it's incorrect to zero out table->triggers->extra_null_bitmap
before a statement, because if insert uses an explicit field list
and omits a field that has no default value, the field should
get NULL implicitly. So extra_null_bitmap should have 1s for all
fields that have no defaults
* create extra_null_bitmap_init and initialize it as above
* copy extra_null_bitmap_init to extra_null_bitmap for inserts
* still zero out extra_null_bitmap for updates/deletes where
all fields definitely have a value
* make not_null_fields_have_null_values() to send
ER_NO_DEFAULT_FOR_FIELD for fields with no default and no value,
otherwise creation of a trigger with an empty body would change the
error message
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()).
This bug has the same nature as the issues
MDEV-34718: Trigger doesn't work correctly with bulk update
MDEV-24411: Trigger doesn't work correctly with bulk insert
To fix the issue covering all use cases, resetting the thd->bulk_param
temporary to the value nullptr before invoking triggers and restoring
its original value on finishing execution of a trigger is moved to the method
Table_triggers_list::process_triggers
that be invoked ultimately for any kind of triggers.
MDEV-34447 Removed setting first_cond_optimization to 0 in update and
delete when leaf_tables_saved. This can cause problems when two ps
executions of an update go through different paths, where the first ps
execution goes through single table update only and the second ps
execution also goes through multi table update. When this happens, the
first_cond_optimization of the outer query is not set to false during
the first ps execution because optimize() is not called for the outer
query. But then the second ps execution will call optimize() on the
outer query, which with first_cond_optimization==true trips the 2nd ps
mem leak detection.
This is not a problem in higher version as both executions go through
multi table updates, possibly due to MDEV-28883.
We fix this problem by restoring the FALSE assignments to
first_cond_optimization.
The memory leak happened on second execution of a prepared statement
that runs UPDATE statement with correlated subquery in right hand side of
the SET clause. In this case, invocation of the method
table->stat_records()
could return the zero value that results in going into the 'if' branch
that handles impossible where condition. The issue is that this condition
branch missed saving of leaf tables that has to be performed as first
condition optimization activity. Later the PS statement memory root
is marked as read only on finishing first time execution of the prepared
statement. Next time the same statement is executed it hits the assertion
on attempt to allocate a memory on the PS memory root marked as read only.
This memory allocation takes place by the sequence of the following
invocations:
Prepared_statement::execute
mysql_execute_command
Sql_cmd_dml::execute
Sql_cmd_update::execute_inner
Sql_cmd_update::update_single_table
st_select_lex::save_leaf_tables
List<TABLE_LIST>::push_back
To fix the issue, add the flag SELECT_LEX::leaf_tables_saved to control
whether the method SELECT_LEX::save_leaf_tables() has to be called or
it has been already invoked and no more invocation required.
Similar issue could take place on running the DELETE statement with
the LIMIT clause in PS/SP mode. The reason of memory leak is the same as for
UPDATE case and be fixed in the same way.
Running an UPDATE statement in PS mode and having positional
parameter(s) bound with an array of actual values (that is
prepared to be run in bulk mode) results in incorrect behaviour
in presence of on update trigger that also executes an UPDATE
statement. The same is true for handling a DELETE statement in
presence of on delete trigger. Typically, the visible effect of
such incorrect behaviour is expressed in a wrong number of
updated/deleted rows of a target table. Additionally, in case UPDATE
statement, a number of modified rows and a state message returned
by a statement contains wrong information about a number of modified rows.
The reason for incorrect number of updated/deleted rows is that
a data structure used for binding positional argument with its
actual values is stored in THD (this is thd->bulk_param) and reused
on processing every INSERT/UPDATE/DELETE statement. It leads to
consuming actual values bound with top-level UPDATE/DELETE statement
by other DML statements used by triggers' body.
To fix the issue, reset the thd->bulk_param temporary to the value
nullptr before invoking triggers and restore its value on finishing
its execution.
The second part of the problem relating with wrong value of affected
rows reported by Connector/C API is caused by the fact that diagnostics
area is reused by an original DML statement and a statement invoked
by a trigger. This fact should be take into account on finalizing a
state of diagnostics area on completion running of a statement.
Important remark: in case the macros DBUG_OFF is on, call of the method
Diagnostics_area::reset_diagnostics_area()
results in reset of the data members
m_affected_rows, m_statement_warn_count.
Values of these data members of the class Diagnostics_area are used on
sending OK and EOF messages. In case DML statement is executed in PS bulk
mode such resetting results in sending wrong result values to a client
for affected rows in case the DML statement fires a triggers. So, reset
these data members only in case the current statement being processed
is not run in bulk mode.
The memory leak happened on second execution of a prepared statement
that runs UPDATE statement with correlated subquery in right hand side of
the SET clause. In this case, invocation of the method
table->stat_records()
could return the zero value that results in going into the 'if' branch
that handles impossible where condition. The issue is that this condition
branch missed saving of leaf tables that has to be performed as first
condition optimization activity. Later the PS statement memory root
is marked as read only on finishing first time execution of the prepared
statement. Next time the same statement is executed it hits the assertion
on attempt to allocate a memory on the PS memory root marked as read only.
This memory allocation takes place by the sequence of the following
invocations:
Prepared_statement::execute
mysql_execute_command
Sql_cmd_dml::execute
Sql_cmd_update::execute_inner
Sql_cmd_update::update_single_table
st_select_lex::save_leaf_tables
List<TABLE_LIST>::push_back
To fix the issue, add the flag SELECT_LEX::leaf_tables_saved to control
whether the method SELECT_LEX::save_leaf_tables() has to be called or
it has been already invoked and no more invocation required.
Similar issue could take place on running the DELETE statement with
the LIMIT clause in PS/SP mode. The reason of memory leak is the same as for
UPDATE case and be fixed in the same way.
(Based on original patch by Oleksandr Byelkin)
Multi-table DELETE can execute via "buffered" mode: at phase #1 it collects
rowids of rows to be deleted, then at phase #2 in multi_delete::do_deletes()
it calls handler->rnd_pos() to read rows to be deleted and deletes them.
The problem occurred when phase #1 used Rowid Filter on the table that
phase #2 would be deleting from.
In InnoDB, h->rnd_init(scan=false) and h->rnd_pos() is an index scan over PK
under the hood. So, at phase #2 ha_innobase::rnd_init() would try to use the
Rowid Filter and hit an assertion inside ha_innobase::rnd_init().
Note that multi-table UPDATE works similarly but was not affected, because
patch for MDEV-7487 added code to disable rowid filter for phase #2 in
multi_update::do_updates().
This patch changes the approach:
- It makes InnoDB not use Rowid Filter in rnd_pos() scans: it is disabled in
ha_innobase::rnd_init() and enabled back in ha_innobase::rnd_end().
- multi_update::do_updates() no longer disables Rowid Filter for phase#2 as
it is no longer necessary.
Some fixes related to commit f838b2d799 and
Rows_log_event::do_apply_event() and Update_rows_log_event::do_exec_row()
for system-versioned tables were provided by Nikita Malyavin.
This was required by test versioning.rpl,trx_id,row.
This was caused by wrong allocation of variable on stack.
(Was allocating 4K of data instead of 512 bytes).
No test case as the original MDEV test cases is not usable for mtr.
This patch fixes the issue with passing the DEFAULT or IGNORE values to
positional parameters for some kind of SQL statements to be executed
as prepared statements.
The main idea of the patch is to associate an actual value being passed
by the USING clause with the positional parameter represented by
the Item_param class. Such association must be performed on execution of
UPDATE statement in PS/SP mode. Other corner cases that results in
server crash is on handling CREATE TABLE when positional parameter
placed after the DEFAULT clause or CALL statement and passing either
the value DEFAULT or IGNORE as an actual value for the positional parameter.
This case is fixed by checking whether an error is set in diagnostics
area at the function pack_vcols() on return from the function pack_expression()
