Ensure that when updating the catalog_xmin of the synced slots, it is first written to disk before changing the in-memory value (effective_catalog_xmin). This is to prevent a scenario where the in-memory value change triggers a vacuum to remove catalog tuples before the catalog_xmin is written to disk. In the event of a crash before the catalog_xmin is persisted, we would not know that some required catalog tuples have been removed and the synced slot would be invalidated. Change the sanity check to ensure that remote_slot's confirmed_flush LSN can't precede the local/synced slot during slot sync. Note that the restart_lsn of the synced/local slot can be ahead of remote_slot. This can happen when slot advancing machinery finds a running xacts record after reaching the consistent state at a later point than the primary where it serializes the snapshot and updates the restart_lsn. Make the check to sync slots robust by allowing to sync only when the confirmed_lsn, restart_lsn, or catalog_xmin of the remote slot is ahead of the synced/local slot. Reported-by: Amit Kapila and Shveta Malik Author: Hou Zhijie, Shveta Malik Reviewed-by: Amit Kapila, Bertrand Drouvot Discussion: https://postgr.es/m/OS0PR01MB57162B67D3CB01B2756FBA6D94062@OS0PR01MB5716.jpnprd01.prod.outlook.com Discussion: https://postgr.es/m/CAJpy0uCSS5zmdyUXhvw41HSdTbRqX1hbYqkOfHNj7qQ+2zn0AQ@mail.gmail.com
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
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