zhukang 1c7abd81d1 All 310 Manus skill-hub community skills as a Kortix marketplace registry

- 310 registry:skill items, 1528 files, 7 categories (hub tags)
- registry.json generated by @kortix/registry buildRegistry
- nested SKILL.md in sn-da-* renamed SUBSKILL.md (no phantom skills)
- provenance + licenses: SOURCES.md

2026-09-15 13:37:20 +08:00

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title	description	tags
Backup and Recovery	Logical/physical backups, PITR, WAL archiving, backup tools, and recovery strategies	postgres, backup, recovery, pitr, pg_dump, pg_basebackup, wal-archiving, operations

Backup and Recovery

FUNDAMENTAL RULE: Backups are useless until you've successfully tested recovery.

Logical Backups (pg_dump)

Exports as SQL or custom format; portable across PG versions and architectures. Formats: -Fp (plain SQL), -Fc (custom compressed, selective restore), -Fd (directory, parallel with -j), -Ft (tar, avoid). Use -Fd -j 4 for large DBs. Restore: pg_restore -d dbname file.dump; add -j for parallel restore. Selective table restore: pg_restore -t tablename. Slow for large DBs; RPO = backup frequency (typically 24h).

Physical Backups (pg_basebackup)

Copies raw PGDATA; same major version and platform required; cross-architecture works if same endianness (e.g., x86_64 ↔ ARM64). Faster for large clusters; includes all databases. Flags: -Ft -z -P for compressed tar with progress. Manual alternative: pg_backup_start() → copy PGDATA → pg_backup_stop() (complex; must write returned backup_label).

PITR (Point-in-Time Recovery)

Requires base backup + continuous WAL archiving. Restores to any timestamp, transaction, or named restore point. Without PITR: restore only to backup time (potentially lose hours). With PITR: RPO = minutes. archive_command must return 0 ONLY when file is safely stored—premature 0 = data loss risk. wal_level must be replica or logical (not minimal).

WAL Archiving

archive_mode=on, archive_command='test ! -f /archive/%f && cp %p /archive/%f'. Test archive command as postgres user (not root) since permission issues are common. Monitor pg_stat_archiver for failed_count, last_archived_time. Archive failures prevent WAL recycling → disk fills.

Tool Comparison

Tool	Use case
pg_dump	Small DBs, migrations, selective restore
pg_basebackup	Basic PITR, built-in
pgBackRest	Production—parallel, incremental, S3/GCS/Azure, retention
Barman	Enterprise PITR, retention policies
WAL-G	Cloud-native, S3/GCS/Azure

RPO/RTO

Logical only: RPO = backup interval (hours); RTO = hours. PITR: RPO = minutes; RTO = hours. Synchronous replication: RPO = 0; RTO = seconds to minutes (failover).

Operational Rules

Verify integrity with pg_verifybackup (PG 13+)
Test recovery / PITR regularly
Take backups from standby to avoid impacting primary
Retention: 7 daily, 4 weekly, 12 monthly
Monitor archive growth and backup age
Never assume backups work without testing

2.6 KiB Raw Blame History