- Avoid some realloc() during startup
- Ensure that file_key_management_plugin frees it's memory early, even if
it's linked statically.
- Fixed compiler warnings from unused variables and missing destructors
- Fixed wrong indentation
Make Frame_range_current_row_bottom to take into account partition bounds.
Other partition bounds that could potentially hit the end of partition are
Frame_range_n_bottom, Frame_n_rows_following, Frame_unbounded_following,
and they all had end-of-partition protection.
To simplify the code, factored out end-of-partition checks into
class Partition_read_cursor.
This bug revealed a serious problem: if the same partition list
was used in two window specifications then the temporary table created
to calculate window functions contained fields for two identical
partitions. This problem was fixed as well.
n=0 in "ROWS 0 PRECEDING" is valid, add handling for it:
- Adjust the assert
- Bottom bound of 'ROW 0 PRECEDING' is actually looking at the current
row, that is, it needs to process partition's first row directly in
Frame_n_rows_preceding::next_partition().
- Added testcases
" The sort order for the sub-sequence of window functions starting
from the element marked by SORTORDER_CHANGE_FLAG up to the next
element marked by SORTORDER_CHANGE_FLAG must be taken from the
last element of the sub-sequence (not from the first one)."
- Rename Window_funcs_computation to Window_funcs_computation_step
- Introduce Window_func_sort which invokes filesort and then
invokes computation of all window functions that use this ordering.
- Expose Window functions' sort operations in EXPLAIN|ANALYZE FORMAT=JSON
that the call-back comparison function returns a positive
number when arg1 < arg2, and a negative number when arg1 > arg2.
This is not in line with other implementation of sorting
algorithm.
Changed bubble_sort: now a negative result from the comparison
function means that arg1 < arg2, and positive result means
that arg1 > arg2.
Changed accordingly all call-back functions that are used as
parameters in the call of bubble_sort.
Added a test case to check the proper sorting of window functions.
- Hook window function computation into the right location.
- Add a testcase which shows that HAVING is now checked before
the window function computation step.
We can call setup_partition_border_check() from
JOIN::make_aggr_tables_info(), provided that call is made after
appropriate set_items_ref_array() call.
Added class Window_funcs_computation, with setup() method to setup
execution, and exec() to run window function computation.
setup() is currently trivial. In the future, it is expected to optimize
the number of sorting operations and passes that are done over the temp.
table.
- Make Item_XXX::cleanup() clean List<Cached_item> orderby_fields.
(Items survive across PS re-executions. Cached_item don't, because
they keep pointers to fix_field'ed items, etc)
- Move List<Cached_item> out into Group_bound_tracker.
Item_func_or_sum.
Implemented method update_used_tables for class Item_findow_func.
Added the flag Item::with_window_func.
Made sure that window functions could be used only in SELECT list
and ORDER BY clause.
Added test cases that checked different illegal placements of
window functions.
with window functions. Added the test case for it.
Also allowed to use aliases for set functions in partition and order lists
that are specified in window functions.
of the type SQL_I_List<ORDER> rather then the objects of this type.
It allows to replace easily one instance of such a list for another.
Besides it will facilitate to compare two lists if they originate from the
same window specification.
In fact any direct assignment for objects of the type SQL_I_List<ORDER>
was not valid.
It is based on the sum() function, thus much of the logic is shared.
Considering that there are 2 counters stored within the function, one
that handles the null value, while the other that handles the divisor
for the avg computation, it is possible to remove the counter from the
Item_sum_avg. I have not removed it in this patch as we may choose to
refactor the whole code into a separate class.
This remains to be dicussed.
The counter keeps track of the number of items added to the sum
function. It is increased when we add a value to the sum function and
decreased when it is removed.
Add support for "RANGE n PRECEDING|FOLLOWING" frame bounds.
- n is currently limited to whatever Item and Item_sum_plus/minus
can handle (i.e. no DATETIME intervals).
- Didn't check NULL value handling yet.
Part#2: Fix a couple more issues in rows-type frames.
This also has a code cleanup:
- introduce a separate Frame_rows_current_row_(top,bottom). This is
is a special case which doesn't need its cursor or partition bound check
- Split Frame_n_rows into
= Frame_n_rows_preceding (this one is now much simpler)
= Frame_n_rows_following (simpler and works but may need some work still)
Part#1: Frame_n_rows::next_partition() should not assume that the
current table->record[0] points to the first row in the partition.
Since cursor supports move_to() operation, we dont need this.
