- 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.
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.
- 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.
The cause of the issue is when DROP DATABASE takes
metadata lock and is in progress through it's
execution, a concurrently running CREATE FUNCTION checks
for the existence of database which it succeeds and then it
waits on the metadata lock. Once DROP DATABASE writes to
BINLOG and finally releases the metadata lock on schema
object, the CREATE FUNCTION waiting on metadata lock
gets in it's code path and succeeds and writes to binlog.
1. Fixing Field_time::get_equal_const_item() to pass TIME_FUZZY_DATES
and TIME_INVALID_DATES to get_time_with_conversion().
This is needed to make the recursively called Item::get_date() return
non-NULL values on garbage input. This makes Field_time::get_equal_const_item()
work consistently with how Item::val_time_packed() works.
2. Fixing Item::get_date() to return TIME'00:00:00' rather than
DATE'0000-00-00' on empty or garbage input when:
- TIME_FUZZY_DATES is enabled
- The caller requested a TIME value (by passing TIME_TIME_ONLY).
This is needed to avoid conversion of DATE'0000-00-00' to TIME
in get_time_with_conversion(), which would erroneously try to subtract
CURRENT_DATE from DATE'0000-00-00' and return TIME'-838:59:59' rather than
the desired zero value TIME'00:00:00'.
#1 and #2 fix these type of scripts to return one row with both
MyISAM and InnoDB, with and without an index on t1.b:
CREATE TABLE t1 (a ENUM('a'), b TIME, c INT, KEY(b));
INSERT INTO t1 VALUES ('','00:00:00',0);
SELECT * FROM t1 WHERE b='';
SELECT * FROM t1 WHERE a=b;
SELECT * FROM t1 IGNORE INDEX(b) WHERE b='';
SELECT * FROM t1 IGNORE INDEX(b) WHERE a=b;
Additionally, #1 and #2 fix the originally reported in MDEV-9604 crash
in Item::save_in_field(), because now execution goes through a different
path, so save_in_field() is called for a Item_time_literal instance
(which is non-NULL) rather than a Item_cache_str instance (which could
return NULL without setting null_value).
3. Fixing Field_temporal::get_equal_const_item_datetime() to enable
equal field propagation for DATETIME and TIMESTAMP in case of
comparison (e.g. when ANY_SUBST), for symmetry with
Field_newdate::get_equal_const_item(). This fixes a number of problems
with empty set returned on comparison to empty/garbage input.
Now all SELECT queries in this script return one row for MyISAM and InnoDB,
with and without an index on t1.b:
CREATE TABLE t1 (a ENUM('a'), b DATETIME, c INT, KEY(b));
INSERT INTO t1 VALUES ('','0000-00-00 00:00:00',0);
SELECT * FROM t1 WHERE b='';
SELECT * FROM t1 WHERE a=b;
SELECT * FROM t1 IGNORE INDEX(b) WHERE b='';
SELECT * FROM t1 IGNORE INDEX(b) WHERE a=b;
Added 5 minute timeout before automaticlally removing threads from thread
cache.
This solves a problem with jemalloc, which is slow with a small
thread cache and also makes thread_cache big enough that most users
doesn't have to touch it
filesort and init_read_record() for the same table.
This will simplify code for WINDOW FUNCTIONS (MDEV-6115)
- Filesort_info renamed to SORT_INFO and moved to filesort.h
- filesort now returns SORT_INFO
- init_read_record() now takes a SORT_INFO parameter.
- unique declaration is moved to uniques.h
- subselect caching of buffers is now more explicit than before
- filesort_buffer is now reusable even if rec_length has changed.
- filsort_free_buffers() and free_io_cache() calls are removed
- Remove one malloc() when using get_addon_fields()
Other things:
- Added --debug-assert-on-not-freed-memory option to make it easier to
debug some not-freed-memory issues.
LOG-SLOW-SLAVE-STATEMENTS NOT DISPLAYED.
These parameters were moved from the command line options to
the system variables section. Treatment of the
opt_log_slow_slave_statements changed to let the
dynamic change of the variable.
