Analysis:
The assert failed because the execution code for
partial matching is designed with the assumption that
NULLs on the left side are detected as early as possible,
and a NULL result is returned before any lookups are
performed at all.
However, in the case of an Item_cache object on the left
side, null was not detected properly, because detection
was done via Item::is_null(), which is not implemented at
all for Item_cache, and resolved to the default Item::is_null()
which always returns FALSE.
Solution:
Use the property Item::null_value instead of is_null(), which
is properly updated for Item_cache objects as well.
Analysis:
The reason for the crash was that the inner subquery was executed
via a scan on a final temporary table applied after all other
operations. This final operation is implemented by changing the
contents of the JOIN object of the subquery to represent a table
scan over the temp table. At the same time query optimization of
the outer subquery required evaluation of the inner subquery, which
happened before the actual EXPLAIN. The evaluation left the JOIN
object of the inner subquery in the changed state, where it represented
a table scan over a temp table, and EXPLAIN crashed because the temp
table is not associated with any table reference (TABLE_LIST object).
The reason the JOIN was not restored was because its saving/restoration
was controlled by the join->select_lex->uncacheable flag, which was
not set in the case of materialization.
Solution:
In the methods Item_in_subselect::[single | row]_value_transformer() set:
select_lex->uncacheable|= UNCACHEABLE_EXPLAIN;
In addition, for symmetry, change:
master_unit->uncacheable|= UNCACHEABLE_EXPLAIN;
instead of UNCACHEABLE_DEPENDENT because if a subquery was not
dependent initially, the changed methods do not change this
fact. The subquery may later become correlated if it is transformed
to an EXISTS query, but it may stay uncorrelated if executed via
materialization.
- Fixed some issues with partitions and connection_string, which also fixed lp:716890 "Pre- and post-recovery crash in Aria"
- Fixed wrong assert in Aria
Now need to merge with latest xtradb before pushing
sql/ha_partition.cc:
Ensure that m_ordered_rec_buffer is not freed before close.
sql/mysqld.cc:
Changed to use opt_stack_trace instead of opt_pstack.
Removed references to pstack
sql/partition_element.h:
Ensure that connect_string is initialized
storage/maria/ma_key_recover.c:
Fixed wrong assert
- Removed files specific to compiling on OS/2
- Removed files specific to SCO Unix packaging
- Removed "libmysqld/copyright", text is included in documentation
- Removed LaTeX headers for NDB Doxygen documentation
- Removed obsolete NDB files
- Removed "mkisofs" binaries
- Removed the "cvs2cl.pl" script
- Changed a few GPL texts to use "program" instead of "library"
Analysis:
The assert failed because st_select_lex::print() was called for subqueries
as follows:
Item_subselect::print() ->
subselect_single_select_engine::print() -> st_select_lex::print()
It was Item_subselect::fix_fields() that set the thd by calling set_thd(),
so when this print() was called before fix_fields(), subselect_engine::thd
was NULL.
Solution:
The patch makes all constructors of all subselect_engine classes to take
a THD parameter. The default subselect_single_select_engine engine is created
early during parse time, in the Item_subselect::init call, so we pass the
correct THD object already at this point.
--Bug#52157 various crashes and assertions with multi-table update, stored function
--Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb
--Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846
--Bug#57352 valgrind warnings when creating view
--Recently discovered problem when a nested materialized derived table is used
before being populated and it leads to incorrect result
We have several modes when we should disable subquery evaluation.
The reasons for disabling are different. It could be
uselessness of the evaluation as in case of 'CREATE VIEW'
or 'PREPARE stmt', or we should disable subquery evaluation
if tables are not locked yet as it happens in bug#54475, or
too early evaluation of subqueries can lead to wrong result
as it happened in Bug#19077.
Main problem is that if subquery items are treated as const
they are evaluated in ::fix_fields(), ::fix_length_and_dec()
of the parental items as a lot of these methods have
Item::val_...() calls inside.
We have to make subqueries non-const to prevent unnecessary
subquery evaluation. At the moment we have different methods
for this. Here is a list of these modes:
1. PREPARE stmt;
We use UNCACHEABLE_PREPARE flag.
It is set during parsing in sql_parse.cc, mysql_new_select() for
each SELECT_LEX object and cleared at the end of PREPARE in
sql_prepare.cc, init_stmt_after_parse(). If this flag is set
subquery becomes non-const and evaluation does not happen.
2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which
process FRM files
We use LEX::view_prepare_mode field. We set it before
view preparation and check this flag in
::fix_fields(), ::fix_length_and_dec().
Some bugs are fixed using this approach,
some are not(Bug#57352, Bug#57703). The problem here is
that we have a lot of ::fix_fields(), ::fix_length_and_dec()
where we use Item::val_...() calls for const items.
3. Derived tables with subquery = wrong result(Bug19077)
The reason of this bug is too early subquery evaluation.
It was fixed by adding Item::with_subselect field
The check of this field in appropriate places prevents
const item evaluation if the item have subquery.
The fix for Bug19077 fixes only the problem with
convert_constant_item() function and does not cover
other places(::fix_fields(), ::fix_length_and_dec() again)
where subqueries could be evaluated.
Example:
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
DROP TABLE t1;
4. Derived tables with subquery where subquery
is evaluated before table locking(Bug#54475, Bug#52157)
Suggested solution is following:
-Introduce new field LEX::context_analysis_only with the following
possible flags:
#define CONTEXT_ANALYSIS_ONLY_PREPARE 1
#define CONTEXT_ANALYSIS_ONLY_VIEW 2
#define CONTEXT_ANALYSIS_ONLY_DERIVED 4
-Set/clean these flags when we perform
context analysis operation
-Item_subselect::const_item() returns
result depending on LEX::context_analysis_only.
If context_analysis_only is set then we return
FALSE that means that subquery is non-const.
As all subquery types are wrapped by Item_subselect
it allow as to make subquery non-const when
it's necessary.
mysql-test/r/derived.result:
test case
mysql-test/r/multi_update.result:
test case
mysql-test/r/view.result:
test case
mysql-test/suite/innodb/r/innodb_multi_update.result:
test case
mysql-test/suite/innodb/t/innodb_multi_update.test:
test case
mysql-test/suite/innodb_plugin/r/innodb_multi_update.result:
test case
mysql-test/suite/innodb_plugin/t/innodb_multi_update.test:
test case
mysql-test/t/derived.test:
test case
mysql-test/t/multi_update.test:
test case
mysql-test/t/view.test:
test case
sql/item.cc:
--removed unnecessary code
sql/item_cmpfunc.cc:
--removed unnecessary checks
--THD::is_context_analysis_only() is replaced with LEX::is_ps_or_view_context_analysis()
sql/item_func.cc:
--refactored context analysis checks
sql/item_row.cc:
--removed unnecessary checks
sql/item_subselect.cc:
--removed unnecessary code
--added DBUG_ASSERT into Item_subselect::exec()
which asserts that subquery execution can not happen
if LEX::context_analysis_only is set, i.e. at context
analysis stage.
--Item_subselect::const_item()
Return FALSE if LEX::context_analysis_only is set.
It prevents subquery evaluation in ::fix_fields &
::fix_length_and_dec at context analysis stage.
sql/item_subselect.h:
--removed unnecessary code
sql/mysql_priv.h:
--Added new set of flags.
sql/sql_class.h:
--removed unnecessary code
sql/sql_derived.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_lex.cc:
--init LEX::context_analysis_only field
sql/sql_lex.h:
--New LEX::context_analysis_only field
sql/sql_parse.cc:
--removed unnecessary code
sql/sql_prepare.cc:
--removed unnecessary code
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_select.cc:
--refactored context analysis checks
sql/sql_show.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_view.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
- Fixed problem with oqgraph and 'make dist'
Note that after this merge we have a problem show in join_outer where we examine too many rows in one specific case (related to BUG#57024).
This will be fixed when mwl#128 is merged into 5.3.
Changed rows_read and rows_sent status variables to be longlong (to avoid compiler warnings)
sql/item_func.cc:
Fixed wrong usage of alias
sql/item_subselect.cc:
Changed buffer size to ulonglong to be able detect buffers bigger than size_t
sql/item_subselect.h:
Changed buffer size to ulonglong to be able detect buffers bigger than size_t
sql/multi_range_read.cc:
Fixed compiler warning by using correct type for function argument
sql/mysqld.cc:
Changed rows_read and rows_sent status variables to be longlong
sql/opt_subselect.h:
Fixed compiler warning by using correct type for function argument
sql/sql_class.cc:
Changed rows_read and rows_sent status variables to be longlong
sql/sql_class.h:
Changed rows_read and rows_sent status variables to be longlong
Changed max_nulls_in_row to uint as this is number of columns in row.
This fixed some compiler warnings.
sql/sql_select.cc:
Added casts to avoid compiler warnings
storage/heap/ha_heap.cc:
Initilize different types separate
storage/oqgraph/ha_oqgraph.cc:
Fixed argument to store(longlong) to avoid compiler warnings
Open issues:
- A better fix for #57688; Igor is working on this
- Test failure in index_merge_innodb.test ; Igor promised to look at this
- Some Innodb tests fails (need to merge with latest xtradb) ; Kristian promised to look at this.
- Failing tests: innodb_plugin.innodb_bug56143 innodb_plugin.innodb_bug56632 innodb_plugin.innodb_bug56680 innodb_plugin.innodb_bug57255
- Werror is disabled; Should be enabled after merge with xtradb.
The set of Ordered keys of a rowid merge engine is dense. Thus when
we decide not to create a key for a column that has only NULLs, this
column shouldn't be counted.
Notice that the caller has already precomputed the correct total
number of keys that should be created.
The cause for this bug is that MariaDB 5.3 still processes derived tables
(subqueries in the FROM clause) by fully executing them during the parse
phase. This will be remedied by MWL#106 once merged into the main 5.3.
The assert statement is triggered when MATERIALIZATION is ON for EXPLAIN
EXTENDED for derived tables with an IN subquery as follows:
- mysql_parse calls JOIN::exec for the derived table as if it is regular
execution (not explain).
- When materialization is ON, this call goes all the way to
subselect_hash_sj_engine::exec, which creates a partial match engine
because of NULL presence.
- In order to proceed with normal execution, the hash_sj engine substitutes
itself with the created partial match engine.
- After the parse phase it turns out that this execution was part of
EXPLAIN EXTENDED, which in turn calls
Item_cond::print -> ... -> Item_subselect::print,
which calls engine->print().
Since subselect_hash_sj_engine::exec substituted the current
Item_subselect engine with a partial match engine, eventually we call
its ::print() method. However the partial match engines are designed only
for execution, hence there is no implementation of this print() method.
The fix temporarily removes the assert, until this code is merged with
MWL#106.
create_sort_index() function overwrites original JOIN_TAB::type field.
At re-execution of subquery overwritten JOIN_TAB::type(JT_ALL) is
used instead of JT_FT. It misleads test_if_skip_sort_order() and
the function tries to find suitable key for the order that should
not be allowed for FULLTEXT(JT_FT) table.
The fix is to restore JOIN_TAB strucures for subselect on re-execution
for EXPLAIN.
Additional fix:
Update TABLE::maybe_null field which
affects list_contains_unique_index() behaviour as it
could have the value(maybe_null==TRUE) based on the
assumption that this join is outer
(see setup_table_map() func).
mysql-test/r/explain.result:
test case
mysql-test/t/explain.test:
test case
sql/item_subselect.cc:
Make subquery uncacheable in case of EXPLAIN. It allows to keep
original JOIN_TAB::type(see JOIN::save_join_tab) and restore it
on re-execution.
sql/sql_select.cc:
-restore JOIN_TAB strucures for subselect on re-execution for EXPLAIN
-Update TABLE::maybe_null field as it could have
the value(maybe_null==TRUE) based on the assumption
that this join is outer(see setup_table_map() func).
This change is not related to the crash problem but
affects EXPLAIN results in the test case.
The crash happens because original join table is replaced with temporary table
at execution stage and later we attempt to use this temporary table in
select_describe. It might happen that
Item_subselect::update_used_tables() method which sets const_item flag
is not called by some reasons (no where/having conditon in subquery for example).
It prevents JOIN::join_tmp creation and breaks original join.
The fix is to call ::update_used_tables() before ::const_item() check.
mysql-test/r/ps.result:
test case
mysql-test/t/ps.test:
test case
sql/item_subselect.cc:
call ::update_used_tables() before ::const_item() check.
result
Row subqueries producing no rows were not handled as UNKNOWN
values in row comparison expressions.
That was a result of the following two problems:
1. Item_singlerow_subselect did not mark the resulting row
value as NULL/UNKNOWN when no rows were produced.
2. Arg_comparator::compare_row() did not take into account that
a whole argument may be NULL rather than just individual scalar
values.
Before bug#34384 was fixed, the above problems were hidden
because an uninitialized (i.e. without any stored value) cached
object would appear as NULL for scalar values in a row subquery
returning an empty result. After the fix
Arg_comparator::compare_row() would try to evaluate
uninitialized cached objects.
Fixed by removing the aforementioned problems.
mysql-test/r/row.result:
Added a test case for bug #54190.
mysql-test/r/subselect.result:
Updated the result for a test relying on wrong behavior.
mysql-test/t/row.test:
Added a test case for bug #54190.
sql/item_cmpfunc.cc:
If either of the argument rows is NULL, return NULL as the
result of comparison.
sql/item_subselect.cc:
Adjust null_value for Item_singlerow_subselect depending on
whether a row has been produced by the row subquery.
The EXISTS transformation has additional switches to catch the known corner
cases that appear when transforming an IN predicate into EXISTS. Guarded
conditions are used which are deactivated when a NULL value is seen in the
outer expression's row. When the inner query block supplies NULL values,
however, they are filtered out because no distinction is made between the
guarded conditions; guarded NOT x IS NULL conditions in the HAVING clause that
filter out NULL values cannot be de-activated in isolation from those that
match values or from the outer expression or NULL's.
The above problem is handled by making the guarded conditions remember whether
they have rejected a NULL value or not, and index access methods are taking
this into account as well.
The bug consisted of
1) Not resetting the property for every nested loop iteration on the inner
query's result.
2) Not propagating the NULL result properly from inner query to IN optimizer.
3) A hack that may or may not have been needed at some point. According to a
comment it was aimed to fix#2 by returning NULL when FALSE was actually
the result. This caused failures when #2 was properly fixed. The hack is
now removed.
The fix resolves all three points.
The bug is a result of the following change by Monty:
Revision Id: monty@askmonty.org-20100716073301-gstby2062nqd42qv
Timestamp: Fri 2010-07-16 10:33:01 +0300
Where Monty changed the queues interface and implementation.
The fix adjusts the queue_remove call to the new interface.
mysql-test/r/subselect_partial_match.result:
Added new file for tests related to MWL#89.
mysql-test/t/subselect_partial_match.test:
Added new file for tests related to MWL#89.
The issue was that we didn't always check result of ha_rnd_init() which caused a problem for handlers that returned an error in this code.
- Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked.
- Added ha_rnd_init_with_error() that prints error on failure.
- Checked all usage of ha_rnd_init() and ensure we generate an error message on failures.
- Changed init_read_record() to return 1 on failure.
sql/create_options.cc:
Fixed wrong printf
sql/event_db_repository.cc:
Check result from init_read_record()
sql/events.cc:
Check result from init_read_record()
sql/filesort.cc:
Check result from ha_rnd_init()
sql/ha_partition.cc:
Check result from ha_rnd_init()
sql/ha_partition.h:
Fixed compiler warning
sql/handler.cc:
Added ha_rnd_init_with_error()
Check result from ha_rnd_init()
sql/handler.h:
Added ha_rnd_init_with_error()
Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked
sql/item_subselect.cc:
Check result from ha_rnd_init()
sql/log.cc:
Check result from ha_rnd_init()
sql/log_event.cc:
Check result from ha_rnd_init()
sql/log_event_old.cc:
Check result from ha_rnd_init()
sql/mysql_priv.h:
init_read_record() now returns error code on failure
sql/opt_range.cc:
Check result from ha_rnd_init()
sql/records.cc:
init_read_record() now returns error code on failure
Check result from ha_rnd_init()
sql/sql_acl.cc:
Check result from init_read_record()
sql/sql_cursor.cc:
Print error if ha_rnd_init() fails
sql/sql_delete.cc:
Check result from init_read_record()
sql/sql_help.cc:
Check result from init_read_record()
sql/sql_plugin.cc:
Check result from init_read_record()
sql/sql_select.cc:
Check result from ha_rnd_init()
Print error if ha_rnd_init() fails.
sql/sql_servers.cc:
Check result from init_read_record()
sql/sql_table.cc:
Check result from init_read_record()
sql/sql_udf.cc:
Check result from init_read_record()
sql/sql_update.cc:
Check result from init_read_record()
storage/example/ha_example.cc:
Don't return error on rnd_init()
storage/ibmdb2i/ha_ibmdb2i.cc:
Removed not relevant comment
Fixed compiler warnings.
queues.h and queues.c are now based on the UNIREG code and thus made BSD.
Fix code to use new queue() interface. This mostly affects how you access elements in the queue.
If USE_NET_CLEAR is not set, don't clear connection from unexpected characters. This should give a speed up when doing a lot of fast queries.
Fixed some code in ma_ft_boolean_search.c that had not made it from myisam/ft_boolean_search.c
include/queues.h:
Use UNIREG code base (BSD)
Changed init_queue() to take all initialization arguments.
New interface to access elements in queue
include/thr_alarm.h:
Changed to use time_t instead of ulong (portability)
Added index_in_queue, to be able to remove random element from queue in O(1)
mysys/queues.c:
Use UNIREG code base (BSD)
init_queue() and reinit_queue() now takes more initialization arguments. (No need for init_queue_ex() anymore)
Now one can tell queue_insert() to store in the element a pointer to where element is in queue. This allows one to remove elements from queue in O(1) instead of O(N)
mysys/thr_alarm.c:
Use new option in queue() to allow fast removal of elements.
Do less inside LOCK_alarm mutex.
This should give a major speed up of thr_alarm usage when there is many threads
sql/create_options.cc:
Fixed wrong printf
sql/event_queue.cc:
Use new queue interface()
sql/filesort.cc:
Use new queue interface()
sql/ha_partition.cc:
Use new queue interface()
sql/ha_partition.h:
Fixed compiler warning
sql/item_cmpfunc.cc:
Fixed compiler warning
sql/item_subselect.cc:
Use new queue interface()
Removed not used variable
sql/net_serv.cc:
If USE_NET_CLEAR is not set, don't clear connection from unexpected characters.
This should give a speed up when doing a lot of fast queries at the disadvantage that if there is a bug in the client protocol the connection will be dropped instead of being unnoticed.
sql/opt_range.cc:
Use new queue interface()
Fixed compiler warnings
sql/uniques.cc:
Use new queue interface()
storage/maria/ma_ft_boolean_search.c:
Copy code from myisam/ft_boolean_search.c
Use new queue interface()
storage/maria/ma_ft_nlq_search.c:
Use new queue interface()
storage/maria/ma_sort.c:
Use new queue interface()
storage/maria/maria_pack.c:
Use new queue interface()
Use queue_fix() instead of own loop to fix queue.
storage/myisam/ft_boolean_search.c:
Use new queue interface()
storage/myisam/ft_nlq_search.c:
Use new queue interface()
storage/myisam/mi_test_all.sh:
Remove temporary file from last run
storage/myisam/myisampack.c:
Use new queue interface()
Use queue_fix() instead of own loop to fix queue.
storage/myisam/sort.c:
Use new queue interface()
storage/myisammrg/myrg_queue.c:
Use new queue interface()
storage/myisammrg/myrg_rnext.c:
Use new queue interface()
storage/myisammrg/myrg_rnext_same.c:
Use new queue interface()
storage/myisammrg/myrg_rprev.c:
Use new queue interface()
libmysqld/Makefile.am:
The new file added.
mysql-test/r/index_merge_myisam.result:
subquery_cache optimization option added.
mysql-test/r/myisam_mrr.result:
subquery_cache optimization option added.
mysql-test/r/subquery_cache.result:
The subquery cache tests added.
mysql-test/r/subselect3.result:
Subquery cache switched off to avoid changing read statistics.
mysql-test/r/subselect3_jcl6.result:
Subquery cache switched off to avoid changing read statistics.
mysql-test/r/subselect_no_mat.result:
subquery_cache optimization option added.
mysql-test/r/subselect_no_opts.result:
subquery_cache optimization option added.
mysql-test/r/subselect_no_semijoin.result:
subquery_cache optimization option added.
mysql-test/r/subselect_sj.result:
subquery_cache optimization option added.
mysql-test/r/subselect_sj_jcl6.result:
subquery_cache optimization option added.
mysql-test/t/subquery_cache.test:
The subquery cache tests added.
mysql-test/t/subselect3.test:
Subquery cache switched off to avoid changing read statistics.
sql/CMakeLists.txt:
The new file added.
sql/Makefile.am:
The new files added.
sql/item.cc:
Expression cache item (Item_cache_wrapper) added.
Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP.
sql/item.h:
Expression cache item (Item_cache_wrapper) added.
Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP.
sql/item_cmpfunc.cc:
Subquery cache added.
sql/item_cmpfunc.h:
Subquery cache added.
sql/item_subselect.cc:
Subquery cache added.
sql/item_subselect.h:
Subquery cache added.
sql/item_sum.cc:
Registration of subquery parameters added.
sql/mysql_priv.h:
subquery_cache optimization option added.
sql/mysqld.cc:
subquery_cache optimization option added.
sql/opt_range.cc:
Fix due to subquery cache.
sql/opt_subselect.cc:
Parameters of the function cahnged.
sql/procedure.h:
.h file guard added.
sql/sql_base.cc:
Registration of subquery parameters added.
sql/sql_class.cc:
Option to allow add indeces to temporary table.
sql/sql_class.h:
Item iterators added.
Option to allow add indeces to temporary table.
sql/sql_expression_cache.cc:
Expression cache for caching subqueries added.
sql/sql_expression_cache.h:
Expression cache for caching subqueries added.
sql/sql_lex.cc:
Registration of subquery parameters added.
sql/sql_lex.h:
Registration of subqueries and subquery parameters added.
sql/sql_select.cc:
Subquery cache added.
sql/sql_select.h:
Subquery cache added.
sql/sql_union.cc:
A new parameter to the function added.
sql/sql_update.cc:
A new parameter to the function added.
sql/table.cc:
Procedures to manage temporarty tables index added.
sql/table.h:
Procedures to manage temporarty tables index added.
storage/maria/ha_maria.cc:
Fix of handler to allow destoy a table in case of error during the table creation.
storage/maria/ha_maria.h:
.h file guard added.
storage/myisam/ha_myisam.cc:
Fix of handler to allow destoy a table in case of error during the table creation.
- Item_in_subselect::init_left_expr_cache() should not try to
guess whether the left expression is accessed "over the grouping operation"
(i.e. the subselect is evaluated after the grouping while the left_expr is
an Item_ref that wraps an expression from before the grouping). Instead,
let new_Cached_item not to try accessing item->real_item() when creating
left expr cache.
strict aliasing violations.
One somewhat major source of strict-aliasing violations and
related warnings is the SQL_LIST structure. For example,
consider its member function `link_in_list` which takes
a pointer to pointer of type T (any type) as a pointer to
pointer to unsigned char. Dereferencing this pointer, which
is done to reset the next field, violates strict-aliasing
rules and might cause problems for surrounding code that
uses the next field of the object being added to the list.
The solution is to use templates to parametrize the SQL_LIST
structure in order to deference the pointers with compatible
types. As a side bonus, it becomes possible to remove quite
a few casts related to acessing data members of SQL_LIST.
sql/handler.h:
Use the appropriate template type argument.
sql/item.cc:
Remove now-unnecessary cast.
sql/item_subselect.cc:
Remove now-unnecessary casts.
sql/item_sum.cc:
Use the appropriate template type argument.
Remove now-unnecessary cast.
sql/mysql_priv.h:
Move SQL_LIST structure to sql_list.h
Use the appropriate template type argument.
sql/sp.cc:
Remove now-unnecessary casts.
sql/sql_delete.cc:
Use the appropriate template type argument.
Remove now-unnecessary casts.
sql/sql_derived.cc:
Remove now-unnecessary casts.
sql/sql_lex.cc:
Remove now-unnecessary casts.
sql/sql_lex.h:
SQL_LIST now takes a template type argument which must
match the type of the elements of the list. Use forward
declaration when the type is not available, it is used
in pointers anyway.
sql/sql_list.h:
Rename SQL_LIST to SQL_I_List. The template parameter is
the type of object that is stored in the list.
sql/sql_olap.cc:
Remove now-unnecessary casts.
sql/sql_parse.cc:
Remove now-unnecessary casts.
sql/sql_prepare.cc:
Remove now-unnecessary casts.
sql/sql_select.cc:
Remove now-unnecessary casts.
sql/sql_show.cc:
Remove now-unnecessary casts.
sql/sql_table.cc:
Remove now-unnecessary casts.
sql/sql_trigger.cc:
Remove now-unnecessary casts.
sql/sql_union.cc:
Remove now-unnecessary casts.
sql/sql_update.cc:
Remove now-unnecessary casts.
sql/sql_view.cc:
Remove now-unnecessary casts.
sql/sql_yacc.yy:
Remove now-unnecessary casts.
storage/myisammrg/ha_myisammrg.cc:
Remove now-unnecessary casts.
Fixed some bugs introduced in 5.1.47
Disabled some tests until we have merged with latest Xtradb
configure.in:
Added testing if valgrind/memcheck.h exists
storage/pbxt/src/ha_pbxt.cc:
LOCK_plugin is not anymore locked in init
We should disable const subselect item evaluation because
subselect transformation does not happen in view_prepare_mode
and thus val_...() methods can not be called.
mysql-test/r/ctype_ucs.result:
test case
mysql-test/r/view.result:
test case
mysql-test/t/ctype_ucs.test:
test case
mysql-test/t/view.test:
test case
sql/item.cc:
disabled const subselect item evaluation in
view prepare mode.
sql/item_subselect.cc:
added Item_subselect::safe_charset_converter which
prevents const item evaluation in view prepare mode.
sql/item_subselect.h:
added Item_subselect::safe_charset_converter which
prevents const item evaluation in view prepare mode.
- Add Item_in_subselect::get_identifier() that returns subquery's id
- Change select_describe() to produce output in new format
- Update test results (checked)
query:
- When subquery is located in ORDER BY, EXPLAIN will run as follows:
select_describe() will run JOIN::prepare()/optimize() for the subquery;
then at some point subselect_single_select_engine::prepare() will be called,
which will create another join and run join->prepare().
In mainline mysql this is not a problem because subquery's join will be
destroyed after the first call.
In MariaDB, it won't (table elimination needs to keep JOIN objects around
for longer in order to know which tables were eliminated when constructing
EXPLAIN EXTENDED warning).
Fix the problem of memory leak by calling select_lex->cleanup() in
subselect_single_select_engine::prepare().
Bug#46949: memory leak with failed alter table to create partitions based on extract()
Bug#51830: Incorrect partition pruning on range partition (regression)
Fixed valgrind failure in select_describe(), read of uninitialized
Item_subselect::eliminated.
PBXT test file updates to reflect changes done in MySQL.
mysql-test/suite/pbxt/r/partition_error.result:
Result file update following MySQL 5.1.44 changes.
mysql-test/suite/pbxt/r/partition_pruning.result:
Result file update following MySQL 5.1.44 changes.
mysql-test/suite/pbxt/t/partition_error.test:
Test file update following MySQL 5.1.44 changes.
sql/item_subselect.cc:
Fixed valgrind failure in select_describe(), read of uninitialized
Item_subselect::eliminated:
- it turns out we can call select_describe() without having fixed
subquery items for child subselects. These are not the kind of subqueries
that we could eliminate, so the fix is to ensure that
item_subselect->eliminated==FALSE even before fix_fields is called.
Also added code to reset item_subselect->eliminated back to FALSE in
Item::reset() call.
sql/item_subselect.h:
Fixed valgrind failure in select_describe(), read of uninitialized
Item_subselect::eliminated:
- it turns out we can call select_describe() without having fixed
subquery items for child subselects. These are not the kind of subqueries
that we could eliminate, so the fix is to ensure that
item_subselect->eliminated==FALSE even before fix_fields is called.
Also added code to reset item_subselect->eliminated back to FALSE in
Item::reset() call.
sql/sql_partition.cc:
Fix Bug#51830: Revert part of the patch for Bug#49742, which caused the regression.
sql/table.cc:
Fix Bug#46949: memory leak in failed ALTER TABLE with partitioning.
The problem was that killing a query during the optimization
phase of a subselect would lead to crashes. The root of the
problem is that the subselect execution engine ignores failures
(eg: killed) during the optimization phase (JOIN::optimize),
leading to a crash once the subquery is executed due to
partially initialized structures (in this case a join tab).
The optimal solution would be to cleanup certain optimizer
structures if the optimization phase fails, but currently
there is no infrastructure to properly to track and cleanup
the structures. To workaround the whole problem one somewhat
good solution is to avoid executing a subselect if the query
has been killed. Cutting short any problems caused by failures
during the optimization phase.
sql/item_subselect.cc:
Do not execute a subselect if the session or query has been killed.
* Implemented a second partial matching strategy via table scan.
This strategy is a fallback when there is no memory for rowid merging.
* Refactored the selection and creation of partial matching strategies,
so that the choice of strategy is encapsulated in a separate method
choose_partial_match_strategy().
* Refactored the representation of partial match strategies so that:
- each strategy is represented by a polymorphic class, and
- the base class for all partial match strategies contains common
execution code.
* Added an estimate of the memory needed for the rowid merge strategy,
and the system variable "rowid_merge_buff_size" to control the maximum
memory to be used by the rowid merge algorithm.
* Added two optimizer_switch system variables to control the choice of
partial match strategy:
"partial_match_rowid_merge", "partial_match_table_scan".
* Fixed multiple problems with deallocation of resources by the partial
match strategies.
sql/mysql_priv.h:
* Added two optimizer_switch system variables to control the choice of
partial match strategy:
"partial_match_rowid_merge", "partial_match_table_scan".
sql/mysqld.cc:
* Added two optimizer_switch system variables to control the choice of
partial match strategy:
"partial_match_rowid_merge", "partial_match_table_scan".
* Added a system variable "rowid_merge_buff_size" to control the maximum
memory to be used by the rowid merge algorithm.
sql/set_var.cc:
* Added a system variable "rowid_merge_buff_size" to control the maximum
memory to be used by the rowid merge algorithm.
sql/sql_class.h:
* Added a system variable "rowid_merge_buff_size" to control the maximum
memory to be used by the rowid merge algorithm.
support-files/build-tags:
Newer versions of BZR require the recursive flag in order to list all files.
If an outer query is broken, a subquery might not even get set up.
EXPLAIN EXTENDED did not expect this and merrily tried to de-ref all
of the half-setup info.
We now catch this case and print as much as we have, as it doesn't cost us
anything (doesn't make regular execution slower).
backport from 5.1
mysql-test/r/explain.result:
Show that EXPLAIN EXTENDED with subquery and illegal out query doesn't crash.
Show also that SHOW WARNINGS will render an additional Note in the hope of
being, well, helpful.
mysql-test/t/explain.test:
If we have only half a query for EXPLAIN EXTENDED to print (i.e.,
incomplete subquery info as outer query is illegal), we should
provide the user with as much info as we easily can if they ask
for it. What we should not do is crash when they come asking for
help, that violates etiquette in some countries.
sql/item_subselect.cc:
If the sub-query's actually set up, print it. Otherwise, elide.
This patch mainly adds sorting of all indexes for partial matching
according to their NULL selectivity. The patch also fixes a related bug
in subselect_rowid_merge_engine::test_null_row() where the wrong matched
indexes were skipped.
In addition the patch:
- adds few ::print() methods,
- renames few variables that had similar names but different purpose.
In Item_ref::fix_fields() do invoke mark_as_dependent() for outside
references in all cases (see email for more details)
sql/item.cc:
In Item_ref::fix_fields() do invoke mark_as_dependent() for outside references in all cases.
sql/item.h:
Change Field_enumerator to enumerate Item_field-s not Field-s.
sql/item_subselect.cc:
Change Field_enumerator to enumerate Item_field-s not Field-s.
sql/opt_table_elimination.cc:
Change Field_enumerator to enumerate Item_field-s not Field-s.
