mysql-test/r/subselect4.result:
Moved test case for LP BUG#718593 into the correct test file subselect_mat_cost_bugs.test.
mysql-test/t/subselect4.test:
Moved test case for LP BUG#718593 into the correct test file subselect_mat_cost_bugs.test.
- in advance_sj_state(), remember join->cur_dups_producing_tables in
pos->prefix_dups_producing_tables *before* we modify it, so that
restore_prev_sj_state() restores cur_dups_producing_tables in all cases.
- Updated test results in subselect_sj2[_jcl6].result (the original EXPLAIN
was invalid there)
Resolved all conflicts, bad merges and fixed a few minor bugs in the code.
Commented out the queries from multi_update, view, subselect_sj, func_str,
derived_view, view_grant that failed either with crashes in ps-protocol or
with wrong results.
The failures are clear indications of some bugs in the code and these bugs
are to be fixed.
sql/item_subselect.cc:
Cleanup. Comments added.
sql/item_subselect.h:
Cleanup.
sql/mysql_priv.h:
Comments added.
sql/opt_subselect.cc:
The function renamed and turned to method.
Comments added.
sql/opt_subselect.h:
The function turned to method of JOIN.
sql/sql_select.cc:
Comment added. The function turned to method.
sql/sql_select.h:
The function turned to method.
mysql-test/r/explain.result:
fixed results (new item)
mysql-test/r/subselect.result:
fixed results (new item)
mysql-test/r/subselect_no_mat.result:
fixed results (new item)
mysql-test/r/subselect_no_opts.result:
fixed results (new item)
mysql-test/r/subselect_no_semijoin.result:
Fixed results (new item)
mysql-test/suite/pbxt/r/subselect.result:
Fixed results (new item)
mysql-test/t/explain.test:
Fixed results (correct behaviour)
sql/item_cmpfunc.cc:
Pass through for max/min
sql/item_subselect.cc:
moving max/min
sql/item_subselect.h:
moving max/min
sql/mysql_priv.h:
new uncacheble flags added
sql/opt_subselect.cc:
maxmin moved.
sql/opt_subselect.h:
New function for maxmin.
sql/sql_class.h:
debug code
sql/sql_lex.cc:
Fixed flags.
Limit setting fixed.
sql/sql_lex.h:
2 new flags.
sql/sql_select.cc:
Prepare divided on 2 function to be able recollect some info after transformation.
sql/sql_select.h:
Prepare divided on 2 functions.
Both these two bugs happened due to the following problem.
When a view column is referenced in the query an Item_direct_view_ref
object is created that is refers to the Item_field for the column.
All references to the same view column refer to the same Item_field.
Different references can belong to different AND/OR levels and,
as a result, can be included in different Item_equal object.
These Item_equal objects may include different constant objects.
If these constant objects are substituted for the Item_field created
for a view column we have a conflict situation when the second
substitution annuls the first substitution. This leads to
wrong result sets returned by the query. Bug #724942 demonstrates
such an erroneous behaviour.
Test case of the bug #717577 produces wrong result sets because best
equal fields of the multiple equalities built for different OR levels
of the WHERE condition differs. The subsitution for the best equal field
in the second OR branch overwrites the the substitution made for the
first branch.
To avoid such conflicts we have to substitute for the references
to the view columns rather than for the underlying field items.
To make such substitutions possible we have to include into
multiple equalities references to view columns rather than
field items created for such columns.
This patch modifies the Item_equal class to include references
to view columns into multiple equality objects. It also performs
a clean up of the class methods and adds more comments. The methods
of the Item_direct_view_ref class that assist substitutions for
references to view columns has been also added by this patch.
- Let advance_sj_state() save the value of JOIN::cur_dups_producing_tables
in POSITION::prefix_dups_producing_tables, and restore_sj_state() restore
it.
The patch also adjusts several instable test results
to order the result.
Analysis:
The function prev_record_reads() may skip (jump over)
some query plan nodes where record_count < 1. At the
same time, even though get_partial_join_cost() uses
all first N plan nodes after the last constant table,
it may produce a smaller record_count than
prev_record_reads(), because the record count for
some plan nodes may be < 1, and these nodes may not
participate in prev_record_reads.
Solution:
The current solution is to treat the result of
get_partial_join_cost() as the upper bound for the
total number of unique lookup keys.
Fixed LP BUG#714808 Assertion `outer_lookup_keys <= outer_record_count'
Analysis:
The function best_access_path() computes the number or records as
follows:
...
if (rec < MATCHING_ROWS_IN_OTHER_TABLE)
rec= MATCHING_ROWS_IN_OTHER_TABLE; // Fix for small tables
...
if (table->quick_keys.is_set(key))
records= (double) table->quick_rows[key];
else
{
/* quick_range couldn't use key! */
records= (double) s->records/rec;
}
Above MATCHING_ROWS_IN_OTHER_TABLE == 10, and s->records == 1,
thus we get an estimated 0.1 records. As a result JOIN::get_partial_join_cost()
for the outer query computes outer_record_count == 0.1 records, which is
meaningless in this context.
Solution:
Round row count estimates that are < 1 to 1.
- fixed incorrect query plans that resulted from emptying the
keyuse array with the access methods of the non-modified query
plan.
- fixed compiler warning.
Aria and MyISAM in create_internal_tmp_table_from_heap()
(safe, as duplicates are impossible).
This gives a HUGE speed boost!
sql/opt_subselect.cc:
Fixed problem with wrong recinfo in create_duplicate_weedout_tmp_tabl()
Tagged the table with 'no_rows' so that when we create the table on disk,
we only store the index data. This gave us a major speedup!
sql/sql_select.cc:
create_tmp_table_from_heap() now uses bulk_insert + repair_by_sort
when creating Aria/MyISAM tables from HEAP tables.
This gives a HUGE speed boost!
storage/maria/ha_maria.cc:
Extended bulk_insert() to recreate UNIQUE keys for
internal temporary tables
storage/maria/ma_open.c:
Initialize m_info->lock.type properly for temporarly tables
(needed for start_bulk_insert())
storage/maria/ma_write.c:
Don't check uniques that are disabled
storage/myisam/ha_myisam.cc:
Extended bulk_insert() to recreate UNIQUE keys for
internal temporary tables.
This will also enable us in the future to collect statistics for
writes to internal tmp tables.
sql/handler.h:
Added ha_write_tmp_row()
sql/opt_subselect.cc:
ha_write_row -> ha_write_tmp_row
sql/sql_class.h:
Added ha_write_tmp_row()
sql/sql_select.cc:
ha_write_row -> ha_write_tmp_row
