The function Item_direct_view_ref::fix_fields erroneously did not correct
the value of the flag maybe_null when the view for which the item was
being fixed happened to be an inner table of an outer join.
Honor unique/not unique when creating keys for internal tempory tables.
Added new variables to be used to limit how keys are created for internal temporary tables.
include/maria.h:
Added maria_max_key_length() and maria_max_key_segments()
include/myisam.h:
Added myisam_max_key_length() and myisam_max_key_segments()
mysql-test/r/mysql.result:
Drop all used tables
mysql-test/r/subselect4.result:
Added test case for lp:879939
mysql-test/t/mysql.test:
Drop all used tables
mysql-test/t/subselect4.test:
Added test case for lp:879939
sql/mysql_priv.h:
Added internal_tmp_table_max_key_length and internal_tmp_table_max_key_segments to be used to limit how keys for derived tables are created.
sql/mysqld.cc:
Added internal_tmp_table_max_key_length and internal_tmp_table_max_key_segments to be used to limit how keys for derived tables are created.
sql/share/errmsg.txt:
Added new error message for internal errors
sql/sql_select.cc:
Give error if we try to create a wrong key (this error should never happen)
Honor unique/not unique when creating keys for internal tempory tables.
storage/maria/ha_maria.cc:
Added change_table_ptr() to ensure that external_ref points always to the correct table.
(Not having this caused an assert in the included test)
storage/maria/ha_maria.h:
Added change_table_ptr() to ensure that external_ref points always to the correct table.
storage/maria/ma_check.c:
Fixed bug in Duplicate key error printing (now row position is printed correctly)
storage/maria/ma_create.c:
maria_max_key_length() -> _ma_max_key_length()
storage/maria/ma_info.c:
Added extern function maria_max_key_length() to calculate the max key length based on current block size.
storage/maria/ma_open.c:
maria_max_key_length() -> _ma_max_key_length()
storage/maria/maria_def.h:
maria_max_key_length() -> _ma_max_key_length()
storage/myisam/ha_myisam.cc:
Added change_table_ptr() to ensure that external_ref points always to the correct table.
(Not having this caused an assert in the included test)
storage/myisam/ha_myisam.h:
Added change_table_ptr() to ensure that external_ref points always to the correct table.
The function SELECT_LEX::update_used_tables first must clean up
all bitmaps to be recalculated for all tables that require it
and only after this walk through on conditions attached to the
tables to update these bitmaps.
- when create_ref_for_key() is constructing a ref access for
a table that's inside a SJ-Materialization nest, it may not
use references to fields of tables that are unside the nest (because
these fields will not yet have values when ref access will be used)
The check was performed in the first of create_ref_for_key's loops (the
one which counts how many key parts are usable) but not in the second
(the one which actually fills the TABLE_REF structure).
If a materialized derived table / view is empty then for this table
the value of file->ref is 0. This was not taken into account by
the function JOIN_CACHE::write_record_data. As a result a query
using an empty materialized derived tables as inner tables of outer
joins and IN subqueries in WHERE conditions could cause server crashes
when the optimizer employed join caches and duplicate elimination for
semi-joins.
This bug happened for the queries over multi-table mergeable views
because the bitmap TABLE::read_set of the underlying tables were not
updated after the views had been merged into the query.
Now this bitmaps are updated properly.
Also the bitmap TABLE::merge_keys now is updated in prevention of
future bugs.
The function JOIN::drop_unused_derived_keys could erroneously set
the value of REF::key to 0 for a joined materialized view/derived table
in the case when no REF access to the table was used by the query
execution plan. This could cause a crash of the server.
This bug happened due to incompleteness of the fix for bug 872735:
the occurrences of the fields in the conditions of correlated
subqueries were not taken into account when recalculating
covering keys bit maps.
This bug manifested itself with queries containing non-correlated
IN subqueries over materialized views/derived tables.
The bug happened because the code of the function generate_derived_keys did
not take into account that the function could be called twice when the
optimizer was deciding whether in-exist transformation should be applied.
This bug happened because the maps of covering keys for mergeable derived
tables/views was not recalculated after the derived tables/vies had been
merged into the main query.
- in make_join_select(), use the correct condition to check whether the current table is a SJM nest (the previous
condition used to be correct before, but then sj-materialization temp table creation was moved to happen before
make_join_select was called)
This bug is a consequence of the fix in the function add_ref_to_table_cond
for LP bug 826935 that turned out to be not quite correct: it tried to AND
the same generated condition with two different other conditions.
This patch creates a copy of the generated condition if the condition needs
to be ANDed with two different items.
Cleanup: Changed procedure type from a int/char to an enum for easier to manage and debug code.
mysql-test/r/trigger.result:
Test that mysql.proc is not used as part of creating or using a trigger.
mysql-test/t/trigger.test:
Test that mysql.proc is not used as part of creating or using a trigger.
sql/sp.cc:
The main bug fix is to not look up triggers in mysql.proc; This is done by ignoreing type == TYPE_ENUM_TRIGGER in sp_add_used_routine()
Cleanup: Changed procedure type from a int/char to an enum.
sql/sp.h:
Cleanup: Changed procedure type from a int/char to an enum.
sql/sp_head.h:
Cleanup: Changed procedure type from a int/char to an enum.
sql/sql_db.cc:
Fix include order
sql/sql_lex.cc:
Fix include order
sql/sql_parse.cc:
Cleanup: Changed procedure type from a int/char to an enum.
sql/sql_show.cc:
Fix include order
sql/sql_view.cc:
Fix include order
Analysis:
The cause of the bug was that the method
subselect_rowid_merge_engine::partial_match()
was not designed for re-execution within the
same query. Specifically, it didn't cleanup
the bitmap of matching keys after completion.
The test query requires double execution of
the IN predicate because it first checks the
predicate as a constant condition. The second
execution during regular execution used the bitmap
of matching keys produced by the first execution
instead of starting with a clean one.
Solution:
Cleanup the bitmap of matching keys at the end of
the partial matching procedure.
bugfix: garbage in PLUGIN_VAR_STR variables when INSTALL'ing a plugin
mysql-test/include/default_mysqld.cnf:
disable feedback plugin by default.
when enabled - tag is as a test run
Analysis:
The cause of the bug was the changed meaning of
subselect_partial_match_engine::has_covering_null_row.
Previously it meant that there is row with NULLs in
all nullable fields of the materialized subquery table.
Later it was changed to mean a row with NULLs in all
fields of this table.
At the same time there was a shortcut in
subselect_rowid_merge_engine::partial_match() that
detected a special case where:
- there is no match in any of the columns with NULLs, and
- there is no NULL-only row that covers all columns with
NULLs.
With the change in the meaning of has_covering_null_row,
the condition that detected this special case was incomplete.
This resulted in an incorrect FALSE, when the result was a
partial match.
Solution:
Expand the condition that detected the special case with the
correct test for the existence of a row with NULL values in
all columns that contain NULLs (a kind of parially covering
NULL-row).
of the 5.3 code line after a merge with 5.2 on 2010-10-28
in order not to allow the cost to access a joined table to be equal
to 0 ever.
Expanded data sets for many test cases to get the same execution plans
as before.
- convert_subq_to_jtbm() didn't check that subuqery optimization was successful. If it wasn't (in this
example because of @@max_join_size violation), it would proceed further and eventually crash when
trying to execute the un-optimized subquery.
- The problem was that JOIN::save/restore_query_plan() did not save/restore parts of
the query plan that are located inside SJ_MATERIALIZATION_INFO structures. This could
cause parts of one plan to be used with another, which led get_best_combination() to
constructing non-sensical join plans (and crash).
Fixed by saving/restoring SJM parts of the query plans.
- check_and_do_in_subquery_rewrites() will not set SUBS_MATERIALIZATION flag when it
records that the subquery predicate is to be converted into semi-join.
If convert_join_subqueries_to_semijoins() later decides not to convert to semi-join,
let it set SUBS_MATERIALIZATION flag, if appropriate.
- are_tables_local() failed to recognize the fact that OUTER_REF_TABLE_BIT is ok
for SJ-Materialization. This caused zero-length ref access to be constructed, which
led to an assert.
Analysis:
The crash is a result of the same cause as all similar
bugs (lp:827416, lp:718763, lp:778413, lp:806943,
lp:611690). The general pattern is that some optimization
requires the evaluation of some condition (e.g. the WHERE
clause), and this condition contains a subquery, such that
the subquery itself requires a temporary table for its
execution. During the subquery execution the original
tables in the FROM clause are replaced by the temporary
table needed for the final GROUP or ORDER operation. All
this happens during optimization of the outer query. Later
when EXPLAIN is run for the subquery, explain attempts to
print the name of the tables in the FROM clause, but it
finds there a temporary table without a corresponding
TABLE_LIST object. The attempt to print the name of a
NULL table list results in a crash.
Solution:
This patch extends the fix to bug lp:702301, and dissalows
constant substitution of aggregate functions if the filter
condition used to check MIN/MAX keys is an expensive condition.
