Problem: When building the condition for JOIN::outer_ref_cond the optimizer forgot to take into account
that this condition could depend on constant tables as well.
mysql-test/r/information_schema_all_engines.result:
Update result
mysql-test/t/information_schema_all_engines.test:
Added --sorted-results as tables in information_schema are not sorted.
- Create/use do_copy_nullable_row_to_notnull() function for ref access, which is used
when copying from not-NULL field in table that can be NULL-complemented to not-NULL field.
- ensure that mtr supressions table is flushed before doing controlled crash and restart
- use DBUG_SUICIDE() rather than abort() in partition tests - avoids a crash message/warning
- disable perfschema all_instances test on Windows- there are legitimate reasons for output to be different on Unix (some different threads, some different locks), the differences are expected to grow in the future, e.g with threadpool.
from a heap temptable, which uses pointers to records (that is, byte*
pointers) as rowids.
This meant that for rows with the same sort key value, the order
was determined by memory layout.
fixed several defects in the greedy optimization:
1) The greedy optimizer calculated the 'compare-cost' (CPU-cost)
for iterating over the partial plan result at each level in
the query plan as 'record_count / (double) TIME_FOR_COMPARE'
This cost was only used locally for 'best' calculation at each
level, and *not* accumulated into the total cost for the query plan.
This fix added the 'CPU-cost' of processing 'current_record_count'
records at each level to 'current_read_time' *before* it is used as
'accumulated cost' argument to recursive
best_extension_by_limited_search() calls. This ensured that the
cost of a huge join-fanout early in the QEP was correctly
reflected in the cost of the final QEP.
To get identical cost for a 'best' optimized query and a
straight_join with the same join order, the same change was also
applied to optimize_straight_join() and get_partial_join_cost()
2) Furthermore to get equal cost for 'best' optimized query and a
straight_join the new code substrcated the same '0.001' in
optimize_straight_join() as it had been already done in
best_extension_by_limited_search()
3) When best_extension_by_limited_search() aggregated the 'best' plan a
plan was 'best' by the check :
'if ((search_depth == 1) || (current_read_time < join->best_read))'
The term '(search_depth == 1' incorrectly caused a new best plan to be
collected whenever the specified 'search_depth' was reached - even if
this partial query plan was more expensive than what we had already
found.
The patch differs from the original MySQL patch as follows:
- All test case differences have been reviewed one by one, and
care has been taken to restore the original plan so that each
test case executes the code path it was designed for.
- A bug was found and fixed in MariaDB 5.3 in
Item_allany_subselect::cleanup().
- ORDER BY is not removed because we are unsure of all effects,
and it would prevent enabling ORDER BY ... LIMIT subqueries.
- ref_pointer_array.m_size is not adjusted because we don't do
array bounds checking, and because it looks risky.
Original comment by Jorgen Loland:
-------------------------------------------------------------
WL#5953 - Optimize away useless subquery clauses
For IN/ALL/ANY/SOME/EXISTS subqueries, the following clauses are
meaningless:
* ORDER BY (since we don't support LIMIT in these subqueries)
* DISTINCT
* GROUP BY if there is no HAVING clause and no aggregate
functions
This WL detects and optimizes away these useless parts of the
query during JOIN::prepare()
- The problem was that const-table-reading code would try to evaluate MATCH()
before init_ftfuncs() was called.
- Fixed by making MATCH function "expensive" so that nobody tries to evaluate it
at optimization phase.
Failures on SUN Solaris. Buggy compiler there required some extra initialization
for variables. Then the 02 optimization leads to bugs when values set through the
pointer are not always taken into account. Finally, the (long long) / (long)
crashes there, the explicit typeconverstion added.
Failing innodb_plunin.innodb_gis.test fixed.
per-file comments:
mysql-test/suite/innodb_plugin/t/innodb_gis.test
GIS issues fixed.
sql/gcalc_slicescan.cc
GIS issues fixed.
sql/gcalc_tools.cc
GIS issues fixed.
- Correctly handle plan refinement stage for LooseScan plans: run create_ref_for_key() if LooseScan
plan includes a ref access, and if we don't have any fixed key components, switch to a full index scan.
Fix typo causing too low timeout value for wait_for_slave_param.inc.
Fix binlog checksums following 5.5 merge.
Make sure the rpl suite can run with --mysqld=--binlog-checksum=CRC32
Fix a number of problems in the code when checksums are enabled.
- Let JTBM optimization code handle the case where the subquery is degenerate and doesn't have a
join query plan. Regular materialization would fall back to IN->EXISTS for such cases. Semi-Join
materialization does not have such option, instead we introduce and use "constant JTBM join tabs".
