Basic variant of the fix: do not consider conditions in form
unique_key NOT IN (c1,c2...)
to be sargable. If there are only a few constants, the condition
is not selective. If there are a lot constants, the overhead of
processing such a huge range list is not worth it.
A heuristic in best_access_path says that if for an index
ref access involved key parts which are greater than equal to that
for range access, then range access should not be considered.
The assumption made by this heuristic does not hold when
the range optimizer opted to use the group-by min-max optimization.
So the fix here would be to not consider the heuristic if
the range optimizer picked the usage of group-by min-max
optimization.
When the query using a recursive CTE whose definition contained wildcard
symbols in the recursive part was processed at the prepare stage an
assertion was hit if the query was executed without any default database
set. The failure happened when the function insert_fields() tried to check
column privileges for the temporary table created for a recursive
reference to the CTE. No acl checks are needed for any CTE. That's why this
check should be blocked as well. The patch formulates a stricter condition
at which this check is to be blocked that covers the case when a query
using recursive CTEs is executed with no default database set.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
..causes error on slave.
Cause: if the master doesn't have the frm file for the table,
DROP TABLE code will call ha_delete_table_force() to drop the table
in all available storage engines.
The issue was that this code path didn't check for
HTON_TABLE_MAY_NOT_EXIST_ON_SLAVE flag for the storage engine,
and so did not add "... IF EXISTS" to the statement that's written
to the binary log. This can cause error on the slave when it tries to
drop a table that's already gone.
For table references to CTEs the field TABLE_LIST::db must be set to
an empty string as it's done for table references to derived tables in
order CTEs to be processed similar to how derived tables are processed.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
This was noticed wben running "mtr --valgrind main.precedence"
The problem was that Item_func_like::escape could be left unitialized
when used with views combined with UNIONS like in:
create or replace view v1 as select 2 LIKE 1 ESCAPE 3 IN (SELECT 0 UNION SELECT 1), 2 LIKE 1 ESCAPE (3 IN (SELECT 0 UNION SELECT 1)), (2 LIKE 1 ESCAPE 3) IN (SELECT 0 UNION SELECT 1);
The above query causes in fix_escape_item()
escape_item->const_during_execution() to be true
and
escape_item->const_item() to be false
in which case 'escape' is never calculated.
The fix is to make the main logic of fix_escape_item() out to a
separate function and call that function once in Item.
Other things:
- Reorganized fields in Item_func_like class to make it more compact
The reason for the failure is that
thd->mdl_context.release_transactional_locks()
was called after commit & rollback even in cases where the current
transaction is still active.
For 10.2, 10.3 and 10.4 the fix is simple:
- Replace all calls to thd->mdl_context.release_transactional_locks() with
thd->release_transactional_locks(). The thd function will only call
the mdl_context function if there are no active transactional locks.
In 10.6 we will better fix where we will change the return value for
some trans_xxx() functions to indicate if transaction did close the
transaction or not. This will avoid the need of the indirect call.
Other things:
- trans_xa_commit() and trans_xa_rollback() will automatically
call release_transactional_locks() if the transaction is closed.
- We can't do that for the other functions as the caller of many of these
are doing additional work (like close_thread_tables) before calling
release_transactional_locks().
- Added missing abort_result_set() and missing DBUG_RETURN in
select_create::send_eof()
- Fixed wrong indentation in injector::transaction::commit()
The real fix for MDEV-15532 will be pushed into 10.2 and 10.6
This is an additional fix for 10.4.
In 10.4 trans_xa_detach was introduced. However THD::cleanup() assumes
that after trans_xa_detach() is done, there is no registered transactions
anymore. In the 10.2 patch there will be an assert to ensure this, which
will cause 10.4 to fail.
The fix used is to reset the transaction flags in trans_xa_detach().
Allow materialization strategy when collations on the
inner and outer sides of an IN subquery are the same and the
character set of the inner side is a proper subset of the character
set on the outer side.
This allows conversion from utf8mb3 to utf8mb4
as the former is a subset of the later.
This is only allowed when IN predicate is converted to an IN subquery
Backported part of the patch (d6a00d9b18) of MDEV-17905.
When executing set operations in a pipeline using only one temporary table
additional scans of intermediate results may be needed. The scans are
performed with usage of the rnd_next() handler function that might
leave record buffers used for the temporary table not in a state that
is good for following writes into the table. For example it happens for
aria engine when the last call of rnd_next() encounters only deleted
records. Thus a cleanup of record buffers is needed after each such scan
of the temporary table.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
This is for Oracle compatiblity. ENABLED is in Oracle the default case
and just ensures that the NOT NULL constraints will be tested, which is
also default in MariaDB
disable thd->count_cuted_fields when populating internal temporary
tables for I_S, because this is how SELECT works standalone.
And if the SELECT is a part of INSERT or UPDATE or RETURN or SET or
anything else that enables thd->count_cuted_fields, this counting should
only apply when storing the result of the SELECT in a field or a
variable, not when populating internal temporary tables for I_S.
Prior to this patch, it is possible to access freed memory
(THD::event_scheduler) from tp_post_kill_notification().
With this patch, memory is freed only when THD is no more accessible
from other threads, i.e after it is removed from the thread_list.
Do not resend metadata, if metadata does not change between prepare and
execute of prepared statement, or between executes.
Currently, metadata of *every* prepared statement will be checksummed,
and change is detected once checksum changes.
This is not from ideal, performance-wise. The code for
better/faster detection of unchanged metadata, is already in place, but
currently disabled due to PS bugs, such as MDEV-23913.
The idea of this fix is that it's enough to prevent the
next_auto_inc_val from incrementing if an error, to fix this problem
and also the MDEV-17333.
So this patch basically reverts the existing fix to the MDEV-17333.
A bogus error message was issued when a condition was pushed into a
materialized derived table or view specified as union of selects with
aggregation when the corresponding columns of the selects had different
names. This happened because the expression pushed into having clauses of
the selects was adjusted for the names of the first select of the union.
The easiest solution was to rename the columns of the other selects to be
name compatible with the columns of the first select.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
in TABLE_LIST::is_recursive_with_tables
After the patch for MDEV-23619 the code of st_select_lex::cleanup started
using the list st_select_lex::leaf_tables. This list is built for any
query with FROM clause in the function setup_tables(). If such query is
used in a stored procedure it must be ensured that the list is empty
before each new call of the procedure. Otherwise if the first call of
the procedure is successful while the second call reports an error before
the setup_tables() is invoked then list st_select_lex::leaf_tables would
point to a piece of memory that has been already freed.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
The data member tv_usec of the struct timeval is declared as suseconds_t
on MacOS. Size of suseconds_t is 4 bytes. On the other hand, size of ulong
is 8 bytes on 64-bit MacOS, so attempt to assign a value of wider type
(usec) to a value (tv_usec) of narrower type leads to error.
Add a new privilege "SLAVE MONITOR" which will grant user the permission
to execute "SHOW SLAVE STATUS" and "SHOW RELAYLOG EVENTS" commands.
SHOW SLAVE STATUS requires either SLAVE MONITOR/SUPER
SHOW RELAYLOG EVENTS requires SLAVE MONITOR privilege.
