When a InnoDB data file page is freed, its contents becomes garbage, and any storage allocated in the data file is wasted.
MariaDB 10.4 introduced an InnoDB redo log record MLOG_INIT_FREE_PAGE for marking pages as freed. In
MDEV-12353 (MariaDB 10.5.2), that record was replaced with FREE_PAGE. This record could be treated as no-op, or we can punch a hole for page_compressed=1 tables.
If innodb_immediate_scrub_data_uncompressed is set, we should initialize the page with zeros. This will replace some of the non-working scrubbing logic (MDEV-8139). The scrubbing will be fixed further in MDEV-8139.
The following parameters will be deprecated and ignored and the problematic ‘background scrubbing’ code removed:
For page_compressed tables the freed page will be hole-punched