revno: 2876.47.174
revision-id: jorgen.loland@oracle.com-20110519120355-qn7eprkad9jqwu5j
parent: mayank.prasad@oracle.com-20110518143645-bdxv4udzrmqsjmhq
committer: Jorgen Loland <jorgen.loland@oracle.com>
branch nick: mysql-trunk-11765831
timestamp: Thu 2011-05-19 14:03:55 +0200
message:
  BUG#11765831: 'RANGE ACCESS' MAY INCORRECTLY FILTER 
                        AWAY QUALIFYING ROWS
        
  The problem was that the ranges created when OR'ing two 
  conditions could be incorrect. Without the bugfix, 
  "I <> 6 OR (I <> 8 AND J = 5)" would create these ranges:
  
  "NULL < I < 6",
  "6 <= I <= 6 AND 5 <= J <= 5",
  "6 < I < 8",
  "8 <= I <= 8 AND 5 <= J <= 5",
  "8 < I"
  
  While the correct ranges is
  "NULL < I < 6",
  "6 <= I <= 6 AND 5 <= J <= 5",
  "6 < I"
  
  The problem occurs when key_or() ORs
  (1) "NULL < I < 6, 6 <= I <= 6 AND 5 <= J <= 5, 6 < I" with 
  (2) "8 < I AND 5 <= J <= 5"
  
  The reason for the bug is that in key_or(), SEL_ARG *tmp is 
  used to point to the range in (1) above that is merged with 
  (2) while key1 points to the root of the red-black tree of 
  (1). When merging (1) and (2), tmp refers to the "6 < I" 
  part whereas the root is the "6 <= ... AND 5 <= J <= 5" part. 
  
  key_or() decides that the tmp range needs to be split into
  "6 < I < 8, 8 <= I <= 8, 8 < I", in which next_key_part of the 
  second range should be that of tmp. However, next_key_part is
  set to key1->next_key_part ("5 <= J <= 5") instead of 
  tmp->next_key_part (empty). Fixing this gives the correct but
  not optimal ranges:
  "NULL < I < 6",
  "6 <= I <= 6 AND 5 <= J <= 5",
  "6 < I < 8",
  "8 <= I <= 8",
  "8 < I"
  
  A second problem can be seen above: key_or() may create 
  adjacent ranges that could be replaced with a single range. 
  Fixes for this is also included in the patch so that the range
  above becomes correct AND optimal:
  "NULL < I < 6",
  "6 <= I <= 6 AND 5 <= J <= 5",
  "6 < I"
  
  Merging adjacent ranges like this gives a slightly lower cost 
  estimate for the range access.

revno: 3363.3.16
revision-id: jorgen.loland@oracle.com-20110506132631-5wickj6dvrh1dpj6
parent: alexander.nozdrin@oracle.com-20110506132138-46459va9vcbd4nz0
committer: Jorgen Loland <jorgen.loland@oracle.com>
branch nick: mysql-trunk-11765831
timestamp: Fri 2011-05-06 15:26:31 +0200
message:
  BUG#11765831: 'RANGE ACCESS' MAY INCORRECTLY FILTER
                AWAY QUALIFYING ROWS

  Preparation patch (does not include fix for the bug):

   * Extensively document key_or()
   * Remove tab indentations from key_or()
   * Minor code changes like using existing utility functions
     in key_or()

Problem was the parsing of test suite files for various tags and options.
This was done inefficiently, and include files were re-parsed for every
place they were included. This caused a delay of 20 seconds or so before
the first test started to run.

By parsing more efficiently and re-using first parse for subsequent
inclusion of the same file, time spent parsing is reduced to less than
1 second, and start appears instantaneous.

(With this patch, full ./mtr runs in 3 minutes on my laptop (release
build.)

mysql-test/suite/innodb_plugin/t/innodb_bug52663.test:
  Test is fairly slow, so try to avoid getting stuck with it at the end
  while other workers are idle.

This problem could be observed for queries with nested outer joins
for which the not_exist optimization were applicable. 
The problem was caused by the code of the patch for bug #49322
that erroneously forced the return to the previous nested loop
level when the join algorithm successfully builds a partial record
for an embedded outer to which the not_exist optimization could be
applied.
Actually the immediate return to the previous nested loops level
is correct only if this partial record is rejected by a predicate
pushed down to one of the inner tables of this outer join. Otherwise
attempts to find extensions of this record must be made.

sql/sql_expression_cache.cc:
  Do not go on disk if hit rate is not good.
  Local hit/miss counters added.
sql/sql_expression_cache.h:
  Local hit/miss counters added.

Fixed lp:814237: Wrong mutex usage in Aria


storage/maria/ma_bitmap.c:
  Added call to _ma_bitmap_mark_file_changed() when flushing bitmap. This fixes lp:814237

scripts/mysqldumpslow.sh:
  Remove not used --basedir option
  Ensure that the last --datadir option is used from the my.cnf files.

The bug happens when one uses MAX_ROWS=# with Aria & row_format=page and one insert more than # rows.


mysql-test/mysql-test-run.pl:
  Ignore table is full error messages
mysql-test/suite/maria/r/max_length.result:
  Test case for 'Table is full'
mysql-test/suite/maria/t/max_length.test:
  Test case for 'Table is full'
storage/maria/ma_bitmap.c:
  Ensure that we don't allocate bits outside of max_data_file_size.
  Adjust max_data_file_size based on bitmap alignments.
  Backport fix to adjust wrong first_bitmap_with_space.
storage/maria/ma_blockrec.c:
  Calculate value of max_data_file_length
storage/maria/ma_blockrec.h:
  Updated prototype for _ma_bitmap_init()
storage/maria/ma_check.c:
  Give warnings if file sizes are above max file sizes.
  Give more warnings in case of errors.
  Have maria_chk write if table is recreated.
storage/maria/ma_create.c:
  Better calculation of max_data_file_length and thus data pointer length.
  Fixes some wrong pointer lengths when using MAX_ROWS=#
storage/maria/ma_open.c:
  Removed duplicate assigment.
  Use block size from file instead of global variable.
storage/maria/maria_chk.c:
  Remove -1 from printed file length
storage/maria/maria_def.h:
  Update struct st_maria_file_bitmap

the optimizer switch.

off by default.

In case of two views with subqueries it is dificult to decide about order of injected ORDER BY clauses.
A simple solution is just prohibit ORDER BY injection if there is other order by.

mysql-test/r/view.result:
  New test added, old test changed.
mysql-test/t/view.test:
  New test aded.
sql/share/errmsg.txt:
  new warning added.
sql/sql_view.cc:
  Inject ORDER BY only if there is no other one.
  
  Warning about ignoring ORDER BY in this case for EXPLAIN EXTENDED.

- Correct handling of outer joins + DuplicateWeedout (docs pending)

Fixed explains of previous patch.

mysql-test/r/explain.result:
  Fixed explains of previous patch.
mysql-test/r/join_outer.result:
  Fixed explains of previous patch.
mysql-test/r/negation_elimination.result:
  Fixed explains of previous patch.
mysql-test/r/view.result:
  Fixed explains of previous patch.
mysql-test/suite/innodb/r/innodb_mysql.result:
  Removed duplicate test suite.
mysql-test/suite/innodb/t/innodb_mysql.test:
  Removed duplicate test suite.
mysql-test/suite/innodb_plugin/r/innodb_mysql.result:
  Removed duplicate test suite.
mysql-test/suite/innodb_plugin/t/innodb_mysql.test:
  Removed duplicate test suite.
sql/opt_range.h:
  Removed incorrect fix.
sql/records.cc:
  Removed incorrect fix.

There are 2 volatile condition constructions AND/OR constructions and fields(references) when first
good supported to be top elements of conditions because it is normal practice
(see copy_andor_structure for example) fields without any expression in the condition is really rare
and mostly useless case however it could lead to problems when optimiser changes/moves them unaware
of other variables referring to them. An easy solution of this problem is just to replace single field
in a condition with equivalent expression well supported by the server (<field> -> <field> != 0).

mysql-test/r/view.result:
  New test added.
mysql-test/t/view.test:
  New test added.
sql/sql_parse.cc:
  <field> -> <field> != 0
sql/sql_yacc.yy:
  <field> -> <field> != 0

Do not make substitution of a single-row table if it is an inner
table of an outer join with on expression containing an expensive
subquery.

An aggregating query over an empty set of a join of two tables
with a rejecting HAVING clause erroneously could return a row.
It could happen in the cases when the optimizer made a conclusion
that the aggregating set was empty.
Wrong results were produced because the server missed initial
setting for aggregation functions in the mentioned cases.
      

The function matching_cond should take into account that
there may be always false constant conjunctive conditions
that has not been evaluated yet,for example, conjunctive
conditions with non-correlated subqueries.

of the patch for bug 780386.

ALL subquery should return TRUE if subquery rowa set is empty independently
of left part.  The problem was that Item_func_(eq,ne,gt,ge,lt,le) do not
call execution of second argument if first is NULL no in this case subquery
will not be executed and when Item_func_not_all calls any_value() of the
subquery or aggregation function which report that there was rows. So for
NULL < ALL (SELECT...) result was FALSE instead of TRUE.

Fix is just swapping of arguments of Item_func_(eq,ne,gt,ge,lt,le) (with
changing the operation if it is needed) so that result will be the same
(for examole a < b is equal to b > a). This fix exploit the fact that
first argument will be executed in any case.

mysql-test/r/subselect.result:
  The test suite added.
mysql-test/r/subselect_no_mat.result:
  The test suite added.
mysql-test/r/subselect_no_opts.result:
  The test suite added.
mysql-test/r/subselect_no_semijoin.result:
  The test suite added.
mysql-test/r/subselect_scache.result:
  The test suite added.
mysql-test/t/subselect.test:
  The test suite added.
sql/item_cmpfunc.cc:
  Swap arguments creation methods added.
sql/item_cmpfunc.h:
  Swap arguments creation methods added.
sql/item_subselect.cc:
  Swap arguments of the comparison.

BUG##806524: Assertion `join->best_read < 1.7976931348623157e+308 with table_elimination=on and derived_merge=on 
reset_nj_counters() used to rely on the fact that join nests have 
table->table==NULL. This ceased to be true wit new derived table
optimizations. Use test for table->nested_join!=NULL instead.

The problem was that optimizer removes some outer references (it they are
constant for example) and the list of outer items built during prepare phase is
not actual during execution phase when we need it as the cache parameters.
First solution was use pointer on pointer on outer reference Item and
initialize temporary table on demand. This solved most problem except case
when optimiser also reduce Item which contains outer references ('OR' in
this bug test suite).

The solution is to build the list of outer reference items on execution
phase (after optimization) on demand (just before temporary table creation)
by walking Item tree and finding outer references among Item_ident
(Item_field/Item_ref) and Item_sum items.

Removed depends_on list (because it is not neede any mnore for the cache, in the place where it was used it replaced with upper_refs).

Added processor (collect_outer_ref_processor) and get_cache_parameters() methods to collect outer references (or other expression parameters in future).

mysql-test/r/subselect_cache.result:
  A new test added.
mysql-test/r/subselect_scache.result:
  Changes in creating the cache and its paremeters order or adding arguments of aggregate function (which is a parameter also, but this has no influence on the result).
mysql-test/t/subselect_cache.test:
  Added a new test.
sql/item.cc:
  depends_on removed.
  
  Added processor (collect_outer_ref_processor) and get_cache_parameters() methods to collect outer references.
  
  Item_cache_wrapper collect parameters befor initialization of its cache.
sql/item.h:
  depends_on removed.
  
  Added processor (collect_outer_ref_processor) and get_cache_parameters() methods to collect outer references.
sql/item_cmpfunc.cc:
  depends_on removed.
  
  Added processor (collect_outer_ref_processor) to collect outer references.
sql/item_cmpfunc.h:
  Added processor (collect_outer_ref_processor) to collect outer references.
sql/item_subselect.cc:
  depends_on removed.
  Added processor get_cache_parameters() method to collect outer references.
sql/item_subselect.h:
  depends_on removed.
  Added processor get_cache_parameters() method to collect outer references.
sql/item_sum.cc:
  Added processor (collect_outer_ref_processor) method to collect outer references.
sql/item_sum.h:
  Added processor (collect_outer_ref_processor) and get_cache_parameters() methods to collect outer references.
sql/opt_range.cc:
  depends_on removed.
sql/sql_base.cc:
  depends_on removed.
sql/sql_class.h:
  New iterator added.
sql/sql_expression_cache.cc:
  Build of list of items resolved in outer query done just before creating expression cache on the first execution of the subquery which removes influence of optimizer removing items (all optimization already done).
sql/sql_expression_cache.h:
  Build of list of items resolved in outer query done just before creating expression cache on the first execution of the subquery which removes influence of optimizer removing items (all optimization already done).
sql/sql_lex.cc:
  depends_on removed.
sql/sql_lex.h:
  depends_on removed.
sql/sql_list.h:
  Added add_unique method to add only unique elements to the list.
sql/sql_select.cc:
  Support of new Item list added.
sql/sql_select.h:
  Support of new Item list added.

- Add testcase.