- Let index_merge allocate table handlers on quick select's MEM_ROOT,
not on statement's MEM_ROOT.
This is crucial for big "range checked for each record" queries, where
index_merge can be created and deleted many times during query exection.
We should not make O(#rows) allocations on statement's MEM_ROOT.
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.
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.
The reason is the limitation of ReadConsole() API, it returns error if handle to redirected input is used.
The fix is to use a handle returned by CreateFile("CONIN$",...), rather than GetStdHandle(STD_HANDLE_INPUT) to get the true console handle.
The output of mysqlbinlog (with "-v --base64-output=DECODE-ROWS" flags) can not always be read or parsed correctly
when string columns contain single-quotes or backslash characters.
The fix for this bug is to escape single-quote and backslash characters on output, so that the result is both more
readable and more easily parse-able.
Note that this is just for comments, so it doesn't affect the replication.
sql/log_event.cc:
Escape \ and ' properly for mysqlbin user comments.
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.
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 reason for the problem was negation of signed longlong value LONGLON
G_MIN in Item_func_neg::int_op() - the result of this operation is not defined
(in C/C++ standard).
With this patch, LONGLONG_MIN is handled as special value, and negation is
avoided.
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.
