CPUs / Intel's ICC compile
The bug is a combination of two problems:
1. IA64/ICC MySQL binaries use glibc's qsort(), not the one in mysys.
2. The order relation implemented by join_tab_cmp() is not transitive,
i.e. it is possible to choose such a, b and c that (a < b) && (b < c)
but (c < a). This implies that result of a sort using the relation
implemented by join_tab_cmp() depends on the order in which
elements are compared, i.e. the result is implementation-specific. Since
choose_plan() uses qsort() to pre-sort the
join tables using join_tab_cmp() as a compare function, the results of
the sorting may vary depending on qsort() implementation.
It is neither possible nor important to implement a better ordering
algorithm in join_tab_cmp(). Therefore the only way to fix it is to
force our own qsort() to be used by renaming it to my_qsort(), so we don't depend
on linker to decide that.
This patch also "fixes" bug #20530: qsort redefinition violates the
standard.
- Reserver namespace and place in frm for TABLE_CHECKSUM and PAGE_CHECKSUM create options
- Added syncing of directory when creating .frm files
- Portability fixes
- Added missing cast that could cause bugs
- Code cleanups
- Made some bit functions inline
- Moved things out of myisam.h to my_handler.h to make them more accessable
- Renamed some myisam variables and defines to make them more globaly usable (as they are used outside of MyISAM)
- Fixed bugs in error conditions
- Use compiler time asserts instead of run time
- Fixed indentation
HA_EXTRA_PREPARE_FOR_DELETE -> HA_EXTRA_PREPARE_FOR_DROP as the old name was wrong
(Added a define for old value to ensure we don't break any old code)
Added HA_EXTRA_PREPARE_FOR_RENAME as a signal for rename (before we used a DROP signal which is wrong)
- Initialize error messages early to get better errors when mysqld or an engine fails to start
- Fix windows bug that query_performance_frequency was not initialized if registry code failed
- thread_stack -> my_thread_stack_size
The `SELECT col FROM t WHERE col NOT IN (col, ...) GROUP BY col'
crashed in the range optimizer.
The get_func_mm_tree function has been modified to check the
Item_func_in::array field for the NULL value before using of that
value.
ORDER BY is used
The range analysis module did not correctly signal to the
handler that a range represents a ref (EQ_RANGE flag). This causes
non-range queries like
SELECT ... FROM ... WHERE keypart_1=const, ..., keypart_n=const
ORDER BY ... FOR UPDATE
to wait for a lock unneccesarily if another running transaction uses
SELECT ... FOR UPDATE on the same table.
Fixed by setting EQ_RANGE for all range accesses that represent
an equality predicate.
Faster thr_alarm()
Added 'Opened_files' status variable to track calls to my_open()
Don't give warnings when running mysql_install_db
Added option --source-install to mysql_install_db
I had to do the following renames() as used polymorphism didn't work with Forte compiler on 64 bit systems
index_read() -> index_read_map()
index_read_idx() -> index_read_idx_map()
index_read_last() -> index_read_last_map()
between perm and temp tables. Review fixes.
The original bug report complains that if we locked a temporary table
with LOCK TABLES statement, we would not leave LOCK TABLES mode
when this temporary table is dropped.
Additionally, the bug was escalated when it was discovered than
when a temporary transactional table that was previously
locked with LOCK TABLES statement was dropped, futher actions with
this table, such as UNLOCK TABLES, would lead to a crash.
The problem originates from incomplete support of transactional temporary
tables. When we added calls to handler::store_lock()/handler::external_lock()
to operations that work with such tables, we only covered the normal
server code flow and did not cover LOCK TABLES mode.
In LOCK TABLES mode, ::external_lock(LOCK) would sometimes be called without
matching ::external_lock(UNLOCK), e.g. when a transactional temporary table
was dropped. Additionally, this table would be left in the list of LOCKed
TABLES.
The patch aims to address this inadequacy. Now, whenever an instance
of 'handler' is destroyed, we assert that it was priorly
external_lock(UNLOCK)-ed. All the places that violate this assert
were fixed.
This patch introduces no changes in behavior -- the discrepancy in
behavior will be fixed when we start calling ::store_lock()/::external_lock()
for all tables, regardless whether they are transactional or not,
temporary or not.
The following type conversions was done:
- Changed byte to uchar
- Changed gptr to uchar*
- Change my_string to char *
- Change my_size_t to size_t
- Change size_s to size_t
Removed declaration of byte, gptr, my_string, my_size_t and size_s.
Following function parameter changes was done:
- All string functions in mysys/strings was changed to use size_t
instead of uint for string lengths.
- All read()/write() functions changed to use size_t (including vio).
- All protocoll functions changed to use size_t instead of uint
- Functions that used a pointer to a string length was changed to use size_t*
- Changed malloc(), free() and related functions from using gptr to use void *
as this requires fewer casts in the code and is more in line with how the
standard functions work.
- Added extra length argument to dirname_part() to return the length of the
created string.
- Changed (at least) following functions to take uchar* as argument:
- db_dump()
- my_net_write()
- net_write_command()
- net_store_data()
- DBUG_DUMP()
- decimal2bin() & bin2decimal()
- Changed my_compress() and my_uncompress() to use size_t. Changed one
argument to my_uncompress() from a pointer to a value as we only return
one value (makes function easier to use).
- Changed type of 'pack_data' argument to packfrm() to avoid casts.
- Changed in readfrm() and writefrom(), ha_discover and handler::discover()
the type for argument 'frmdata' to uchar** to avoid casts.
- Changed most Field functions to use uchar* instead of char* (reduced a lot of
casts).
- Changed field->val_xxx(xxx, new_ptr) to take const pointers.
Other changes:
- Removed a lot of not needed casts
- Added a few new cast required by other changes
- Added some cast to my_multi_malloc() arguments for safety (as string lengths
needs to be uint, not size_t).
- Fixed all calls to hash-get-key functions to use size_t*. (Needed to be done
explicitely as this conflict was often hided by casting the function to
hash_get_key).
- Changed some buffers to memory regions to uchar* to avoid casts.
- Changed some string lengths from uint to size_t.
- Changed field->ptr to be uchar* instead of char*. This allowed us to
get rid of a lot of casts.
- Some changes from true -> TRUE, false -> FALSE, unsigned char -> uchar
- Include zlib.h in some files as we needed declaration of crc32()
- Changed MY_FILE_ERROR to be (size_t) -1.
- Changed many variables to hold the result of my_read() / my_write() to be
size_t. This was needed to properly detect errors (which are
returned as (size_t) -1).
- Removed some very old VMS code
- Changed packfrm()/unpackfrm() to not be depending on uint size
(portability fix)
- Removed windows specific code to restore cursor position as this
causes slowdown on windows and we should not mix read() and pread()
calls anyway as this is not thread safe. Updated function comment to
reflect this. Changed function that depended on original behavior of
my_pwrite() to itself restore the cursor position (one such case).
- Added some missing checking of return value of malloc().
- Changed definition of MOD_PAD_CHAR_TO_FULL_LENGTH to avoid 'long' overflow.
- Changed type of table_def::m_size from my_size_t to ulong to reflect that
m_size is the number of elements in the array, not a string/memory
length.
- Moved THD::max_row_length() to table.cc (as it's not depending on THD).
Inlined max_row_length_blob() into this function.
- More function comments
- Fixed some compiler warnings when compiled without partitions.
- Removed setting of LEX_STRING() arguments in declaration (portability fix).
- Some trivial indentation/variable name changes.
- Some trivial code simplifications:
- Replaced some calls to alloc_root + memcpy to use
strmake_root()/strdup_root().
- Changed some calls from memdup() to strmake() (Safety fix)
- Simpler loops in client-simple.c
Pushbuild fixes:
- Make MAX_SEL_ARGS smaller (even 16K records_in_range() calls is
more than it makes sense to do in typical cases)
- Don't call sel_arg->test_use_count() if we've already allocated
more than MAX_SEL_ARGs elements. The test will succeed but will take
too much time for the test suite (and not provide much value).
- Added PARAM::alloced_sel_args where we count the # of SEL_ARGs
created by SEL_ARG tree cloning operations.
- Made the range analyzer to shortcut and not do any more cloning
if we've already created MAX_SEL_ARGS SEL_ARG objects in cloning.
- Added comments about space complexity of SEL_ARG-graph
representation.
To correctly decide which predicates can be evaluated with a given table
the optimizer must know the exact set of tables that a predicate depends
on. If that mask is too wide (refer to non-existing tables) the optimizer
can erroneously skip a predicate.
One such case of wrong table usage mask were the aggregate functions.
The have a all-1 mask (meaning depend on all tables, including non-existent
ones).
Fixed by making a real used_tables mask for the aggregates. The mask is
constructed in the following way :
1. OR the table dependency masks of all the arguments of the aggregate.
2. If all the arguments of the function are from the local name resolution
context and it is evaluated in the same name resolution
context where it is referenced all the tables from that name resolution
context are OR-ed to the dependency mask. This is to denote that an
aggregate function depends on the number of rows it processes.
3. Handle correctly the case of an aggregate function optimization (such that
the aggregate function can be pre-calculated and made a constant).
Made sure that an aggregate function is never a constant (unless subject of a
specific optimization and pre-calculation).
One other flaw was revealed and fixed in the process : references were
not calling the recalculation method for used_tables of their targets.
can be specified
Currently MySQL allows one to specify what indexes to ignore during
join optimization. The scope of the current USE/FORCE/IGNORE INDEX
statement is only the FROM clause, while all other clauses are not
affected.
However, in certain cases, the optimizer
may incorrectly choose an index for sorting and/or grouping, and
produce an inefficient query plan.
This task provides the means to specify what indexes are
ignored/used for what operation in a more fine-grained manner, thus
making it possible to manually force a better plan. We do this
by extending the current IGNORE/USE/FORCE INDEX syntax to:
IGNORE/USE/FORCE INDEX [FOR {JOIN | ORDER | GROUP BY}]
so that:
- if no FOR is specified, the index hint will apply everywhere.
- if MySQL is started with the compatibility option --old_mode then
an index hint without a FOR clause works as in 5.0 (i.e, the
index will only be ignored for JOINs, but can still be used to
compute ORDER BY).
See the WL#3527 for further details.
When checking if an IN predicate can be evaluated using a key
the optimizer makes sure that all the arguments of IN are of
the same result type. To assure that it check whether
Item_func_in::array is filled in.
However Item_func_in::array is set if the types are
the same AND all the arguments are compile time constants.
Fixed by introducing Item_func_in::arg_types_compatible
flag to allow correct checking of the desired condition.
