Backwards scans that reach a half-dead leftmost leaf page step over the
page without calling _bt_readpage. This happens whenever the most
recent _bt_lock_and_validate_left call returned a half-dead leftmost
page. An assertion within _bt_readnextpage failed to consider this,
causing it to fail spuriously.
To fix, make the assertion accept the case where currPage doesn't match
lastcurrblkno as long as blkno is P_NONE (it's always P_NONE when the
last leaf page examined by _bt_readnextpage is either the leftmost or
rightmost page).
Oversight in commit caca6d8d27.
Author: Peter Geoghegan <pg@bowt.ie>
Backpatch-through: 18
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.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/18/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/18/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.