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.
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.
The check go through the following steps:
1. Run check on the underlying engine. If not ok, then return.
2. Check that there's only one row in the table, and
2.1 warn if more than one row
2.2 return HA_ADMIN_CORRUPT if fewer than one row (i.e. 0 rows)
3. If the sequence is not initialised (e.g. after an ALTER TABLE ...
SEQUENCE=1), initialise the sequence by reading the sequence
metadata from the table. This will also flush the next_free_value,
i.e. set it to the next not cached value (SEQUENCE::reserved_until)
4. Check that the sequence metadata is valid, i.e. nothing out of
order e.g. minvalue < maxvalue etc. If invalid it reports
HA_ERR_SEQUENCE_INVALID_DATA
5. Check that the sequence has not been exhausted. It reports
ER_SEQUENCE_RUN_OUT as a warning if and only if a SELECT NEXTVAL
would do so
Limitations:
1. The check is independent of flags, so the vanilla check is the same
as CHECK ... EXTENDED or CHECK ... FOR UPGRADE etc.
2. When the check discovers invalid metadata from the table,
subsequent SELECT NEXTVAL will carry on (or fail) without this
piece of knowledge, independent of the CHECK. This is to ensure
consistency, i.e. CHECK does not modify behaviour of SELECT, and if
anything it makes more sense that SELECT reports
HA_ERR_SEQUENCE_INVALID_DATA in this case, regardless of prior
CHECK
when a definer for SP/view is wrong - it shold be ER_MALFORMED_DEFINER,
not ER_NO_SUCH_USER
when one uses current_role as a definer or grantee but there's no
current role - it should be ER_INVALID_ROLE not ER_MALFORMED_DEFINER
when a non-existent user is specified - it should be ER_NO_SUCH_USER,
which should say "The user does not exist", not "Definer does not exist"
clarify ER_CANT_CHANGE_TX_CHARACTERISTICS to say what cannot be changed
In environments with load balancers or proxies, the audit plugin logs
only the IP address, making it difficult to differentiate individual client
connections from the same IP.
Add a new 'port' field to the appropriate event objects to capture the
client's TCP port number. Populate the port field with thd->port in the
appropriate functions. The audit plugin receives and logs this port field
along with other connection information, enabling better identification
of individual client connections.
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.
Add tls_version and tls_version_length variables to the audit plugin so
they can be logged. This is useful to help identify suspicious or
malformed connections attempting to use unsupported TLS versions. A log
with this information will allow to detect and block more malicious
connection attempts.
Users with 'server_audit_events' empty will have these two new variables
automatically visible in their logs, but if users don't want them, they
can always configure what fields to include by listing the fields in
'server_audit_events'.
In connection event, The TLS version will be populated in `object` field
in key=value format, and the key-value pair will be omitted when the
value is empty.
To ensure the MTR test result matches in all environments, the TLS
version string is replaced with a general `TLS_VERSION` to avoid the MTR
test failing unexpectedly. It stores the version with query `SHOW STATUS
LIKE 'Ssl_version'` and replace the output with `replace_result` command.
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.
[1]: https://docs.openssl.org/3.2/man3/SSL_get_version/
Nothing is broken by this, but the function
Rows_log_event::write_data_header
slightly over-allocates its buf by 2 bytes. It allocates 10
(ROWS_HEADER_LEN_V2), but only 8 are ever written.
This patch fixes the buf size to match what is written (i.e.
ROWS_HEADER_LEN_V1, or 8 bytes).
Reviewed By:
============
Kristian Nielsen <knielsen@knielsen-hq.org>
As seen with openwrt and some other distros, the
determination of hostname can sometime need alternate
commmands.
This provides a cmake option HOSTNAME for non-windows machines
for the mariadb-install-db and mariadbd-safe scripts
and the support-files init scripts..
Promote the last few SQL-inaccessible replication options (command line
or `mariadb.cnf`) as these GLOBAL read-only system variables:
```
@@master_info_file
@@replicate_same_server_id
@@show_slave_auth_info
```
Side effect: The latter two options changed from no argument
to optional argument. Quote `include/my_getopt.h`:
> It should be noted that for historical reasons variables with the
> combination arg_type=NO_ARG, my_option::var_type=GET_BOOL still
> accepts arguments. This is someone counter intuitive and care should
> be taken if the code is refactored.
Reviewed-by: Brandon Nesterenko <brandon.nesterenko@mariadb.com>
Test multi_source.connects tried would sporadically fail with a result
mismatch resembling the following diff:
@@ -29,6 +29,7 @@
SELECT @time_begin, CURRENT_TIMESTAMP(1)
WHERE TIMESTAMPDIFF(SECOND, @time_begin, CURRENT_TIMESTAMP(1)) < 1;
@time_begin CURRENT_TIMESTAMP(1)
+2025-04-28 17:10:08.3 2025-04-28 17:10:09.2
CREATE TEMPORARY TABLE status_sleep AS SELECT 'named' Connection_name, Connects_Tried Connects_Tried;
SET @@SESSION.default_master_connection= '';
include/wait_for_slave_param.inc [Connects_Tried]
This happened due to the reference variable @time_begin being set
_after_ the slave was started. That is, @time_begin was used as the
anchor point at which the time should start ticking for when
Connects_Tried should be incremented; however, MTR may not actually
be able to set it for some time after the slave had started due to
OS scheduling or heavy server load. The failure can be reproduced by
adding a 0.1s sleep statement in-between the aformentioned statements.
The fix is to set @time_begin before starting the slave so it is at
least always valid to reference as the start of the test case.
pppc64le, aarch64, and s390x have char defined as unsigned so
a < 0 comparison is a compile error. The CHAR_MIN defined in limits.h
is 0 on these platforms, false, meaning the if condition is only on
signed char platforms.
To make the interface cleaner we return true on out == 255 to simplify
the calling function.
Valgrind is single threaded and only changes threads as part of
system calls or waits.
Some busy loops were identified and fixed where the server assumes
that some other thread will change the state, which will not happen
with valgrind.
Based on patch by Monty. Original patch introduced VALGRIND_YIELD,
which emits pthread_yield() only in valgrind builds. However it was
agreed that it is a good idea to emit yield() unconditionally, such
that other affected schedulers (like SCHED_FIFO) benefit from this
change. Also avoid pthread_yield() in favour of standard
std::this_thread::yield().
In spatial_utility_function_collect, temporarily exclude the two affected
queries because the DISTINCT flag isn't consistently passed to the
Item_func_collect class. Created MDEV-36695 to address that bug.
In spatial_utility_function_isvalid, add an alias for queries to allow the
test to pass under view protocol.
The minimum statistics level now is rocksdb::StatsLevel::kDisableAll.
The default remains rocksdb::StatsLevel::kExceptHistogramOrTimers
which is now 1 (it used to be 0).
- Added option $backup_on_restart to store a backup of the var/
directory after restart. This is useful for debugging recovery.
- The list_files option in mysqltest is now returning the number of
found files in $sys_files. This is useful to break test if there are
unknown or lost files in the data directory.
