The "is it my own thread" check compared the login user name
(Security_context::user) and ignored the host, so u1@localhost could see
and kill threads of u1@'127.0.0.1'.
Compare the authenticated account instead:
* all comparisons are done in sctx->is_priv_user() now
* change user_matches() to priv_user_matches(), which uses is_priv_user()
* use it in KILL, KILL USER, SHOW PROCESSLIST, I_S.PROCESSLIST,
COM_PROCESS_INFO and SHOW EXPLAIN/ANALYZE FOR.
* all the remaining places use is_priv_user() directly instead
of doing strcmp: SHOW GRANTS, SHOW CREATE PROCEDURE, I_S.VIEWS,
the DEFINER clause, optimizer trace and change_security_context().
Assisted-by: Claude:claude-5-opus
user_var_entry objects and their names have a connection lifetime,
they exist until the connection ends (or is reset), and then they're
all deleted at once. This is exactly the use case for MEM_ROOT,
let's store them there.
Additionally, let's set MY_ROOT_USE_VMEM flag to keep this memroot
off the general heap where user_var_entry values are stored
and where heap buffer overflows can happen.
The latter makes memory allocations for the MEM_ROOT about 10x more
expensive, so let's always start with an empty memroot (= zero overhead
if no user variables are used) and on THD cleanup let's retain one
memroot block (= zero overhead if the next connection takes THD from the
cache and uses user variables up to one block size).
Assisted-By: Claude:claude-4.8-opus
On THD::reset, typecast the result of query_start_sec_part() to
tv_usec in a more portable way. Previously, we assumed that the
left hand side was always long-compatible but that isn't the case
on mac.
GROUP_CONCAT is limited by group_concat_max_len,
but also, as a string function it must respect max_allowed_packet.
Let's introduce THD::gconcat_max_len() helper to simplify checks.
Also:
* make max group_concat_max_len value the same as max max_allowed_packet
* use the same MY_MIN((ulonglong) ..., UINT_MAX32) in
Item_func_json_objectagg as in Item_func_group_concat
* use overflow-safe type for lengths in Item_func_quote
(MAX_MAX_ALLOWED_PACKET is 1G so uint cannot overflow yet, but it's
a fragile assumption)
The json_engine killed_ptr was of type uchar however the enum
in the server is dependant on the architecture. On big-endian
architectures like IBM Z, retreiving a uchar* retreived the
unmodifed part of the THD->kill enum location and was always 0.
As C++11 allows enums to inherit a type, used uint32_t as the base
class of killed_state type in the server and used uint32_t in the
json library.
reload_acl_and_cache required an expression change to avoid
the compile error:
sql/sql_reload.cc:472:24: error: enumerated and non-enumerated
type in conditional expression [-Werror=enum-conversion]
472 | return result || (thd ? thd->killed : 0);
Added the kill_ptr assignment the following functions can be
killed:
* Item_func_json_depth::val_int
* Item_func_json_type::val_str
* Item_func_json_length::val_int
Item_func_json_array_append::val_str, check_killed() only applied
to json_error: label and not return_null.
Item_func_json_overlaps::val_bool ensure check_killed() is called.
Item_func_json_format::val_str(), corresponding to the SQL,
json_compact, json_detailed, json_loose - add debug instrumentation
for the func_json_notembedded test.
MDEV-26726 (fcd345de48) added a json_pause_execution sync point
however the test case used debug_max_statement_time, which doesn't
exist. Fix the sync point name in the test.
Routine name resolution performed on a temporary memory root
during execution. So on the second execution LEX::spname members
pointed to a cleared memory.
Fixing to peform the resolution to parse time, like the CALL statement does.
During the execution time LEX::spname members now stay untouched.
When executing an atomic sequence of RENAME operations, such as:
RENAME TABLE t1 TO t2, t3 TO t4, ...
any failure in the sequence triggers a rollback of previously completed
renames to preserve atomicity.
However, when an error occurs, `my_error()` is invoked immediately, which
sets the `thd->is_error()` flag. This premature flag setting causes
the rollback logic to misinterpret the thread state, leading to incorrect
reversion behavior and assertion failures.
To address this, the errors are now not emitted immediately but captured
and postponed. A new class `Postponed_error_handler` is introduced for
this purpose. Only after all operations are completed (including
possible DDL reversion), the captured errors are emitted.
Oracle mode has no priority between set-operators but the current
implementation with disable_index_if_needed() can not work with
arbitrary mix of distinct/non-distinct set-operators as the algorithm
is tied to the properly wrapped version of expression. Index can be
disabled only once and cannot be reenabled afterwards.
To adapt Oracle mode for the aforementioned implementation we
prioritize each set operator with parens in the order of
appearance. So the expression:
S1 op1 S2 op2 S3 op3 S4
will be rewritten like this:
(((S1 op1 S2) op2 S3) op3 S4).
The rewritten expression is valid for both Oracle and default mode and
renders the same result. Prioritizing is done with
create_priority_nest() but it was tweaked to work with derived to be
the first operand. Originally create_priority_nest() could wrap only
second operand, like this:
S1 op1 S2 op2 S3 -> S1 op1 (S2 op2 S3).
Now this behaviour is kept by non-NULL attach_to argument. With NULL
attach_to argument it produces this transformation:
S1 op1 S2 -> (S1 op1 S2), but to be strict it will look like this:
SELECT .. FROM (S1 op1 S2).
This expression is treated as the first one in the select list, so
nothing to "attach to".
On importance of not making fake_select_lex after
create_priority_nest() in parsed_select_expr_start(). This will fail
nastily in Protocol::valid_handler() check in store_longlong() for
EXPLAIN. This happens because select_options are inherited from newly
made fake_select_lex but without SELECT_DESCRIBE flag which is meant
to be assigned by mysql_explain_union() but union_needs_tmp_table() is
false (because now top-level unit has no set-operator, it is just
select from derived), so SELECT_DESCRIBE assignment is
skipped. Depending on that flag send_result_set_metadata() is
conditionally executed in JOIN::exec_inner(). And originally it is
done via select_describe() branch for top-level select when there is
no set operator (it is select from derived as explained above), not
via direct send_result_set_metadata().
On IS_OR_WAS_ORACLE. Sql_mode_save_for_frm_handling removes MODE_ORACLE
when view is registered or opened. We cannot return it back as this
conflicts with MDEV-12478 (tested by compat/oracle.func_concat). So we
are temporarily adding WAS_ORACLE flag instead. WAS_MODE_ORACLE is for
testing both WAS_ORACLE and MODE_ORACLE simultaneously.
They were based on the maximum possible key tuple length, which can be
much larger than the real data size.
The return value is used by handler::keyread_time(), which is used
to estimate the cost of range access.
This could cause range access not to be picked, even if it uses
the clustered PK and reads about 8% of the table.
The fix is to add KEY::stat_storage_length (next to KEY::rec_per_key) and
have the storage engine fill it in handler::info(HA_STATUS_CONST).
Currently, only InnoDB fills this based on its internal statistics:
index->stat_index_size and ib_table->stat_n_rows.
Also changed:
- In handler::calculate_costs(), use ha_keyread_clustered_time() when
computing clustered PK read cost, not ha_keyread_time().
The fix is OFF by default and enabled by setting FIX_INDEX_LOOKUP_COST flag
in @@new_mode.
Setting a name for the the THD::security_ctx:user field for wsrep applier threads.
With this, the audit log events related to wsrep applying will be written in the
audit log.
Using user name <wsrep_applier> for wsrep appliers. This is for having identical
look with async replication, which uses: <replication_slave> for audit logging.
Using same approach as async replication to replace the security_ctx user name
with "system user" for processlist output.
Commit has also a mtr test galera.MDEV-35511, to verify wsrep applier audit logging.
The test does not install/uninstall audit log plugin, but loads the audit log plugin
before the test. This is because uninstalling the audit log plugin gives a warning
saying that plugin is busy and uninstall will be delayed until server shutdown.
This anomaly must be because of the applier thread being active audit logger.
Same problem with plugin uninstall happens also with async relication workers.
If plugn would remain installed, the post test sanity check complains of mismatching
state of pre and post test states, and test execution would fail for this.
The NULL-aware index statistics fix is now controlled by the
FIX_INDEX_STATS_FOR_ALL_NULLS flag and disabled by default
for preserving execution plan stability in stable versions.
To enable:
SET @@new_mode = 'FIX_INDEX_STATS_FOR_ALL_NULLS';
Or via command line:
--new-mode=FIX_INDEX_STATS_FOR_ALL_NULLS
Or in configuration file:
[mysqld]
new_mode=FIX_INDEX_STATS_FOR_ALL_NULLS
`all_nulls_key_parts` bitmap is now calculated at set_statistics_for_table()
don't reload stored routines in the middle of the execution
of a routine. we don't want different iterations of a loop
to see diffefent definitions
For this: remember Cversion in THD on the first sp cache lookup,
after that only compare versions with this value not with Cversion.
@@new_mode is a set of flags to control introduced features.
Flags are by default off. Setting a flag in @@new_mode will introduce
a new different server behaviour and/or set of features.
We also introduce a new option 'hidden_values' into some system variable
types to hide options that we do not wish to show as options.
- Don't print hidden values in mysqld --help output.
- Make get_options() use the same logic as check_new_mode_value() does.
- Setting @@new_mode=ALL shouldn't give warnings.
(cherry picked from commit f7387cb13d)
The test failed as the Jira ticket describes because of insufficient
main transaction isolation from an out-of-band dynamic "new" transaction.
Specifically the replicated transaction's temporary tables became
accessible to the "new" transaction.
The fixes ensure the "new" transaction can't reach any piece of
replication transaction execution context, the temporary table list
including.
This is safe as by so far start_new_trans class instances
need not any replication info, as it must've been anticipated by design.
- Removed duplicate words, like "the the" and "to to"
- Removed duplicate lines (one double sort line found in mysql.cc)
- Fixed some typos found while searching for duplicate words.
Command used to find duplicate words:
egrep -rI "\s([a-zA-Z]+)\s+\1\s" | grep -v param
Thanks to Artjoms Rimdjonoks for the command and pointing out the
spelling errors.
Ensure that Annotate_rows is always written direct after GTID information,
before any table_map events.
Before this patch, the following problems existed when mixing
transactional and not transactional tables in the same statement:
- Annotate rows could be written after row events or in the next GTID
event.
- See rpl_row_mixing_engines
- Annotate_rows was not always written to binary log in case of error
with a transactional table (rolled back) but a not transactional
table was updated.
- See sp_trans_log, binlog_row_mix_innodb_myisam
Fixed by writing the Annotate_rows event into the non transactional
cache if there are not transactional tables used. If not, write the
event into the transactional cache.
See also MDEV-30046.
Idempotent write_row works same as REPLACE: if there is a duplicating
record in the table, then it will be deleted and re-inserted, with the
same update optimization.
The code in Rows:log_event::write_row was basically copy-pasted from
write_record.
What's done:
REPLACE operation was unified across replication and sql. It is now
representred as a Write_record class, that holds the whole state, and allows
re-using some resources in between the row writes.
Replace, IODKU and single insert implementations are split across different
methods, reluting in a much cleaner code.
The entry point is preserved as a single Write_record::write_record() call.
The implementation to call is chosen on the constructor stage.
This allowed several optimizations to be done:
1. The table key list is not iterated for every row. We find last unique key in
the order of checking once and preserve it across the rows. See last_uniq_key().
2. ib_handler::referenced_by_foreign_key acquires a global lock. This call was
done per row as well. Not all the table config that allows optimized replace is
folded into a single boolean field can_optimize. All the fields to check are
even stored in a single register on a 64-bit platform.
3. DUP_REPLACE and DUP_UPDATE cases now have one less level of indirection
4. modified_non_trans_tables is checked and set only when it's really needed.
5. Obsolete bitmap manipulations are removed.
Also:
* Unify replace initialization step across implementations:
add prepare_for_replace and finalize_replace
* alloca is removed in favor of mem_root allocation. This memory is reused
across the rows.
* An rpl-related callback is added to the replace branch, meaning that an extra
check is made per row replace even for the common case. It can be avoided with
templates if considered a problem.
MDEV-6247 added PROCESSLIST states for when a Replication
SQL thread processes Row events, including a WSRep variant
that dynamically includes the Galera Sequence Number.
MDEV-7409 further expanded on it by adding the table name to the states.
However, PROCESSLIST __cannot__ support generated states.
Because it loads the state texts asynchronously,
only permanently static strings are safe.
Even thread-local memory can become invalid when the thread terminates,
which can happen in the middle of generating a PROCESSLIST.
To prioritize memory safety, this commit reverts both variants to
static strings as the non-WSRep variant was before MDEV-7409.
* __Fully__ revert MDEV-7409 (d9898c9a71)
* Remove the WSRep override from MDEV-6247
* Remove `THD::wsrep_info` and its compiler
flag `WSREP_PROC_INFO` as they are now unused
This commit also includes small optimizations
from MDEV-36839’s previous draft, #4133.
Reviewed-by: Brandon Nesterenko <brandon.nesterenko@mariadb.com>
Anonymous block is represented internally by the class sp_head,
so every statement inside an anonymous block is a SP instruction.
On the other hand, the anonymous block specified in the FROM clause of
the PREPARE statement is treated as a single statement. In result,
all parameter markers (represented by the character ?) are parts of
the anonymous block specified in the prepared statement and at the same
time parameter are markers, internally represented by instances of
the class Item_param and distributed among SP instructions representing
SQL statements (every SQL statement is represented by an instance of
the class sp_instr_stmt)
In case table metadata changed on running an anonymous block in prepared
statement mode, only SP instruction's statement is re-parsed. Before
re-parsing a SP's statement, all items are cleaned up including
instances of the class Item_param that represent positional parameters.
Unfortunately, this leads to presence of a dangling pointer in
Prepared_statement::param_array that references to the deleted
Item_param while invoking reset_stmt_params happening on every execution
of a prepared statement.
To fix the issue, no instances of Item_param created on re-parsings
a statement for failed SP instruction, rather instances of Item_param
left from first time parsing are re-used. As a consequence, all pointers
to instances of the class Item_param stored in the array
Prepared_statememt::param_array and possibly spread along the code base
(e.g. select_lex->limit_params.select_limit)
still point to valid Items.
Assertion fails because table is opened by admin_recreate_table():
71 result_code= (thd->open_temporary_tables(table_list) ||
72 mysql_recreate_table(thd, table_list, recreate_info, false));
And that is called because t2 is failed with HA_ADMIN_NOT_IMPLEMENTED:
1093 if (result_code == HA_ADMIN_NOT_IMPLEMENTED && need_repair_or_alter)
1094 {
1095 /*
1096 repair was not implemented and we need to upgrade the table
1097 to a new version so we recreate the table with ALTER TABLE
1098 */
1099 result_code= admin_recreate_table(thd, table, &recreate_info);
1100 }
Actually 'table' is t2 but open_temporary_tables() opens whole list,
i.e. t2 and everything what follows it before first_not_own_table().
Therefore t3 is also opened for t2 processing what is wrong.
The fix opens exactly one specific table for HA_ADMIN_NOT_IMPLEMENTED.
Problem:
Empty queries are incremented if no rows are sent to the client in the
EXECUTE phase of select query. With cursor protocol, rows are not sent
during EXECUTE phase; they are sent later in FETCH phase. Hence,
queries executed with cursor protocol are always falsely treated as
empty in EXECUTE phase.
Fix:
For cursor protocol, empty queries are now counted during the FETCH
phase. This ensures counter correctly reflects whether any rows were
actually sent to the client.
Tests included in `mysql-test/main/show.test`.
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().
This is needed to make it easy for users to automatically ignore long
char and varchars when using ANALYZE TABLE PERSISTENT.
These fields can cause problems as they will consume
'CHARACTERS * MAX_CHARACTER_LENGTH * 2 * number_of_rows' space on disk
during analyze, which can easily be much bigger than the analyzed table.
This commit adds a new user variable, analyze_max_length, default value 4G.
Any field that is bigger than this in bytes, will be ignored by
ANALYZE TABLE PERSISTENT unless it is specified in FOR COLUMNS().
While doing this patch, I noticed that we do not skip GEOMETRY columns from
ANALYZE TABLE, like we do with BLOB. This should be fixed when merging
to the 'main' branch. At the same time we should add a resonable default
value for analyze_max_length, probably 1024, like we have for
max_sort_length.
wait_for_prior_commit() can be called multiple times per event group,
only do my_error() the first time the call fails.
Remove redundant set_overwrite_status() calls.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Reviewed-by: Monty <monty@mariadb.org>
It was not possible to use a package body variable as a
fetch target:
CREATE PACKAGE BODY pkg AS
vc INT := 0;
FUNCTION f1 RETURN INT AS
CURSOR cur IS SELECT 1 AS c FROM DUAL;
BEGIN
OPEN cur;
FETCH cur INTO vc; -- this returned "Undeclared variable: vc" error.
CLOSE cur;
RETURN vc;
END;
END;
FETCH assumed that all fetch targets reside of the same sp_rcontext
instance with the cursor. This patch fixes the problem.
Now a cursor and its fetch target can reside in different sp_rcontext
instances.
Details:
- Adding a helper class sp_rcontext_addr
(a combination of Sp_rcontext_handler pointer and an offset in the rcontext)
- Adding a new class sp_fetch_target deriving from sp_rcontext_addr.
Fetch targets in "FETCH cur INTO target1, target2 ..." are now collected
into this structure instead of sp_variable.
sp_variable cannot be used any more to store fetch targets,
because it does not have a pointer to Sp_rcontext_handler
(it only has the current rcontext offset).
- Removing members sp_instr_set members m_rcontext_handler and m_offset.
Deriving sp_instr_set from sp_rcontext_addr instead.
- Renaming sp_instr_cfetch member "List<sp_variable> m_varlist"
to "List<sp_fetch_target> m_fetch_target_list".
- Fixing LEX::sp_add_cfetch() to return the pointer to the
created sp_fetch_target instance (instead of returning bool).
This helps to make the grammar in sql_yacc.c simpler
- Renaming LEX::sp_add_cfetch() to LEX::sp_add_instr_cfetch(),
as `if(sp_add_cfetch())` changed its meaning to the opposite,
to avoid automatic wrong merge from earlier versions.
- Chaning the "List<sp_variable> *vars" parameter to sp_cursor::fetch
to have the data type "List<sp_fetch_target> *".
- Changing the data type of "List<sp_variable> &vars" in
sp_cursor::Select_fetch_into_spvars::send_data_to_variable_list()
to "List<sp_fetch_target> &".
- Adding THD helper methods get_rcontext() and get_variable().
- Moving the code from sql_yacc.yy into a new LEX method
LEX::make_fetch_target().
- Simplifying the grammar in sql_yacc.yy using the new LEX method.
Changing the data type of the bison rule sp_fetch_list from "void"
to "List<sp_fetch_target> *".
