MDEV-5337: Wrong result in mariadb 5.5.32 with ORDER BY + LIMIT when
index_condition_pushdown=on
- in test_if_skip_sort_order(), correct the condition under which
we have the code that restores the previously pushed index condition.
Main fix was to not cache derivied tables as they may be temporary tables that are deleted before the next query.
This was a bit tricky as Item_field::fix_fields depended on cached_tables to be set to resolve some columns.
mysql-test/r/sp-bugs.result:
Added test case
mysql-test/t/sp-bugs.test:
Added test case
sql/item.cc:
Fixed fix_outer_field to handle case where found field did not have in cached_table
Idea is that if cached_table is not avaliable, use from_field->table->pos_in_table_list instead
sql/records.cc:
Also accept INTERNAL_TMP_TABLE for memmap
sql/sql_base.cc:
More DBUG_PRINT
Fixed that setup_natural_join_row_types() is not run twice.
Original code modified context->first_name_resolution_table also for second executions.
This was wrong as this could give wrong results if some joins had been optimized away between calls.
sql/sql_derived.cc:
Mark derived tables as internal temporary tables (INTERNAL_TMP_TABLE), not as NON_TRANSACTIONAL_TMP_TABLE.
This is more correct as the tables are not visible by the end user.
sql/sql_insert.cc:
Reset pos_in_table_list before calling fix_fields.
One of the consequences of the change of not caching all generated tables in Item_ident is that
pos_in_table_list needs to be correct in calls to fix_fields.
sql/sql_lex.cc:
More DBUG_PRINT
sql/sql_parse.cc:
Don't cache derivied tables as they may be temporary tables that are deleted before the next query
sql/sql_select.cc:
Reset table_vector. This was required as some code checked the vector to see if temporary tables had already been created.
sql/table.cc:
Mark tables with field translations as cacheable (as these will not disapper between stmt executions.
THD::thd->activate_stmt_arena_if_needed() should be used to temporary activating statement arena instead of direct usage of THD::set_n_backup_active_arena() because possible such scenario:
1) func1 saves current arena and activates copy1 of statement arena
2) func2 saves copy1 of statement arena setup by func1 and activates copy2
3) some changes made for copy 2
4) func2 stores changed copy2 back to statenet arena and activates copy1
5) func1 store unchanged copy1 back to statemnt arena (rewrite changed copy 2 so changes become lost) and activates arena which was before.
THD::thd->activate_stmt_arena_if_needed() should be used to temporary activating statement arena instead of direct usage of THD::set_n_backup_active_arena() because possible such scenario:
1) func1 saves current arena and activates copy1 of statement arena
2) func2 saves copy1 of statement arena setup by func1 and activates copy2
3) some changes made for copy 2
4) func2 stores changed copy2 back to statenet arena and activates copy1
5) func1 store unchanged copy1 back to statemnt arena (rewrite changed copy 2 so changes become lost) and activates arena which was before.
- When a JOIN has both "optimization tabs" (JOIN_TABs used to
read the base tables and do the join operation) and also
has "execution tabs" (a JOIN_TAB that is to produce result set
that is sent to the client), do not forget to call JOIN_TAB::cleanup()
for the execution JOIN_TAB.
This only happend when using an ORDER BY on a primary key part, where all other key parts where constant.
Remove of duplicated expressions in ORDER BY (as the old code did this in some strange cases)
mysql-test/r/group_by.result:
Fixed results to take into account that duplicate order by parts are now deleted
mysql-test/r/group_by_innodb.result:
Ensure extended keys are on
mysql-test/r/innodb_ext_key.result:
More tests
mysql-test/r/order_by.result:
More tests
mysql-test/t/group_by.test:
Fixed results to take into account that duplicate order by parts are now deleted
mysql-test/t/group_by_innodb.test:
Ensure extended keys are on
mysql-test/t/innodb_ext_key.test:
More tests
mysql-test/t/order_by.test:
More tests
sql/sql_select.cc:
Fixed bug where we looked at extended key parts when we shouldn't
Remove of duplicated expressions in ORDER BY
sql/table.cc:
Indentation fixes
- Added MALLOC_LIBRARY variable to hold name of malloc library
- Back ported valgrind related fixes from jemalloc 3.4.1 to the included jemalloc 3.3.1
- Renamed bitmap_init() and bitmap_free() to my_bitmap_init() and my_bitmap_free() to avoid clash with jemalloc 3.4.1
- Use option --soname-synonyms=somalloc=NON to valgrind when using jemalloc
- Show version related variables in mysqld --help
-- Added SHOW_VALUE_IN_HELP marker
Increased back_log to 150 as the original value was a bit too small
CMakeLists.txt:
Added MALLOC_LIBRARY variable to hold name of malloc library
cmake/jemalloc.cmake:
Added MALLOC_LIBRARY variable to hold name of malloc library
config.h.cmake:
Added MALLOC_LIBRARY variable to hold name of malloc library
extra/jemalloc/ChangeLog:
Updates changelog
extra/jemalloc/include/jemalloc/internal/arena.h:
Backported valgrind fixes from jemalloc 3.4.1
extra/jemalloc/include/jemalloc/internal/jemalloc_internal.h.in:
Backported valgrind fixes from jemalloc 3.4.1
extra/jemalloc/include/jemalloc/internal/private_namespace.h:
Backported valgrind fixes from jemalloc 3.4.1
extra/jemalloc/include/jemalloc/internal/tcache.h:
Backported valgrind fixes from jemalloc 3.4.1
extra/jemalloc/src/arena.c:
Backported valgrind fixes from jemalloc 3.4.1
include/my_bitmap.h:
Renamed bitmap_init() and bitmap_free() to my_bitmap_init() and my_bitmap_free() to avoid clash with jemalloc 3.4.1
mysql-test/mysql-test-run.pl:
Use option --soname-synonyms=somalloc=NON to valgrind when using jemalloc
mysql-test/valgrind.supp:
Supression of memory leak in OpenSuse 12.3
mysys/my_bitmap.c:
Renamed bitmap_init() and bitmap_free() to my_bitmap_init() and my_bitmap_free()
sql/ha_ndbcluster_binlog.cc:
Renames
sql/ha_ndbcluster_cond.h:
Renames
sql/ha_partition.cc:
Renames
sql/handler.cc:
Renames
sql/item_subselect.cc:
Renames
sql/log_event.cc:
Renames
sql/log_event_old.cc:
Renames
sql/mysqld.cc:
Renames
Show version related variables in mysqld --help
sql/opt_range.cc:
Renames
sql/opt_table_elimination.cc:
Renames
sql/partition_info.cc:
Renames
sql/rpl_injector.h:
Renames
sql/set_var.h:
Renames
sql/slave.cc:
Renames
sql/sql_bitmap.h:
Renames
sql/sql_insert.cc:
Renames
sql/sql_lex.h:
Renames
sql/sql_parse.cc:
Renames
sql/sql_partition.cc:
Renames
sql/sql_select.cc:
Renames
sql/sql_show.cc:
Renames
sql/sql_update.cc:
Renames
sql/sys_vars.cc:
Show version related variables in mysqld --help
sql/sys_vars.h:
Added SHOW_VALUE_IN_HELP marker for variables that should be shown in --help
sql/table.cc:
Renames
sql/table.h:
Removed not used bitmap_init_value
storage/connect/ha_connect.cc:
Removed compiler warning
storage/maria/ma_open.c:
Renames
unittest/mysys/bitmap-t.c:
Renames
The earlier pushed fix for the bug was incomplete. It did not remove
the main cause of the problem: the function remove_eq_conds()
removed always true multiple equalities from any conjunct, but did not
adjust the list of them stored in Item_cond_and::cond_equal.current_level.
Simplified the test case for the bug and moved it to another test file.
The fix triggered changes in EXPLAIN EXTENDED for some queries.
- Don't pull out a table out of a semi-join if it is on the inner side of an outer join.
- Make join->sort_by_table= get_sort_by_table(...) call after const table detection
is done. That way, the value of join->sort_by_table will match the actual execution.
Which will allow the code in setup_semijoin_dups_elimination() (search for
"Make sure that possible sorting of rows from the head table is not to be employed."
to see that "Using filesort" is going to be used together with Duplicate Elimination (
and change it to Using temporary + Using filesort)
- make_join_readinfo() has the code that forces use of "Using temporary;
Using filesort" when join buffering is in use.
That code didn't handle all cases, in particular it didn't hande the case
where ORDER BY originally has tables from multiple columns, but the
optimizer eventually figures out that doing filesort() on one table
will be sufficient. Adjusted the code to handle that case.
Apply fix suggested by Igor:
- When eliminate_item_equal() generates pair-wise equalities from a
multi-equality, do generate a "bridge" equality between the first
field inside SJM nest and the field that's first in the overall multi-equality.
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.
BNL and BNLH joins pre-filter the records from a joined table via JOIN_TAB::cache_select->cond.
There is no need to re-evaluate the same conditions via JOIN_TAB::select_cond. This patch removes
the duplicated conditions from the top-level conjuncts of each pushed condition.
The added "Using where" in few EXPLAINs is due to taking into account tab->cache_select->cond
in addition to tab->select_cond in JOIN::save_explain_data_intern.
depends on uninitialised value(s) in JOIN::save_explain_data_intern"
- Make find_best() /* the old join optimizer code */ also use table
condition selectivity.
- It turns out, there are statements that will call lex_start(thd->lex)
after parsing has been finished. lex_start() will set lex->explain=NULL,
which will lose the pointer to already allocated Explain_plan object.
- To get rid of this, switch to lazy creation of lex->explain. Now, it is
created only when we get a part ot query plan.
Update the SHOW EXPLAIN code to work with the
new architecture (part#1):
Before, SHOW EXPLAIN operated on real query plan structures,
which meant it had to check when SELECTs are created/deleted.
SELECTs would call apc_target->enable() when they got a query
plan and disable() when their query plan was deleted.
Now, Explain data structure becomes available at once (and we
call apc_target->enable()) and then it stays until it is deleted
(when that happens, we call apc_target->disable()).
