Renamed select handler control knob.

        Updated test suite.

      Removed unused code.

    Add a knob to disable Select handler.

        syncronize the schema list at MDB FE and CLX BE.

        Add support for RENAME TABLE.

        Fixed a double free bug in discover_table_details.

texts.

Replaced fixed size uchar arrays for buffers with memory allocations.

Fixed MDB crash in discover_table_details with CX unavailable.

Related to MDEV-21769.

Related to MDEV-21769.

After the '.so' one is supposed to use the directory name, like we have
correctly in all old man pages:
  mysql_client_test_embedded.1:.so man1/mysql_client_test.1
  mysql_embedded.1:.so man1/mysql.1
  mysqltest_embedded.1:.so man1/mysqltest.1

This change adds the 'man1/' component so the link has the correct format.
Actually using man links is a deprecated practice and using symlinks
would be better, but that can be fixed in a later commit.

From https://www.debian.org/doc/debian-policy/ch-docs.html#manual-pages:
> If one man page needs to be accessible via several names it is better
> to use a symbolic link than the .so feature

Detected via Lintian errors:
  E: mariadb-server-10.5: bad-so-link-within-manual-page usr/share/man/man1/mariadb-show.1.gz
  E: mariadb-client-10.5: bad-so-link-within-manual-page usr/share/man/man1/mariadb-binlog.1.gz
  E: mariadb-client-10.5: bad-so-link-within-manual-page usr/share/man/man1/mariadb-plugin.1.gz

Related to MDEV-21769.

This fixes errors like:

  $ LC_ALL=en_US.UTF-8 MANROFFSEQ='' MANWIDTH=80 \
    man --warnings -E UTF-8 -l -Tutf8 -Z mysql-test-run.pl.1 > /dev/null

  troff: <standard input>:246: warning [p 2, 6.0i, div '3tbd1,1', 0.3i]: can't break line
  troff: <standard input>:275: warning [p 2, 6.0i, div '3tbd6,1', 0.8i]: can't break line

Related to MDEV-21769.

Related to MDEV-21769.

Added CYCLE ... RESTRICT (nonstandard) clause to recursive CTE.

The following parameters are deprecated:

  innodb-background-scrub-data-uncompressed
  innodb-background-scrub-data-compressed
  innodb-background-scrub-data-interval
  innodb-background-scrub-data-check-interval

Removed scrubbing code completely(btr0scrub.h, btr0scrub.cc)
Removed information_schema.innodb_tablespaces_scrubbing tables
Removed the scrubbing logic from fil_crypt_thread()

When a InnoDB data file page is freed, its contents becomes garbage,
and any storage allocated in the data file is wasted. During flushing,
InnoDB initializes the page with zeros if scrubbing is enabled. If the
tablespace is compressed then InnoDB should punch a hole else ignore the
flushing of the freed page.

buf_page_t:
- Replaced the variable file_page_was_freed, init_on_flush in buf_page_t
with status enum variable.
- Changed all debug assert of file_page_was_freed to DBUG_ASSERT
of buf_page_t::status

Removed buf_page_set_file_page_was_freed(),
buf_page_reset_file_page_was_freed().

buf_page_free(): Newly added function which takes X-lock on the page
before marking the status as FREED. So that InnoDB flush handler can
avoid concurrent flush of the freed page. Also while flushing the page,
InnoDB make sure that redo log which does freeing of the page also written
to the disk. Currently, this function only marks the page as FREED if
it is in buffer pool

buf_flush_freed_page(): Newly added function which initializes zeros
asynchorously if innodb_immediate_scrub_data_uncompressed is enabled.
Punch a hole to the file synchorously if page_compressed is enabled.
Reset the io_fix to NORMAL. Release the block from flush list and
associated mutex before writing zeros or punch a hole to the file.

buf_flush_page(): Removed the unnecessary usage of temporary
variable "flush"

fil_io(): Introduce new parameter called punch_hole. It allows fil_io()
to punch the hole to the file for the given offset.

buf_page_create(): Let the callers assign buf_page_t::status.
Every caller should eventually invoke mtr_t::init().

fsp_page_create(): Remove the unused mtr_t parameter.

In all other callers of buf_page_create() except fsp_page_create(),
before invoking mtr_t::init(), invoke
mtr_t::sx_latch_at_savepoint() or mtr_t::x_latch_at_savepoint().

mtr_t::init(): Initialize buf_page_t::status also for the temporary
tablespace (when redo logging is disabled), to avoid assertion failures.

MDEV-21833 Make slave_run_triggers_for_rbr enforce triggers to run on slave, even when there are triggers on the master

A bit changed patch of Anders Karlsson with examples added.

New parameters "ENFORCE" to slave-run-triggers-for-rbr added.

MDEV-21854 xa commit `xid` one phase for already prepared transaction must always error out

Added state and one-phase option checks to XA "external" commit/rollback
branches. While the XA standard does not prohibit it,
Commit and Rollback of an XA external to the current ongoing transaction
is not allowed; after all the current transaction may rollback
to not being able to revert that decision.

Let ulong_num being converted by strtoul() rather than strtol().

Engine (InnoDB) and XA replication MDEV-742 requires the XID member
be of a constant minimum across supported platform ulong size which
is 4 bytes.

recv_log_recover_10_4(): Add a missing bit pattern negation that
was forgotten when commit f8a9f906
(MDEV-12353) removed the support for crash-upgrading.

btr_cur_upd_rec_in_place(): Invoke page_zip_rec_set_deleted()
for ROW_FORMAT=COMPRESSED pages, so that the change will be
written to the redo log.

This part of crash recovery was broken in
commit 08ba3887 (MDEV-12353).

create_log_file(): Delete all old redo log files where they used to be
deleted, after the crash injection point innodb_log_abort_6,
before commit 9ef2d29f
deprecated and ignored the setting innodb_log_files_in_group.

log_crypt_101_read_checkpoint(), log_crypt_101_read_block():
Declare as ATTRIBUTE_COLD. These are only used when
checking that a MariaDB 10.1 encrypted redo log is clean.

log_block_calc_checksum_format_0(): Define in the only
compilation unit where it is needed. This is only used
when reading the checkpoint information from redo logs
before MariaDB 10.2.2.

crypt_info_t: Declare the byte arrays directly with alignas().

log_crypt(): Use memcpy_aligned instead of reinterpret_cast
on integers.

Also, correctly document what recv_sys.mutex is protecting.

It is like show_create_table() but allows the caller to specify the
database_name and table_name which are to be printed.

- Don't try to push down SELECTs that have a side effect

- In case the storage engine did support pushdown of SELECT with an INTO
  clause, write the rows we've got from it into select->join->result,
  and not thd->protocol.  This way, SELECT ... INTO ... FROM
  smart_engine_table will put the result into where instructed, and
  NOT send it to the client.

recv_log_recover_pre_10_2(): Merged from
recv_find_max_checkpoint_0(), recv_log_format_0_recover().

Some fields were protected by log_sys.mutex, which adds quite some
overhead for readers. Some readers were submitting dirty reads.

log_t::lsn: Declare private and atomic. Add wrappers get_lsn()
and set_lsn() that will use relaxed memory access. Many accesses
to log_sys.lsn are still protected by log_sys.mutex; we avoid the
mutex for some readers.

log_t::flushed_to_disk_lsn: Declare private and atomic, and move
to the same cache line with log_t::lsn.

log_t::buf_free: Declare as size_t, and move to the same cache line
with log_t::lsn.

log_t::check_flush_or_checkpoint_: Declare private and atomic,
and move to the same cache line with log_t::lsn.

log_get_lsn(): Define as an alias of log_sys.get_lsn().

log_get_lsn_nowait(), log_peek_lsn(): Remove.

log_get_flush_lsn(): Define as an alias of log_sys.get_flush_lsn().

log_t::initiate_write(): Replaces log_buffer_sync_in_background().