The patch b96c196f1c added a new call for
safe_charset_converter() without a corresponding fix_fields().
In case of a sub-query the created Item remained in non-fixed state.
The problem did not show up with literal derived expressions, only
subselects were affected. This patch adds a corresponding fix_fields()
to the previously added safe_charset_converter().
The select mentioned in the bug attempted to create a temporary table
using the maria storage engine. The table needs to have primary keys such that
duplicates can be removed. Unfortunately this use case has a longer
than allowed key and the tmp table got created without a temporary key.
We must not allow materialization for the subquery if the total key
length and key parts is greater than what the storage engine supports.
Problem was in rewriting left expression which had 2 references on it. Solved with making subselect reference main.
Item_in_optimized can have not Item_in_subselect reference in left part so type casting with no check is dangerous.
Item::cols() should be checked after Item::fix_fields().
Analysis :
==========
During JOIN::prepare of sub-query which creates the
derived tables we call setup_procedure. Here we call
fix_fields for parameters of procedure clause. Calling
setup_procedure at this point may cause issue. If
sub-query is one of parameter being fixed it might
lead to complicated dependencies on derived tables
being prepared.
SOLUTION :
==========
In 5.6 with WL#6242, we have made procedure clause
parameters can only be NUM, so sub-queries are not
allowed as parameters. So in 5.5 we can block
sub-queries in procedure clause parameters.
This eliminates above conflicting dependencies.
- Make JOIN::const_key_parts include keyparts for which
the WHERE clause has an equality in form
"t.key_part=reference_outside_this_select"
- This allows to avoid filesort'ing in some cases (and also
avoid a difficult choice between using filesort or using an index)
update_used_tables for the the where condition to update cached
indicators of constant subexpressions. It should be done before further
possible simplification of the where condition.
This change caused simplification of the executed where conditions
in many test cases.
- MDEV-5587 Server crashes in Locked_tables_list::restore_lock on CREATE OR REPLACE .. SELECT under LOCK
- MDEV-5586 Assertion `share->tdc.all_tables.is_empty() || remove_type != TDC_RT_REMOVE_ALL' fails in tdc_remove_table
- MDEV-5588 Strange error on CREATE OR REPLACE table over an existing view
mysql-test/r/create_or_replace.result:
Added test cases
mysql-test/r/lowercase_view.result:
New error message
mysql-test/r/merge.result:
New error message
mysql-test/r/multi_update.result:
New error message
mysql-test/r/subselect.result:
New error message
mysql-test/r/subselect_exists_to_in.result:
New error message
mysql-test/r/subselect_no_mat.result:
New error message
mysql-test/r/subselect_no_opts.result:
New error message
mysql-test/r/subselect_no_scache.result:
New error message
mysql-test/r/subselect_no_semijoin.result:
New error message
mysql-test/r/view.result:
New error message
mysql-test/suite/funcs_1/r/myisam_views-big.result:
New error message
mysql-test/t/create_or_replace.test:
New tests
mysql-test/t/view.test:
New error message
sql/share/errmsg-utf8.txt:
Added new error message
sql/sql_base.cc:
Updated error message
Do an automatic UNLOCK TABLES if we don't have any locked tables (safety fix)
sql/sql_db.cc:
Updated arguments
sql/sql_load.cc:
New error message
sql/sql_parse.cc:
Check that we are not using a table we are dropping and re-creating
sql/sql_table.cc:
Added parameter to mysql_rm_table_no_locks() to not automaticly do UNLOCK TABLES
Added better error message if trying to drop a view with DROP TABLE
Don't try to create something we select from
sql/sql_table.h:
Updated prototypes
Analysis:
st_select_lex_unit::prepare() computes can_skip_order_by as TRUE.
As a result join->prepare() gets called with order == NULL, and
doesn't do name resolution for the inner ORDER clause. Due to this
the prepare phase doesn't detect that the query references non-exiting
function and field.
Later join->optimize() calls update_used_tables() for a non-resolved
Item_field, which understandably has no Field object. This call results
in a crash.
Solution:
Resolve unnecessary ORDER BY clauses to detect if they reference non-exising
objects. Then remove such clauses from the JOIN object.
The patch to fix mdev-4418 turned out to be incorrect.
At the substitution of single row tables in make_join_statistics()
the used multiple equalities may change and references to the new multiple
equalities must be updated. The function remove_eq_conds() takes care of it and
it should be called right after the substitution of single row tables.
Calling it after the call of make_join_statistics was a mistake.
After single row substitutions there might appear new equalities.
They should be properly propagated to all AND/OR levels the WHERE
condition. It's done now with an additional call of remove_eq_conds().
includes:
* remove some remnants of "Bug#14521864: MYSQL 5.1 TO 5.5 BUGS PARTITIONING"
* introduce LOCK_share, now LOCK_ha_data is strictly for engines
* rea_create_table() always creates .par file (even in "frm-only" mode)
* fix a 5.6 bug, temp file leak on dummy ALTER TABLE
