LOAD DATA into partitioned MyISAM table
Problem was that both partitioning and myisam
used the same table_share->mutex for different protections
(auto inc and repair).
Solved by adding a specific mutex for the partitioning
auto_increment.
Also adding destroying the ha_data structure in
free_table_share (which is to be propagated
into 5.5).
This is a 5.1 ONLY patch, already fixed in 5.5+.
MDL deadlock detector".
Deadlock could have occurred when workload containing mix
of DML, DDL and FLUSH TABLES statements affecting same
set of tables was executed in heavily concurrent environment.
This deadlock occurred when several connections tried to
perform deadlock detection in metadata locking subsystem.
The first connection started traversing wait-for graph,
encountered sub-graph representing wait for flush, acquired
LOCK_open and dived into sub-graph inspection. When it has
encounterd sub-graph corresponding to wait for metadata lock
and blocked while trying to acquire rd-lock on
MDL_lock::m_rwlock (*) protecting this subgraph, since some
other thread had wr-lock on it. When this wr-lock was released
it could have happened (if there was other pending wr-lock
against this rwlock) that rd-lock from the first connection
was left unsatisfied but at the same time new rd-lock request
from the second connection sneaked in and was satisfied (for
this to be possible second rd- request should come exactly
after wr-lock is released but before pending wr-lock manages
to grab rwlock, which is possible both on Linux and in our
own rwlock implementation). If this second connection
continued traversing wait-for graph and encountered sub-graph
representing wait for flush it tried to acquire LOCK_open
and thus deadlock was created.
This patch tries to workaround this problem but not allowing
deadlock detector to lock LOCK_open mutex if some other thread
doing deadlock detection already owns it and current search
depth is greater than 0. Instead deadlock is reported.
Other possible solutions are either known to have negative
effects on performance or require much more time for proper
implementation and testing.
No test case is provided as this bug is very hard to repeat
in MTR environment but is repeatable with the help of RQG
tests.
to allow temp table operations) -- prerequisite patch #1.
Move a piece of code that initialiazes TABLE instance
after it was successfully opened into a separate function.
This function will be reused in the following patches.
TABLES <list> WITH READ LOCK are incompatible".
The problem was that FLUSH TABLES <list> WITH READ LOCK
which was issued when other connection has acquired global
read lock using FLUSH TABLES WITH READ LOCK was blocked
and has to wait until global read lock is released.
This issue stemmed from the fact that FLUSH TABLES <list>
WITH READ LOCK implementation has acquired X metadata locks
on tables to be flushed. Since these locks required acquiring
of global IX lock this statement was incompatible with global
read lock.
This patch addresses problem by using SNW metadata type of
lock for tables to be flushed by FLUSH TABLES <list> WITH
READ LOCK. It is OK to acquire them without global IX lock
as long as we won't try to upgrade those locks. Since SNW
locks allow concurrent statements using same table FLUSH
TABLE <list> WITH READ LOCK now has to wait until old
versions of tables to be flushed go away after acquiring
metadata locks. Since such waiting can lead to deadlock
MDL deadlock detector was extended to take into account
waits for flush and resolve such deadlocks.
As a bonus code in open_tables() which was responsible for
waiting old versions of tables to go away was refactored.
Now when we encounter old version of table in open_table()
we don't back-off and wait for all old version to go away,
but instead wait for this particular table to be flushed.
Such approach supported by deadlock detection should reduce
number of scenarios in which FLUSH TABLES aborts concurrent
multi-statement transactions.
Note that active FLUSH TABLES <list> WITH READ LOCK still
blocks concurrent FLUSH TABLES WITH READ LOCK statement
as the former keeps tables open and thus prevents the
latter statement from doing flush.
Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.
Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.
Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.
Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost.
The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.
Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.
use limit efficiently
Bug #36569: UPDATE ... WHERE ... ORDER BY... always does a
filesort even if not required
Also two bugs reported after QA review (before the commit
of bugs above to public trees, no documentation needed):
Bug #53737: Performance regressions after applying patch
for bug 36569
Bug #53742: UPDATEs have no effect after applying patch
for bug 36569
Execution of single-table UPDATE and DELETE statements did not use the
same optimizer as was used in the compilation of SELECT statements.
Instead, it had an optimizer of its own that did not take into account
that you can omit sorting by retrieving rows using an index.
Extra optimization has been added: when applicable, single-table
UPDATE/DELETE statements use an existing index instead of filesort. A
corresponding SELECT query would do the former.
Also handling of the DESC ordering expression has been added when
reverse index scan is applicable.
From now on most single table UPDATE and DELETE statements show the
same disk access patterns as the corresponding SELECT query. We verify
this by comparing the result of SHOW STATUS LIKE 'Sort%
Currently the get_index_for_order function
a) checks quick select index (if any) for compatibility with the
ORDER expression list or
b) chooses the cheapest available compatible index, but only if
the index scan is cheaper than filesort.
Second way is implemented by the new test_if_cheaper_ordering
function (extracted part the test_if_skip_sort_order()).
strict aliasing violations.
Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.
As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.
The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.
Conflicts:
Text conflict in mysql-test/r/archive.result
Contents conflict in mysql-test/r/innodb_bug38231.result
Text conflict in mysql-test/r/mdl_sync.result
Text conflict in mysql-test/suite/binlog/t/disabled.def
Text conflict in mysql-test/suite/rpl_ndb/r/rpl_ndb_binlog_format_errors.result
Text conflict in mysql-test/t/archive.test
Contents conflict in mysql-test/t/innodb_bug38231.test
Text conflict in mysql-test/t/mdl_sync.test
Text conflict in sql/sp_head.cc
Text conflict in sql/sql_show.cc
Text conflict in sql/table.cc
Text conflict in sql/table.h
bitmap_is_set(table->read_set, field_index))
UPDATE on an InnoDB table modifying the same index that is used
to satisfy the WHERE condition could trigger a debug assertion
under some circumstances.
Since for engines with the HA_PRIMARY_KEY_IN_READ_INDEX flag
set results of an index scan on a secondary index are appended
by the primary key value, if a query involves only columns from
the primary key and a secondary index, the latter is considered
to be covering.
That tricks mysql_update() to mark for reading only columns
from the secondary index when it does an index scan to retrieve
rows to update in case a part of that key is also being
updated. However, there may be other columns in WHERE that are
part of the primary key, but not the secondary one.
What we actually want to do in this case is to add index
columns to the existing WHERE columns bitmap rather than
replace it.
transactional SELECT and ALTER TABLE ... REBUILD PARTITION".
The goal of this patch is to decouple type of metadata
lock acquired for table by open_tables() from type of
table-level lock to be acquired on it.
To achieve this we change approach to how we determine what
type of metadata lock should be acquired on table to be open.
Now instead of inferring it at open_tables() time from flags
and type of table-level lock we rely on that type of metadata
lock is properly set at parsing time and is not changed
further.
data directory name command
The check_db_name function has been modified to validate tails of
#mysql50#-prefixed database names for compliance with MySQL 5.0
database name encoding rules (the check_table_name function call
has been reused).
Conflicts:
Text conflict in mysql-test/r/grant.result
Text conflict in mysql-test/t/grant.test
Text conflict in mysys/mf_loadpath.c
Text conflict in sql/slave.cc
Text conflict in sql/sql_priv.h
MYSQL_BIN_LOG m_table_map_version member and it's associated
functions were not used in the logic of binlogging and replication,
this patch removed all related code.
This is the 5.1 merge and extension of the fix.
The server was happily accepting paths in table name in all places a table
name is accepted (e.g. a SELECT). This allowed all users that have some
privilege over some database to read all tables in all databases in all
mysql server instances that the server file system has access to.
Fixed by :
1. making sure no path elements are allowed in quoted table name when
constructing the path (note that the path symbols are still valid in table names
when they're properly escaped by the server).
2. checking the #mysql50# prefixed names the same way they're checked for
path elements in mysql-5.0.
Adding my_global.h first in all files using
NO_EMBEDDED_ACCESS_CHECKS.
Correcting a merge problem resulting from a changed definition
of check_some_access compared to the original patches.
This patch:
- Moves all definitions from the mysql_priv.h file into
header files for the component where the variable is
defined
- Creates header files if the component lacks one
- Eliminates all include directives from mysql_priv.h
- Eliminates all circular include cycles
- Rename time.cc to sql_time.cc
- Rename mysql_priv.h to sql_priv.h
into partitioned MyISAM table
Problem was that the ha_data structure was introduced in 5.1
and only used for partitioning first, but with the intention
of be of use for others engines as well, and when used by other
engines it would clash if it also was partitioned.
Solution is to move the partitioning specific data to a separate
structure, with its own mutex (which is used for auto_increment).
Also did rename PARTITION_INFO to PARTITION_STATS since there
already exist a class named partition_info, also cleaned up
some related variables.
Conflicts:
Text conflict in client/mysqlbinlog.cc
Text conflict in mysql-test/Makefile.am
Text conflict in mysql-test/collections/default.daily
Text conflict in mysql-test/r/mysqlbinlog_row_innodb.result
Text conflict in mysql-test/suite/rpl/r/rpl_typeconv_innodb.result
Text conflict in mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test
Text conflict in mysql-test/suite/rpl/t/rpl_row_create_table.test
Text conflict in mysql-test/suite/rpl/t/rpl_slave_skip.test
Text conflict in mysql-test/suite/rpl/t/rpl_typeconv_innodb.test
Text conflict in mysys/charset.c
Text conflict in sql/field.cc
Text conflict in sql/field.h
Text conflict in sql/item.h
Text conflict in sql/item_func.cc
Text conflict in sql/log.cc
Text conflict in sql/log_event.cc
Text conflict in sql/log_event_old.cc
Text conflict in sql/mysqld.cc
Text conflict in sql/rpl_utility.cc
Text conflict in sql/rpl_utility.h
Text conflict in sql/set_var.cc
Text conflict in sql/share/Makefile.am
Text conflict in sql/sql_delete.cc
Text conflict in sql/sql_plugin.cc
Text conflict in sql/sql_select.cc
Text conflict in sql/sql_table.cc
Text conflict in storage/example/ha_example.h
Text conflict in storage/federated/ha_federated.cc
Text conflict in storage/myisammrg/ha_myisammrg.cc
Text conflict in storage/myisammrg/myrg_open.c
Conflicts:
Text conflict in mysql-test/r/partition_innodb.result
Text conflict in sql/field.h
Text conflict in sql/item.h
Text conflict in sql/item_cmpfunc.h
Text conflict in sql/item_sum.h
Text conflict in sql/log_event_old.cc
Text conflict in sql/protocol.cc
Text conflict in sql/sql_select.cc
Text conflict in sql/sql_yacc.yy
The problem is that Item_direct_view_ref which is inherited
from Item_ident updates orig_table_name and table_name with
the same values. The fix is introduction of new constructor
into Item_ident and up which updates orig_table_name and
table_name separately.
The task is to
(a) add a comment on indexes and
(b) increase the maximum length of column, table and the new index comments.
The patch committed on behalf of Yoshinori Matsunobu (Yoshinori.Matsunobu@Sun.COM).
Conflicts:
Text conflict in .bzr-mysql/default.conf
Text conflict in mysql-test/suite/rpl/r/rpl_slow_query_log.result
Text conflict in mysql-test/suite/rpl/t/rpl_slow_query_log.test
Conflict adding files to server-tools. Created directory.
Conflict because server-tools is not versioned, but has versioned children. Versioned directory.
Conflict adding files to server-tools/instance-manager. Created directory.
Conflict because server-tools/instance-manager is not versioned, but has versioned children. Versioned directory.
Contents conflict in server-tools/instance-manager/options.cc
Text conflict in sql/mysqld.cc
