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CPG service users need a physical backup and continuing WAL stream without copying cluster-wide role data or planner statistics. Existing replication privileges expose the complete data directory and WAL. Add ycmdb.redacted_physical_backup, disabled by default. When enabled, allow mdb_admin members without full replication privileges to use a restricted subset of the physical replication protocol. Omit pg_authid, pg_statistic, and pg_statistic_ext_data storage from base backups and replace WAL records modifying that storage with equal-length XLOG_NOOP records. Preserving record lengths leaves LSNs and the rest of the stream unchanged. The format relies on the bootstrap relfilenumbers of the omitted catalogs. Interlock restricted senders with catalog rewrites and permanently disable the format after the first rewrite attempt. Replicate the disablement in a versioned XLOG_NOOP payload. Close a restricted sender after an error so that transaction cleanup cannot release the interlock and then reuse the connection. Require streamed WAL, reject incremental backups, and disallow restricted senders during recovery. Exercise the protocol restrictions, omitted files, recovery, continued streaming, and rewrite disablement in TAP.
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Summary
ycmdb.redacted_physical_backuprollout gatemdb_adminmembers without full replicationprivileges to take a redacted physical backup and consume its WAL stream
pg_authid,pg_statistic, andpg_statistic_ext_datastorageXLOG_NOOPrecords, preserving LSNs and the remaining stream
The service creates a persistent physical slot and restores the omitted
catalogs from trusted storage before starting PostgreSQL from the backup.
The GUC is latched when a replication connection starts, so rollout or
rollback requires reconnecting the client. Incremental backups and embedded
WAL are intentionally outside format version 1.
Validation
make -j12 -ssrc/bin/pg_basebackupTAP suite: 386/386boundary