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.
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.
MDEV-4489 "Replication of big5, cp932, gbk, sjis strings makes wrong values on slave"
has been fixed.
Problem:
String constants of some Asian charsets (big5,cp932,gbk,sjis)
can have backslash '\' (0x5C) in the second byte of multi-byte characters.
Replicating of such constants using the standard '\'-escaping is dangerous.
Therefore, constants of these charsets are replicated using hex notation:
INSERT INTO t1 (a) VALUES (0x815C);
However, 0xHHHH constants do not work well in some cases,
because they can behave as strings and as numbers, depending on context
(for example, depending on the data type of the column in an INSERT statement).
This SQL script was not replicated correctly with statement-based replication:
SET NAMES gbk;
PREPARE STMT FROM 'INSERT INTO t1 (a) VALUES (?)';
SET @a = '1';
EXECUTE STMT USING @a;
The INSERT statement was replicated as:
INSERT INTO t1 (a) VALUES (0x31);
'1' was correctly converted to the number 1 on master.
But the 0x31 constant was treated as number 49 on slave.
Fix:
1. Binary log now uses X'HHHH' instead of 0xHHHH constants.
2. The X'HHHH' constants now work always as strings, in all contexts.
This is the SQL standard compliant behaviour.
After the fix, the above statement is replicated as:
INSERT INTO t1 (a) VALUES (X'31');
X'31' is treated as string '1' on slave, and is correctly converted to 1.
modified:
@ mysql-test/r/ctype_cp932_binlog_stm.result
@ mysql-test/r/select.result
@ mysql-test/r/select_jcl6.result
@ mysql-test/r/select_pkeycache.result
@ mysql-test/r/user_var-binlog.result
@ mysql-test/r/varbinary.result
@ mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
@ mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result
@ mysql-test/suite/rpl/r/rpl_charset_sjis.result
@ mysql-test/suite/rpl/r/rpl_mdev382.result
@ mysql-test/suite/rpl/t/rpl_charset_sjis.test
@ mysql-test/t/ctype_cp932_binlog_stm.test
@ mysql-test/t/select.test
@ mysql-test/t/varbinary.test
Adding and updating tests
@ sql/item.cc
@ sql/item.h
@ sql/sql_yacc.yy
@ sql/sql_lex.cc
Splitting the implementations of X'HH' and 0xHH constants into two
separate classes. Fixing the parser to distinguish the two syntaxes.
@ sql/log_event.cc
Using X'HH' instead of 0xHH for binary logging for string constants
of the "dangerous" charsets.
@ sql/sql_string.h
Adding a helped method String::append_hex().
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.
This is a bug in the legacy code. It did not manifest itself because
it was masked by other bugs that were fixed by the patches for
mdev-4172 and mdev-4177.
In some rare cases when the value of the system variable join_buffer_size
was set to a number less than 256 the function JOIN_CACHE::set_constants
determined the size of an offset in the join buffer equal to 1 though
the minimal join buffer required more than 256 bytes. This could cause
a crash of the server when records from the join buffer were read.
The MIN/MAX optimizer code from the function opt_sum_query erroneously
did not take into account conjunctive conditions that did not depend on
any table, yet were not identified as constant items. These could be
items containing rand() or PS/SP parameters. These items are supposed
to be evaluated at the execution phase. That's why if such conditions
can be extracted from the WHERE condition the MIN/MAX optimization is
not applied as currently it is always done at the optimization phase.
(In 5.3 expensive subqueries are also evaluated only at the execution
phase. So, if a constant condition with such subquery can be extracted
from the WHERE clause the MIN/MAX optimization should not be applied
in 5.3.)
IF an IN/ALL/SOME predicate with a constant left part is transformed
into an EXISTS subquery the resulting subquery should not be considered
uncacheable if the right part of the predicate is not uncacheable.
Backported the function dbug_print_item() from 5.3. The function is used
only for debugging.
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.
* rename all debugging related command-line options
and variables to start from "debug-", and made them all
OFF by default.
* replace "MySQL" with "MariaDB" in error messages
* "Cast ... converted ... integer to it's ... complement"
is now a note, not a warning
* @@query_cache_strip_comments now has a session scope,
not global.
mysql-test/r/select.result:
Test case for lp:780425
mysql-test/r/select_pkeycache.result:
lp:780425
mysql-test/t/select.test:
lp:780425
sql/sql_select.cc:
Added DBUG_ASSERT to be prove some logic and later be able to simplify the code
Set implicit_grouping if we delete a GROUP BY to signal do_select() that a grouping needs to be done.
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
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.
- Set the default
- Adjust the testcases so that 'new' tests are run with optimizations turned on.
- Pull out relevant tests from "irrelevant" tests and run them with optimizations on.
- Run range.test and innodb.test with both mrr=on and mrr=off
A lot of small fixes and new test cases.
client/mysqlbinlog.cc:
Cast removed
client/mysqltest.cc:
Added missing DBUG_RETURN
include/my_pthread.h:
set_timespec_time_nsec() now only takes one argument
mysql-test/t/date_formats.test:
Remove --disable_ps_protocl as now also ps supports microseconds
mysys/my_uuid.c:
Changed to use my_interval_timer() instead of my_getsystime()
mysys/waiting_threads.c:
Changed to use my_hrtime()
sql/field.h:
Added bool special_const_compare() for fields that may convert values before compare (like year)
sql/field_conv.cc:
Added test to get optimal copying of identical temporal values.
sql/item.cc:
Return that item_int is equal if it's positive, even if unsigned flag is different.
Fixed Item_cache_str::save_in_field() to have identical null check as other similar functions
Added proper NULL check to Item_cache_int::save_in_field()
sql/item_cmpfunc.cc:
Don't call convert_constant_item() if there is nothing that is worth converting.
Simplified test when years should be converted
sql/item_sum.cc:
Mark cache values in Item_sum_hybrid as not constants to ensure they are not replaced by other cache values in compare_datetime()
sql/item_timefunc.cc:
Changed sec_to_time() to take a my_decimal argument to ensure we don't loose any sub seconds.
Added Item_temporal_func::get_time() (This simplifies some things)
sql/mysql_priv.h:
Added Lazy_string_decimal()
sql/mysqld.cc:
Added my_decimal constants max_seconds_for_time_type, time_second_part_factor
sql/table.cc:
Changed expr_arena to be of type CONVENTIONAL_EXECUTION to ensure that we don't loose any items that are created by fix_fields()
sql/tztime.cc:
TIME_to_gmt_sec() now sets *in_dst_time_gap in case of errors
This is needed to be able to detect if timestamp is 0
storage/maria/lockman.c:
Changed from my_getsystime() to set_timespec_time_nsec()
storage/maria/ma_loghandler.c:
Changed from my_getsystime() to my_hrtime()
storage/maria/ma_recovery.c:
Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/maria/unittest/trnman-t.c:
Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/xtradb/handler/ha_innodb.cc:
Added support for new time,datetime and timestamp
unittest/mysys/thr_template.c:
my_getsystime() -> my_interval_timer()
unittest/mysys/waiting_threads-t.c:
my_getsystime() -> my_interval_timer()
- "Using MRR" is no longer shown with range access.
- Instead, both range and BKA accesses will show one of the following:
= "Rowid-ordered scan"
= "Key-ordered scan"
= "Key-ordered Rowid-ordered scan"
depending on whether DS-MRR implementation will do scan keys in order, rowids in order,
or both.
- The patch also introduces a way for other storage engines/MRR implementations to
pass information to EXPLAIN output about the properties of employed MRR scans.
The bug was in the code of the patch fixing bug 698882.
With improper casting the method store_key_field::change_source_field
was called for the elements of the array TABLE_REF::key_copy that
were either of a different type or not allocated at all. This caused
crashes in some queries.
Made sure that the optimal fields are used by TABLE_REF objects
when building index access keys to joined tables.
Fixed a bug in the template function that sorts the elements of
a list using the bubble sort algorithm. The bug caused poor
performance of the function. Also added an optimization that
skips comparison with the most heavy elements that has been
already properly placed in the list.
Made the comparison of the fields belonging to the same Item_equal
more granular: fields belonging to the same table are also ordered
according to some rules.
An assertion failure was triggered for a 6-way join query that used two
join buffers.
The failure happened because every call of JOIN_CACHE::join_matching_records
saved and restored status of all tables that were accessed before the table
join_tab. It must do it only for those of them that follow the last table
using a join buffer.
