after all engines have discovered their tables
side effect: correct alphabetical sorting as in ORDER BY ... COLLATE utf8_bin,
information_schema is no longer the first after find_files(),
tables like #mysql50#zzz are sorted first (as per table name),
not last (as per file name zzz).
mysqltest: At line 477: query 'show explain for $thr2' failed: 1933: Target is not running an EXPLAINable command
After the fix for MDEV-4144, subquery with WHERE pk= (select ...) became a degenerate, constant
SELECT. It is not executed in normal way anymore, so it is not possible to catch it in-execution.
Analysis:
The reason for the inefficent plan was that Item_subselect::is_expensive()
didn't detect the special case when a subquery was optimized, but had no
join plan because it either has no table, or its tables have been optimized
away, or the optimizer detected that the result set is empty.
Solution:
Identify the special cases above in the Item_subselect::is_expensive(),
and consider such degenerate subqueries inexpensive.
This bug was introduced by the patch for WL#3220.
If the memory allocated for the tree to store unique elements
to be counted is not big enough to include all of them then
an external file is used to store the elements.
The unique elements are guaranteed not to be nulls. So, when
reading them from the file we don't have to care about the null
flags of the read values. However, we should remove the flag
at the very beginning of the process. If we don't do it and
if the last value written into the record buffer for the field
whose distinct values needs to be counted happens to be null,
then all values read from the file are considered to be nulls
and are not counted in.
The fix does not remove a possible null flag for the read values.
Rather it just counts the values in the same way it was done
before WL #3220.
During server shutdown, we need to wait for binlog checkpointing to
finish in the binlog background thread before closing the binlog.
This was not done, so we could get assert and failure to finish the
final binlog checkpoint if shutdown happened in the middle.
-Change my_rnd() slightly to make it safer if two threads use it at the same time.
-Avoid some sprintf and strmov in vio.
-Changed thread_count to be automaticly incremented (instead of under LOCK_thread_count).
-Thread cache now uses LOCK_thread_cache instead of LOCK_thread_count.
-Moved delete thd out from LOCK_thread_count.
-Save some mysql_cond_broadcast(&COND_thread_count) calls.
-Removed call to getsockname() during connect.
-Initialize random generator without locks.
Other things:
-Fixed test cases that depends on changes for LOCK_grant
-Added thread_safe_decrement32() and thread_safe_increment32()
-Removed sql_rnd_with_mutex() and get_thread_running()
-In check_table_access() don't lock LOCK_grant if we can resolve the grant with user or db level grants (the normal case).
-Don't use a lock for setting THD->query_id.
-Fixed bug where thd->set_query_id() could be set to same value by multiple threads.
Thanks to Yoshinori Matsunobu for the benchmark of connection speed and to
Domas Mituzas for the inspiration for many of the fixes.
include/violite.h:
Change desc to a string pointer
mysql-test/suite/perfschema/r/all_instances.result:
Added new mutex
mysql-test/suite/perfschema/t/func_mutex.test:
Test for LOCK_system_variables_hash instead of LOCK_grant, as LOCK_grant is not anymore always taken for SELECT's.
mysys/my_gethwaddr.c:
More DBUG
mysys/my_rnd.c:
Change my_rnd() slightly to make it safer if two threads use it at the same time.
sql/event_scheduler.cc:
Changed thread_count to be automically incremented
Moved some safe things out from LOCK_thread_count.
Simplify deleting of THD for running thread.
sql/mysqld.cc:
Changed thread_count to be automically incremented
Thread cache now uses LOCK_thread_cache instead of LOCK_thread_count
Added delete_running_thd()
Moved delete thd out from LOCK_thread_count
More DBUG
Only call mysql_cond_broadcast(&COND_thread_count) if thread_count is 0
Removed call to getsockname() (old not anymore needed check)
sql/mysqld.h:
Removed sql_rnd_with_mutex() (not needed anymore)
Removed not used function get_thread_running()
Added thread_safe_decrement32() and thread_safe_increment32()
Simplified dec_thread_running() and inc_thread_running()
next_query_id() should return the original value for global_query_id, not the next one.
(Bug introduced with MySQL 5.5 merge).
sql/sql_acl.cc:
In check_table_access() don't lock LOCK_grant if we can resolve the grant with user or db level grants (the normal case).
sql/sql_class.cc:
Removed thd_lock_thread_count() and thd_unlock_thread_count()
Initialize random generator without locks
Don't use a lock for setting THD->query_id.
(This is only accessed by thread owning the THD)
sql/sql_class.h:
Don't use a lock for setting THD->query_id.
sql/sql_insert.cc:
Changed thread_count to be automically incremented
sql/sql_parse.cc:
Changed thread_count to be automically incremented
Fixed bug where thd->set_query_id() could be set to same value by multiple threads.
vio/vio.c:
Don't generate 'desc' with sprintf/strmov. Assign a pointer instead.
(Good enough as this is just for debugging)
In some cases, when using views the optimizer incorrectly determined
possible join orders for queries with nested outer and inner joins.
This could lead to invalid execution plans for such queries.
Additional fixes for possible overflows in length-related
calculations in 'spatial' implementations.
Checks added to the ::get_data_size() methods.
max_n_points decreased to occupy less 2G size. An
object of that size is practically inoperable anyway.
Item_func_make_set wasn't taking into account the first argument when
calculating maybe_null.
sql/item_strfunc.cc:
rewrite Item_func_make_set, removing separate storage of the first argument
sql/item_strfunc.h:
rewrite Item_func_make_set, removing separate storage of the first argument
with decimals=NOT_FIXED_DEC it is possible to have 'decimals' larger
than 'max_length', it's not an error for temporal functions.
But when Item_func_numhybrid converts the value to DECIMAL_RESULT,
it must limit 'decimals' to be a valid scale of a decimal number.
STRAIGHT_JOIN couldn't be combined with NATURAL or USING(),
INNER JOIN not with NATURAL (MDEV-4271, MySQL Bug #35268)
Separate rules existed for "natural" (non-outer) joins and
for STRAIGHT_JOIN, with the only difference code wise being
that with STRAIGHT_JOIN the "straight" property of the right
side table was set before calling the appropriate add_...()
function.
The "natural_join" parser rule has now been extended to also
accept STRAIGHT_JOIN, and the rule result value is set to
1 for straight joins, 0 otherwise, so acting as a "straight"
flag that can directly be assigned to the "straight" property
of the right side table.
The rule parsing NATURAL JOIN was hard coded to accept just
this keyword combination, without support for either
STRAIGHT_JOIN or the optional INNER.
The "natural_join" rule has now been split up in an inner
"inner_join" rule that matches the JOIN, INNER JOIN and
STRAIGHT_JOIN cases while "natural_join" also matches
CROSS JOIN.
The NATURAL rule has been changed to accept "inner_join"
instead of just JOIN, so now NATURAL STRAIGHT_JOIN and
NATURAL INNER JOIN also work as expected.
As a side effect the removal of the duplciated rules
for STRAIGHT_JOIN handling has reduced the shift/reduce
conflict count by one.
mysql-test/r/join.result:
Added new test cases
mysql-test/t/join.test:
Added new test cases
sql/sql_yacc.yy:
The "natural_join" parser rule was extended to also accept STRAIGHT_JOIN
NATURAL STRAIGHT_JOIN and NATURAL INNER JOIN also now work as expected
Flip the switch and create Item_cache based on the argument's cmp_type, not argument's result_type().
Fix subselect_engine to calculate cmp_type correctly
sql/item_subselect.h:
mdev:4284
mysql-test/r/keywords.result:
Test that option works as table/column/variable
mysql-test/suite/funcs_1/r/storedproc.result:
OPTION is now a valid identifier
mysql-test/suite/funcs_1/t/storedproc.test:
OPTION is now a valid identifier
mysql-test/t/keywords.test:
Test that option works as table/column/variable
sql/sql_yacc.yy:
OPTION is now a valid identifier
get_datetime_value() should not double-cache its own Item_cache_temporal items,
but it *should* cache other Item_cache items, such as Item_cache_str.
sql/item.h:
shortcut, to avoid going through the switch in Item::cmp_type()
sql/item_cmpfunc.cc:
even if the item is Item_cache_str - it still needs to be converted and cached.
sql/item_timefunc.h:
all descendants of Item_temporal_func always have cmp_type==TIME_RESULT.
Even Item_date_add_interval, that might have field_type == MYSQL_TYPE_STRING.
The bug was found by Alyssa Milburn.
If the number of points of a geometry feature read from
binary representation is greater than 0x10000000, then
the (uint32) (num_points * 16) will cut the higher byte,
which leads to various errors.
Fixed by additional check if (num_points > max_n_points).
This is a bug in the legacy code. It did not manifest itself because
it was masked by other bugs that were fixed by the patches for
mdev-4172 and mdev-4177.
