Get rid of need of matherialization for usual INSERT (cache results in
Item_cache* if needed)
- subqueries in VALUE do not see new records in the table we are
inserting to
- subqueries in RETIRNING prohibited to use the table we are inserting to
This patch adds support for SYS_REFCURSOR (a weakly typed cursor)
for both sql_mode=ORACLE and sql_mode=DEFAULT.
Works as a regular stored routine variable, parameter and return value:
- can be passed as an IN parameter to stored functions and procedures
- can be passed as an INOUT and OUT parameter to stored procedures
- can be returned from a stored function
Note, strongly typed REF CURSOR will be added separately.
Note, to maintain dependencies easier, some parts of sql_class.h
and item.h were moved to new header files:
- select_results.h:
class select_result_sink
class select_result
class select_result_interceptor
- sp_cursor.h:
class sp_cursor_statistics
class sp_cursor
- sp_rcontext_handler.h
class Sp_rcontext_handler and its descendants
The implementation consists of the following parts:
- A new class sp_cursor_array deriving from Dynamic_array
- A new class Statement_rcontext which contains data shared
between sub-statements of a compound statement.
It has a member m_statement_cursors of the sp_cursor_array data type,
as well as open cursor counter. THD inherits from Statement_rcontext.
- A new data type handler Type_handler_sys_refcursor in plugins/type_cursor/
It is designed to store uint16 references -
positions of the cursor in THD::m_statement_cursors.
- Type_handler_sys_refcursor suppresses some derived numeric features.
When a SYS_REFCURSOR variable is used as an integer an error is raised.
- A new abstract class sp_instr_fetch_cursor. It's needed to share
the common code between "OPEN cur" (for static cursors) and
"OPER cur FOR stmt" (for SYS_REFCURSORs).
- New sp_instr classes:
* sp_instr_copen_by_ref - OPEN sys_ref_curor FOR stmt;
* sp_instr_cfetch_by_ref - FETCH sys_ref_cursor INTO targets;
* sp_instr_cclose_by_ref - CLOSE sys_ref_cursor;
* sp_instr_destruct_variable - to destruct SYS_REFCURSOR variables when
the execution goes out of the BEGIN..END block
where SYS_REFCURSOR variables are declared.
- New methods in LEX:
* sp_open_cursor_for_stmt - handles "OPEN sys_ref_cursor FOR stmt".
* sp_add_instr_fetch_cursor - "FETCH cur INTO targets" for both
static cursors and SYS_REFCURSORs.
* sp_close - handles "CLOSE cur" both for static cursors and SYS_REFCURSORs.
- Changes in cursor functions to handle both static cursors and SYS_REFCURSORs:
* Item_func_cursor_isopen
* Item_func_cursor_found
* Item_func_cursor_notfound
* Item_func_cursor_rowcount
- A new system variable @@max_open_cursors - to limit the number
of cursors (static and SYS_REFCURSORs) opened at the same time.
Its allowed range is [0-65536], with 50 by default.
- A new virtual method Type_handler::can_return_bool() telling
if calling item->val_bool() is allowed for Items of this data type,
or if otherwise the "Illegal parameter for operation" error should be raised
at fix_fields() time.
- New methods in Sp_rcontext_handler:
* get_cursor()
* get_cursor_by_ref()
- A new class Sp_rcontext_handler_statement to handle top level statement
wide cursors which are shared by all substatements.
- A new virtual method expr_event_handler() in classes Item and Field.
It's needed to close (and make available for a new OPEN)
unused THD::m_statement_cursors elements which do not have any references
any more. It can happen in various moments in time, e.g.
* after evaluation parameters of an SQL routine
* after assigning a cursor expression into a SYS_REFCURSOR variable
* when leaving a BEGIN..END block with SYS_REFCURSOR variables
* after setting OUT/INOUT routine actual parameters from formal
parameters.
Protocol_text constructor allocated memory on an optional prealloc argument.
This was along with its subclass Protocol_local.
Remove this functionality to an independent member function "allocate".
Replace two use with existing error handling on insufficient
resources at the err label.
Protocol_local, that inherits from Protocol_text had one use that
requested an allocation of 0. So it wasn't needed.
The fix for MDEV-35318 has introduced LEX::needs_reprepare and logic in
Prepared_statement::execute_loop() and sp_lex_keeper::
validate_lex_and_exec_core() to re-prepare the statement if it has hit
an error when doing once-per-statement-life optimizations.
But there is also third code path: PS with Array Binding is handled in
Prepared_statement::execute_bulk_loop(). Add handling there as well.
Followup to fix for MDEV-35318: In Prepared_statement::execute_loop(),
if we enter this function with lex->needs_reprepare=true, we need to
re-prepare the statement.
We also need to call set_parameters() to get PS parameter values. We
failed to do this and that's the bug.
Note that we need to also handle the other reprepare scenario: when
we get into Prepared_statement::execute_loop(), call set_parameters()
and then hit a "DDL was changed" error with reprepare_observer,
we should NOT call set_parameters() again.
The parameters have already been transferred to the reprepared statement
in Prepared_statement::reprepare()|swap_parameter_array().
* rpl.rpl_system_versioning_partitions updated for MDEV-32188
* innodb.row_size_error_log_warnings_3 changed error for MDEV-33658
(checks are done in a different order)
Alternative, more general fix, Variant 2.
The problem was as follows: Suppose we are running a PS/SP statement and
we get an error while doing optimization that is done once per statement
life. This may leave the statement data structures in an undefined state,
where it is not safe to execute it again.
The fix: introduce LEX::needs_reprepare and set it in such cases.
Make PS and SP runtime check it and re-prepare the statement before
executing it again.
We do not use Reprepare_observer, because it turns out it is tightly tied
to watching versions of statement's objects. For example, it must not be
used when running the statement for the first time, exactly when the
once-per-statement-lifetime optimizations are done.
- Needless engaged_ removed;
- SCOPE_VALUE, SCOPE_SET, SCOPE_CLEAR macros for neater declaration;
- IF_CLASS / IF_NOT_CLASS SFINAE checkers to pass arg by value or
reference;
- inline keyword;
- couple of refactorings of temporary free_list.
The problems were that:
1) resources was freed "asimetric" normal execution in send_eof,
in case of error in destructor.
2) destructor was not called in case of SP for result objects.
(so if the last SP execution ended with error resorces was not
freeded on reinit before execution (cleanup() called before next
execution) and destructor also was not called due to lack of
delete call for the object)
Result cleanup() renamed to reset_for_next_ps_execution() to better
reflect function().
All result method revised and freeing resources made "symetric".
Destructor of result object called for SP.
Added skipped invalidation in case of error in insert.
Removed misleading naming of reset(thd) (could be mixed with
with reset()).
The previous commit for fixing MDEV-35446 disabled setting
Galera errors on COM_STMT_PREPARE commands.
As a side effect, a number of tests were started to fail
due to the client receiving different error codes from the
ones expected in the test dependending on whether --ps-protocol
was used.
Also, in the case of test galera_ftwrl, it was found that
it is expected that during COM_STMT_PREPARE command, we
may perform a sync wait operation, which can fail with
LOCK_WAIT_TIMEOUT error.
The revised fix consists in anticipating the call to
wsrep_after_command_before_result(), so that we check for
BF aborts or errors during statement prepare, before sending
back the statement metadata message to client.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
When binding to NULL, DEFAULT or IGNORE from an Item value, Item_param did not
change m_type_handler, so its value remained from the previous bind.
Thid led to DBUG_ASSERTs in Item_param::get_date() and
Timestamp_or_zero_datetime_native_null.
Fix:
Set Item_param::m_type_handler to &type_handler_null when
binding from an Item returning NULL.
This patch also fixes MDEV-35427.
This task is inspired by the Percona implementation of
slow_query_log_always_write_time.
This task implements the variable log_slow_always_query_time (name
matching other MariaDB variables using the slow query log). The
default value for the variable is 31536000, which makes MariaDB
compatible with older installations.
For queries with execution time longer than log_slow_always_query_time
the variables log_slow_rate_limit and log_slow_min_examined_row_limit
will be ignored and the query will be written to the slow query log
if there is no other limitations (like log_slow_filter etc).
Other things:
- long_query_time internal variable renamed to log_slow_query_time.
- More descriptive information for "log_slow_query_time".
The problem was that when using clang + asan, we do not get a correct value
for the thread stack as some local variables are not allocated at the
normal stack.
It looks like that for example clang 18.1.3, when compiling with
-O2 -fsanitize=addressan it puts local variables and things allocated by
alloca() in other areas than on the stack.
The following code shows the issue
Thread 6 "mariadbd" hit Breakpoint 3, do_handle_one_connection
(connect=0x5080000027b8,
put_in_cache=<optimized out>) at sql/sql_connect.cc:1399
THD *thd;
1399 thd->thread_stack= (char*) &thd;
(gdb) p &thd
(THD **) 0x7fffedee7060
(gdb) p $sp
(void *) 0x7fffef4e7bc0
The address of thd is 24M away from the stack pointer
(gdb) info reg
...
rsp 0x7fffef4e7bc0 0x7fffef4e7bc0
...
r13 0x7fffedee7060 140737185214560
r13 is pointing to the address of the thd. Probably some kind of
"local stack" used by the sanitizer
I have verified this with gdb on a recursive call that calls alloca()
in a loop. In this case all objects was stored in a local heap,
not on the stack.
To solve this issue in a portable way, I have added two functions:
my_get_stack_pointer() returns the address of the current stack pointer.
The code is using asm instructions for intel 32/64 bit, powerpc,
arm 32/64 bit and sparc 32/64 bit.
Supported compilers are gcc, clang and MSVC.
For MSVC 64 bit we are using _AddressOfReturnAddress()
As a fallback for other compilers/arch we use the address of a local
variable.
my_get_stack_bounds() that will return the address of the base stack
and stack size using pthread_attr_getstack() or NtCurrentTed() with
fallback to using the address of a local variable and user provided
stack size.
Server changes are:
- Moving setting of thread_stack to THD::store_globals() using
my_get_stack_bounds().
- Removing setting of thd->thread_stack, except in functions that
allocates a lot on the stack before calling store_globals(). When
using estimates for stack start, we reduce stack_size with
MY_STACK_SAFE_MARGIN (8192) to take into account the stack used
before calling store_globals().
I also added a unittest, stack_allocation-t, to verify the new code.
Reviewed-by: Sergei Golubchik <serg@mariadb.org>
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>
