73a076b03f
The logic for determining how many nbtree pages in an index are deleted pages sometimes undercounted pages. Pages that were deleted by the current VACUUM operation (as opposed to some previous VACUUM operation whose deleted pages have yet to be reused) were sometimes overlooked. The final count is exposed to users through VACUUM VERBOSE's "%u index pages have been deleted" output. btvacuumpage() avoided double-counting when _bt_pagedel() deleted more than one page by assuming that only one page was deleted, and that the additional deleted pages would get picked up during a future call to btvacuumpage() by the same VACUUM operation. _bt_pagedel() can legitimately delete pages that the btvacuumscan() scan will not visit again, though, so that assumption was slightly faulty. Fix the accounting by teaching _bt_pagedel() about its caller's requirements. It now only reports on pages that it knows btvacuumscan() won't visit again (including the current btvacuumpage() page), so everything works out in the end. This bug has been around forever. Only backpatch to v11, though, to keep _bt_pagedel() is sync on the branches that have today's bugfix commit b0229f26da. Note that this commit changes the signature of _bt_pagedel(), just like commit b0229f26da. Author: Peter Geoghegan Reviewed-By: Masahiko Sawada Discussion: https://postgr.es/m/CAH2-WzkrXBcMQWAYUJMFTTvzx_r4q=pYSjDe07JnUXhe+OZnJA@mail.gmail.com Backpatch: 11-
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. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.