The patch to fix mdev-4418 turned out to be incorrect.
At the substitution of single row tables in make_join_statistics()
the used multiple equalities may change and references to the new multiple
equalities must be updated. The function remove_eq_conds() takes care of it and
it should be called right after the substitution of single row tables.
Calling it after the call of make_join_statistics was a mistake.
Analysis:
The cause of the valgrind warning was an attempt to evaluate a Field that was not yet read.
The reason was that on one hand Item_func_isnotnull was marked as constant by
Item_func_isnotnull::update_used_tables, and this allowed eval_const_cond() to be called.
On the other hand Item_func_isnotnull::val_int() evaluated its argument as if it was not
constant.
Solution:
The fix make sure that Item_func_isnotnull::val_int() doesn't evaluate its argument when
it is constant and cannot be NULL, because the result is known in this case.
After single row substitutions there might appear new equalities.
They should be properly propagated to all AND/OR levels the WHERE
condition. It's done now with an additional call of remove_eq_conds().
This patch almost totally revised the patch for bug mdev-4177.
The latter had too many defects. In particular, it did not
propagate multiple equalities formed when merging a degenerate
disjunct into underlying AND formula.
This a an old legacy performance bug.
When a very selective range scan existed for the second table in a join,
and, at the same time, there was another range condition depending on the
fields of the first table, the optimizer chose a plan with
'Range checked for each record'. This plan was extremely inefficient in
comparison with the regular selective range scan.
As a matter of fact the range scan chosen for each record was the same as
that selective range scan.
Changed the test case for bug 24776 to preserve the old output for explain.
MDEV-4812 Valgrind warnings (Invalid write) in dynamic_column_update_many on COLUMN_ADD
Fixed problem of working on wrong data (do not allow offset to out of string length).
fix_field() call protocol was brocken (zero pointer passed as link to item which is possible only if you are sure that there can not be Items which transforms).
If there is a key cache resize,a thread writing to key cache, will pause waiting until resize finishes. However this thread is won't be woken, because resize does not signaling waiters anymore. This is a regression introduced in WL#86(segmented MyISAM key cache)
The fix is to unconditionally release threads waiting on resize_queue when resize finishes, as in pre-WL#86 code.
MDEV-4643 MariaDB crashes consistently when trying a SELECT on VIEW with a UNION and an additional JOIN in SELECT
open derived temp tables *before* trying QUICK_SELECT for them,
handler::multi_range_read_info() needs an open table.
Cleanup: remove TIME_FUZZY_DATE.
Introduce TIME_FUZZY_DATES which means "very fuzzy, the resulting
value is only used for comparison. It can be invalid date, fine, as long as it can be
compared".
Updated many tests results (they're better now).
Item_func_min_max::get_date() did not check the
returned value against the fuzzy_date flags, so
it could return a bad value to the caller that
expects a good date (e.h. CONVERT_TZ).
modified:
mysql-test/r/type_date.result
mysql-test/r/type_datetime.result
mysql-test/r/type_time.result
mysql-test/t/type_date.test
mysql-test/t/type_datetime.test
mysql-test/t/type_time.test
sql/item_func.cc
sql/item_timefunc.cc
sql/mysql_priv.h
sql/time.cc
mysql_derived_merge_for_insert() should not be called for views or derived tables which are not put (directly or via other views) in main SELECT_LEX "join list".
This could happen when using Aria for internal temporary files (default case) and using DISTINCT.
_ma_scan_restore_block_record() didn't work correctly if there was rows inserted, updated or deleted on the handler
between calls to _ma_scan_remember_block_record() and _ma_scan_restore_block_record().
The effect was that some DISTINCT queries that used remove_dup_with_compare() could fail.
.bzrignore:
Ignore sql_yacc.hh
mysql-test/suite/maria/r/distinct.result:
Test case for MDEV-4280
mysql-test/suite/maria/t/distinct.test:
Test case for MDEV-4280
mysql-test/t/mysql.test:
Fixed test suite (we could get error -1 in some cases)
sql/sql_select.cc:
Break loop if restart_rnd_next() gives an error
storage/maria/ha_maria.cc:
scan_restore_pos() can return disk fault error.
storage/maria/ma_blockrec.c:
_ma_scan_remember_block_record() did incorrectly update scan.dir instead of scan_save.dir .
_ma_scan_restore_block_record() didn't work correctly if there was rows inserted,updated or deleted on the handler
between calls to _ma_scan_remember_block_record() and _ma_scan_restore_block_record().
Fixed by adding counters for row changes and reading the current scan page if changes had been made.
storage/maria/ma_blockrec.h:
scan_restore_pos() can return disk fault error.
storage/maria/ma_delete.c:
Increment row_changes
storage/maria/ma_scan.c:
scan_restore_pos() can return disk fault error.
storage/maria/ma_update.c:
Increment row_changes
storage/maria/ma_write.c:
Increment row_changes
storage/maria/maria_def.h:
scan_restore_pos() can return disk fault error.
When iterating over a list of conditions using List_iterator
the function remove_eq_conds should skip all predicates that
replace a condition from the list. Otherwise it can come to
an infinite recursion.
<non-nullable datatime field> IS NULL in outer joins with
that in inner joins.
Previously such condition was transformed into the condition
<non-nullable datatime field> = 0 unless the field belonged
to an inner table of an outer join. In this case the predicate
was interpreted as for any other field.
Now if the field in the predicate <non-nullable datatime field> IS NULL
belongs to an inner table of an outer join the predicate is
transformed into the disjunction
<non-nullable datatime field> = 0 OR <non-nullable datatime field> IS NULL.
This is fully compatible with the semantics of such predicates in 5.5.
This bug was the result of incompleteness of the patch for bug mdev-4177.
When an OR condition is simplified to a single conjunct it is merged
into the embedding AND condition. Multiple equalities are also merged,
and any field item involved in those equality should acquire a pointer
to a the multiple equality formed by this merge.
