The function Item::split_sum_func2() incorrectly processed the function
items with window functions that were not window functions themselfes
and were used as arguments of other functions.
The function st_select_lex_unit::exec_recursive() incorrectly determined
that a CTE mutually recursive with some others was stabilized in the case
when the non-recursive part of the CTE returned an empty set. As a result
the server fell into an infinite loop when executing a query using
this CTE.
Mutually recursive CTE could cause a crash of the server in the case
when they were not Standard compliant. The crash happened in
mysql_derived_prepare(), because the destructor the derived_result
object created for a CTE that was mutually recursive with some others
was called twice. Yet this destructor should not be called for resursive
references.
The method With_element::check_unrestricted_recursive() icorrectly performed
the check that no recursive reference is not encountered in inner parts of
outer joins. As a result the server reported errors for valid specifications
with outer joins.
In get_mm_tree we have to change Field_geom::geom_type to
GEOMETRY as we have to let storing all types of the spatial features
in the field. So now we restore the original geom_type as it's
done.
character (").
The my_wildcmp function doesn't expect the string parameter to
have escapements, only the template. So the string
should be unescaped if necessary.
The bug was caused by a wrong order of statements in With_clause::print().
As a result any view definition containing WITH clause with several
CTE specifications was put the frm file in a syntactically incorrect
form.
The issue was that JOIN::rollup_write_data() used
JOIN::tmp_table_param::[start_]recinfo, which had uninitialized data.
These fields have uninitialized data, because JOIN::tmp_table_param
currently only stores some grouping-related data fields. The data about
the work (temporary) tables themselves is stored in
join->join_tab[...].tmp_table_param.
The fix is to make JOIN::rollup_write_data follow this convention
and look at the right TMP_TABLE_PARAM object
The bug was not visible in current HEAD. Introduced test case to catch
regressions. Also improve error messages regarding distinct usage in
window functions.
The bug was caused by several issues.
2 problems in seek_io_cache. Due to wrong offsets used, we would end up
seeking way too much (first change), or over the intended seek point
(second change). Fixing it requires correctly detecting available data
in buffer (first change), and not using "IO_SIZE alligned" reads. The
second is needed because _my_b_cache_read adjusts the pos_in_file itself
based on read_pos and read_end. Pretending buffer is empty when we want
to force a read will aleviate this problem.
Secondly, the big-table cursors didn't repect the interface definitions
of always returning the rownumber that Table_read_cursor::fetch() would activate.
At the same time, next(), prev() and move_to() should not perform any
row activation.
Window functions need to be computed after applying the HAVING clause.
An optimization that we have for regular, non-window function, cases is
to apply having only during sending of the rows to the client. This
allows rows that should be filtered from the temporary table used to
store aggregation results to be stored there.
This behaviour is undesireable for window functions, as we have to
compute window functions on the result-set after HAVING is applied.
Storing extra rows in the table leads to wrong values as the frame
bounds might capture those -to be filtered afterwards- rows.
PART 2 of the fix adds the logic of not using password column, unless it
exists. If password column is missing we attempt to use plugin &&
authentication_string columns.
The same approach is needed for LAST_VALUE, otherwise the LAST_VALUE sum
functions are not cleared correctly. Now LAST_VALUE behaves as NTH_VALUE
with 0 offset, only that the frame that it is examining is the bottom bound,
not the top bound.
The problematic queries involve unions. For unions we have an
optimization where we skip the ORDER BY clause in a query from one side
of the union if it will be performed later due to UNION.
EX:
(SELECT a from t1 ORDER BY a) ORDER BY b;
The first ordering by a is not necessary and it gets removed.
The problem is that we still need to resolve the Items before removing the
ORDER BY list from the
SELECT_LEX structure. During this final resolve step however, we forgot to
allow SET functions within the ORDER BY clause. This caused us to return
an "Invalid use of group function" error during the checking performed
by fix_fields in Item_sum::init_sum_func_check.
change the parser not to allow SERIAL as a normal data type.
make a special rule for it, where it could be used for define
fields, but not generated fields, not return type of a stored function, etc.
JOIN_CACHE's were initialized in check_join_cache_usage()
from make_join_readinfo(). After that make_join_readinfo() was looking
whether it's possible to use keyread. Later, after make_join_readinfo(),
optimizer decided whether to use filesort. And even later, at the
execution time, from join_read_first(), keyread was actually enabled.
The problem is, that if a query uses a vcol, base columns that it
depends on are automatically added to the read_set - because they're
needed to calculate the vcol. But if we're doing keyread, vcol is taken
from the index, not calculated, and base columns do not need to be
in the read set (even should not be - as they aren't getting values).
The bug was that JOIN_CACHE used read_set with base columns,
they were not read because of keyread, so it was caching garbage.
So read_set is only known after the keyread was decided. And after the
filesort was decided, as filesort doesn't use keyread. But
check_join_cache_usage() needs to be done in make_join_readinfo(),
as the code below depends on these checks,
Fix: keep JOIN_CACHE checks where they were, but move initialization
down to the very end of JOIN::optimize_inner. If keyread was enabled,
update the read_set to include only columns that are part of the index.
Copy the keyread logic from join_read_first() to happen at optimize time.
Optionally do table->update_default_fields() even for INSERT
that supposedly provides values for all column. Because these
"values" might be DEFAULT, which would need table->update_default_fields()
at the end.
Also set Item_default_value::used_tables() from the default expression.
Non-zero used_field() means that mysql_insert() will initialize all
fields to their default values (with restore_record()) even if
all columns are later provided with values. Because default expressions
may refer to other columns and they must be initialized.
These are different bugs, but the fixing code is the same:
if window functions are used over implicit grouping then
now the execution should follow the general path calling
the function set in JOIN::first_select.
