WAL_SUMMARIZED`). Skip when the ask is about `pg_dump` (logical dump — different tool) or about physical replication streaming (`physical-replication` — related but sibling).
matejformanek/postgres-claude · ★ 0 · API & Backend · score 70

Install: claude install-skill matejformanek/postgres-claude

# backup-and-recovery — base backup + WAL archiving + PITR PG's backup strategy is TWO PARTS: 1. **Base backup** — a full copy of the data directory at a point in time. Made by `pg_basebackup` (client) which drives the server's basebackup code, OR by filesystem-level tools + `pg_backup_start` / `pg_backup_stop`. 2. **WAL archive** — every WAL segment shipped to secondary storage as it fills. Enables replay from the base backup to any later LSN. Together: recovery starts from base backup + replays WAL up to the desired point (crash-recovery-latest, specific LSN, specific time, specific named restore point). ## The file map ### Backup (primary side) | File | Role | |---|---| | `src/backend/backup/basebackup.c` | Server-side base-backup driver — walks the data directory, streams files to client, coordinates checkpoint. | | `src/backend/backup/basebackup_copy.c` | Copy protocol integration. | | `src/backend/backup/basebackup_gzip.c` / `_lz4.c` / `_zstd.c` | On-the-fly compression variants. | | `src/backend/backup/basebackup_target.c` | Where to write — client stream vs server-side path. | | `src/backend/backup/basebackup_incremental.c` | (PG 17+) Incremental backup driver — uses WAL summary files. | | `src/backend/backup/basebackup_progress.c` | Progress reporting via pgstat_progress_backup. | | `src/backend/backup/basebackup_server.c` | Server-side backup target — writes to a filesystem path directly, not client-stream. | | `src/backend/postmaster/pgarch.c` | The archiver