It places a limit N (a timeout value in milliseconds) on how long
a statement is permitted to execute before the server terminates it.

Syntax:
SELECT /*+ MAX_EXECUTION_TIME(milliseconds) */ ...

Only top-level SELECT statements support the hint.

BNL() hint effectively increases join_cache_level up to 4 if it is
set to value less than 4.
This commit also makes the BKA() hint override not only
`join_cache_bka` optimizer switch but `join_cache_level` as well.
I.e., BKA() hint enables BKA and BKAH join buffers both flat and
incremental despite `join_cache_level` and `join_cache_bka` setting.

- Comments in simple_parser.h
- Rename Optimizer_hint_parser::PARSER to Parser (it's not a template
  argument, don't use caps)

This required changing some other functions to const too.

join_cache_level=0 disables join cache buffers, but the hint
BNL() now allows to employ BNL(H) buffers for particular tables
or query blocks.

This commit also adds a number of test cases including
OUTER JOINs to make sure hints do not break the rules of
join buffers application

Forbid adding optimizer hints to view definitions.
In the case when optimizer hints are added to the view definition
at a `CREATE (OR REPLACE) VIEW`/`ALTER VIEW` statement, a warning is
generated and the hints are ignored.

This commit also disables ps-protocol for test cases where
`Unresolved table/index name` warnings are generated. The reason
for this is such warnings are generated during both PREPARE
and EXECUTE stages. Since opt_hints.test has `--enable_prepare_warnings`,
running it with `--ps-protocol` causes duplication of warning messages

- Using Lex_ident_sys to scan identifiers, like the SQL parser does.

  This fixes handling of double-quote-delimited and backtick-delimited identifiers,
  as well as handling of non-ASCII identifiers.

  Unescaping and converting from the client character set to the system
  character set is now done using Lex_ident_cli_st and Lex_ident_sys,
  like it's done in the SQL tokenizer/parser.
  Adding helper methods to_ident_cli() and to_ident_sys()
  in Optimizer_hint_parser::Token.

- Fixing the hint parser to report a syntax error when an empty identifiers:
    SELECT /*+ BKA(``) */ * FROM t1;

- Moving a part of the code from opt_hints_parser.h to opt_hints_parser.cc

  Moving these method definitions:
  - Optimizer_hint_tokenizer::find_keyword()
  - Optimizer_hint_tokenizer::get_token()

  to avoid huge pieces of the code in the header file.

- A Lex_ident_cli_st cleanup
  Fixing a few Lex_ident_cli_st methods to return Lex_ident_cli_st &
  instead of void, to use them easier in the caller code.

- Fixing the hint parser to display the correct line number

  Adding a new data type Lex_comment_st
  (a combination of LEX_CSTRING and a line number)
  Using it in sql_yacc.yy

- Getting rid of redundant dependencies on sql_hints_parser.h

  Moving void LEX::resolve_optimizer_hints() from sql_lex.h to sql_lex.cc

  Adding a class Optimizer_hint_parser_output, deriving from
  Optimizer_hint_parser::Hint_list. Fixing the hint parser to
  return a pointer to an allocated instance of Optimizer_hint_parser_output
  rather than an instance of Optimizer_hint_parser::Hint_list.
  This allows to use a forward declaration of Optimizer_hint_parser_output
  in sql_lex.h and thus avoid dependencies on sql_hints_parser.h.

    This commit introduces:
    - the infrastructure for optimizer hints;
    - hints for join buffering: BNL(), NO_BNL(), BKA(), NO_BKA();
    - NO_ICP() hint for disabling index condition pushdown;
    - MRR(), MO_MRR() hint for multi-range reads control;
    - NO_RANGE_OPTIMIZATION() for disabling range optimization;
    - QB_NAME() for assigning names for query blocks.

Implementing a recursive descent parser for optimizer hints.

- Lex_ident_cli* into a new file sql/lex_ident_cli.h
- Lex_ident_sys* into a new file sql/lex_ident_sys.h
- Well_formed_prefix into include/m_ctype.h

This change is needed to the optimizer hint parser coming soon.

MDEV-33856: Alternative Replication Lag Representation via Received/Executed Master Binlog Event Timestamps

This commit adds 3 new status variables to 'show all slaves status':

- Master_last_event_time ; timestamp of the last event read from the
  master by the IO thread.
- Slave_last_event_time ; Master timestamp of the last event committed
  on the slave.
- Master_Slave_time_diff: The difference of the above two timestamps.

All the above variables are NULL until the slave has started and the
slave has read one query event from the master that changes data.

- Added information_schema.slave_status, which allows us to remove:
   - show_master_info(), show_master_info_get_fields(),
     send_show_master_info_data(), show_all_master_info()
   - class Sql_cmd_show_slave_status.
   - Protocol::store(I_List<i_string_pair>* str_list) as it is not
     used anymore.
- Changed old SHOW SLAVE STATUS and SHOW ALL SLAVES STATUS to
  use the SELECT code path, as all other SHOW ... STATUS commands.

Other things:
- Xid_log_time is set to time of commit to allow slave that reads the
  binary log to calculate Master_last_event_time and
  Slave_last_event_time.
  This is needed as there is not 'exec_time' for row events.
- Fixed that Load_log_event calculates exec_time identically to
  Query_event.
- Updated RESET SLAVE to reset Master/Slave_last_event_time
- Updated SQL thread's update on first transaction read-in to
  only update Slave_last_event_time on group events.
- Fixed possible (unlikely) bugs in sql_show.cc ...old_format() functions
  if allocation of 'field' would fail.

Reviewed By:
Brandon Nesterenko <brandon.nesterenko@mariadb.com>
Kristian Nielsen <knielsen@knielsen-hq.org>

Cleanup unnecessary whitespace at the end of lines and end of files
in the unittest/ directory. Note that all code changes are
non-functional.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.

As this is MariaDB then also variable names in
mariadb-server.*inst should correlate when possible
this change variable and directory names

Gain MySQL compatibility by allowing table aliases in a single
table statement.

This now supports the syntax of:

DELETE [delete_opts] FROM tbl_name [[AS] tbl_alias] [PARTITION (partition_name [, partition_name] ...)] ....

The delete.test is from MySQL commit 1a72b69778a9791be44525501960b08856833b8d
/ Change-Id: Iac3a2b5ed993f65b7f91acdfd60013c2344db5c0.

Co-Author: Gleb Shchepa <gleb.shchepa@oracle.com> (for delete.test)

Reviewed by Igor Babaev (igor@mariadb.com)

Result file needed re-recording to account for the
new information_schema columns

With that, it is possible to restore the full "instance" from a backup
made with mariadb-dump --dir

The patch implements executing DDL (tables, views, triggers) using
statements that are stored in .sql file, created by mariadb-dump
--dir .

Care is taken of creating triggers correctly after the data is loaded,
disabling foreign keys and unique key checks etc.

The files are loaded in descending order by datafile size -
to ensure better work distribution when running with --parallel option.

In addition to --dir option, following options are implemented for
partial restore

include-only options:
--database             -  import one or several databases
--table                -  import one or several tables

exclude options:
--ignore-database      -. ignore one or several databases when importing
--ignore-table         -  to ignore one or several tables when importing

All options above are only valid together with --dir option,
and can be specified multiple times.

Use threadpool, instead of one-thread-and-connection-per-table

Fix tpool to not use maintenance timer for fixed pool size.

Trivial batch, using the handler statistics already collected for
the slow query log.

The reason for the changes in test cases was mainly to change to use
select TABLE_SCHEMA ... from information_schema.table_statistics instead
of 'show table_statistics' to avoid future changes to test results
if we add more columns to table_statistics.

There is no need for a character-set-server configuration when utf8mb4
is now the server default.

Also remove the character-set-collations as its no longer required and
the uca1400_ai_ci is now the default for all character sets that support
it. ref: MDEV-25829 / MDEV-34430.

Changing the default server character set from latin1 to utf8mb4.

Rename some threads to workaround this restrictions,
e.g "rpl_parallel_thread"->"rpl_parallel",
"slave_background" -> "slave_bg" etc.

Use SetThreadDescription/pthread_setname_np to give threads a name.

Use SetThreadDescription/pthread_setname_np to give threads a name.

Builders:
- amd64-fedora-38-last-N-failed
- amd64-debian-10-last-N-failed
erroneously execute MTR for these files:

- rpl/include/rpl_extra_col_master.test
- rpl/include.rpl_binlog_max_cache_size.test
- rpl/include.rpl_charset.test

when these files are changed by a commit.
Changing their extension from *.test to *.inc to avoid this.

my_like_range*() can create longer keys than Field::char_length().
This caused warnings during print_range().

Fix:

Suppressing warnings in print_range().

Line numbers had to be removed from the ignorelists in order to be
diffed against since locations of the same findings can differ
across runs. Therefore preprocessing has to be done on the CI findings
so that it can be compared to the ignorelist and new findings can be
outputted. However, since line numbers have to be removed, a situation
occurs where it is difficult to reference the location of findings
in code given the output of the CI job.

To lessen this pain, change the cppcheck template to include
code snippets which make it easier to reference where in the code
the finding is referring to, even in the absence of line numbers.
Ignorelisting works as before since locations of the finding may
change but not the code it is referring to.

Furthermore, due to the innate difficulty in maintaining ignorelists
across branches and triaging new findings, allow failure as to not
have constantly failing pipelines as a result of a new findings that
have not been addressed yet.

Lastly, update SAST ignorelists to match the newly refactored cppcheck
job and the current state of the codebase.

All new code of the whole pull request, including one or several
files that are either new files or modified ones, are contributed
under the BSD-new license. I am contributing on behalf of my
employer Amazon Web Services, Inc.