it's incorrect to use change_item_tree() to replace arguments
of top-level AND/OR, because they (arguments) are stored in a List,
so a pointer to an argument is in the list_node, and individual
list_node's of top-level AND/OR can be deleted in Item_cond::build_equal_items().
In that case rollback_item_tree_changes() will modify the deleted object.
Luckily, it's not needed to use change_item_tree() for top-level
AND/OR, because the whole top-level item is copied and preserved
in prep_where and prep_on, and restored from there.
So, just don't.
If all elements in the list of 'IN' or 'NOT IN' clause are equal
and there are no NULLs then clause
- "a IN (e1,..,en)" can be converted to "a = e1"
- "a NOT IN (e1,..,en)" can be converted to "a <> e1".
This means an object of Item_func_in can be replaced with an object
of Item_func_eq for IN (e1,..,en) clause and Item_func_ne for
NOT IN (e1,...,en). Such a replacement allows the optimizer to choose
a better execution plan
To prevent ASAN heap-use-after-poison in the MDEV-16549 part of
./mtr --repeat=6 main.derived
the initialization of Name_resolution_context was cleaned up.
SELECT FROM JSON_TABLE
Analysis: When fix_fields_if_needed() is called, it doesnt check if operands
are valid because check_cols() is not called. So it doesn't error out and
eventually crashes.
Fix: Use fix_fields_if_needed_for_scalar() instead of
fix_fields_if_needed(). It filters the scalar and returns the error if
it occurs.
Nowdays subquery in a UNION's ORDER BY placed correctly in fake select,
the only problem was incorrect Name_resolution_contect is fixed by this
patch in parsing, so we do not need scanning/reseting of ORDER BY of
a union.
1. Store assignment failures on incompatible data types now raise errors if:
- STRICT_ALL_TABLES or STRICT_TRANS_TABLES sql_mode is used, and
- IGNORE is not used
Otherwise, only a warning is raised and the statement continues.
2. Changing the error/warning test as follows:
-ERROR HY000: Illegal parameter data types inet6 and int for operation 'SET'
+ERROR HY000: Cannot cast 'int' as 'inet6' in assignment of `db`.`t`.`col`
so in case of a big table it's easier to see which column has the problem.
The new error text is also applied to SP variables.
Now INSERT, UPDATE, ALTER statements involving incompatible data type pairs, e.g.:
UPDATE TABLE t1 SET col_inet6=col_int;
INSERT INTO t1 (col_inet6) SELECT col_in FROM t2;
ALTER TABLE t1 MODIFY col_inet6 INT;
consistently return an error at the statement preparation time:
ERROR HY000: Illegal parameter data types inet6 and int for operation 'SET'
and abort the statement before starting interating rows.
This error is the same with what is raised for queries like:
SELECT col_inet6 FROM t1 UNION SELECT col_int FROM t2;
SELECT COALESCE(col_inet6, col_int) FROM t1;
Before this change the error was caught only during the execution time,
when a Field_xxx::store_xxx() was called for the very firts row.
The behavior was not consistent between various statements and could do different things:
- abort the statement
- set a column to the data type default value (e.g. '::' for INET6)
- set a column to NULL
A typical old error was:
ERROR 22007: Incorrect inet6 value: '1' for column `test`.`t1`.`a` at row 1
EXCEPTION:
Note, there is an exception: a multi-row INSERT..VALUES, e.g.:
INSERT INTO t1 (col_a,col_b) VALUES (a1,b1),(a2,b2);
checks assignment compability at the preparation time for the very first row only:
(col_a,col_b) vs (a1,b1)
Other rows are still checked at the execution time and return the old warnings
or errors in case of a failure. This is done because catching all rows at the
preparation time would change behavior significantly. So it still works
according to the STRICT_XXX_TABLES sql_mode flags and the table transaction ability.
This is too late to change this behavior in 10.7.
There is no a firm decision yet if a multi-row INSERT..VALUES
behavior will change in later versions.
Errors where:
/buildbot/amd64-ubuntu-2004-msan/build/sql/item.h:6478:12: error: 'val_datetime_packed' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
longlong val_datetime_packed(THD *thd)
^
/buildbot/amd64-ubuntu-2004-msan/build/sql/item.h:3501:12: note: overridden virtual function is here
longlong val_datetime_packed(THD *thd) override;
^
/buildbot/amd64-ubuntu-2004-msan/build/sql/item.h:6480:12: error: 'val_time_packed' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
longlong val_time_packed(THD *thd)
^
/buildbot/amd64-ubuntu-2004-msan/build/sql/item.h:3502:12: note: overridden virtual function is here
longlong val_time_packed(THD *thd) override;
^
SHOW EXPLAIN/ANALYZE FORMAT=JSON tries to access items that have already been
freed by a call to free_items() during THD::cleanup_after_query().
The solution is to disallow APC calls including SHOW EXPLAIN/ANALYZE
just before the call to free_items().
When doing condition pushdown from HAVING into WHERE,
Item_equal::create_pushable_equalities() calls
item->set_extraction_flag(IMMUTABLE_FL) for constant items.
Then, Item::cleanup_excluding_immutables_processor() checks for this flag
to see if it should call item->cleanup() or leave the item as-is.
The failure happens when a constant item has a non-constant one inside it,
like:
(tbl.col=0 AND impossible_cond)
item->walk(cleanup_excluding_immutables_processor) works in a bottom-up
way so it
1. will call Item_func_eq(tbl.col=0)->cleanup()
2. will not call Item_cond_and->cleanup (as the AND is constant)
This creates an item tree where a fixed Item has an un-fixed Item inside
it which eventually causes an assertion failure.
Fixed by introducing this rule: instead of just calling
item->set_extraction_flag(IMMUTABLE_FL);
we call Item::walk() to set the flag for all sub-items of the item.
because CONTEXT_ANALYSIS_ONLY_VCOL_EXPR can be used only for,
exactly, context analysys. Items fixed that way cannot be evaluated.
But vcols are going to be evaluated, so they have to be fixed properly,
for evaluation.
column generated using date_format() and if()
vcol_info->expr is allocated on expr_arena at parsing stage. Since
expr item is allocated on expr_arena all its containee items must be
allocated on expr_arena too. Otherwise fix_session_expr() will
encounter prematurely freed item.
When table is reopened from cache vcol_info contains stale
expression. We refresh expression via TABLE::vcol_fix_exprs() but
first we must prepare a proper context (Vcol_expr_context) which meets
some requirements:
1. As noted above expr update must be done on expr_arena as there may
be new items created. It was a bug in fix_session_expr_for_read() and
was just not reproduced because of no second refix. Now refix is done
for more cases so it does reproduce. Tests affected: vcol.binlog
2. Also name resolution context must be narrowed to the single table.
Tested by: vcol.update main.default vcol.vcol_syntax gcol.gcol_bugfixes
3. sql_mode must be clean and not fail expr update.
sql_mode such as MODE_NO_BACKSLASH_ESCAPES, MODE_NO_ZERO_IN_DATE, etc
must not affect vcol expression update. If the table was created
successfully any further evaluation must not fail. Tests affected:
main.func_like
Reviewed by: Sergei Golubchik <serg@mariadb.org>
1. moved fix_vcol_exprs() call to open_table()
mysql_alter_table() doesn't do lock_tables() so it cannot win from
fix_vcol_exprs() from there. Tests affected: main.default_session
2. Vanilla cleanups and comments.
