and 'THREAD_SAFE_CLIENT'.
As of MySQL 5.5, we no longer support non-threaded
builds. This patch removes all references to the
obsolete THREAD and THREAD_SAFE_CLIENT preprocessor
symbols. These were used to distinguish between
threaded and non-threaded builds.
Analysis:
The problem lies in filesort.cc:find_all_keys().
When find_all_keys() is called for the outer query, it resets all
of the tree sets of fields - [read,write,vcol]_set and recomputes
them with respect to sorting.
However, in the loop for each current record the procedure calls
select->skip_record(thd), which evaluates the where clause, which
in turns evaluates the subquery. The JOIN evaluation of the
subquery eventually calls Field_long::val_int to evaluate the field
alias1.f1. The assertion condition
"bitmap_is_set(table->read_set, field_index)"
fails, because the outer query changed the read_set of table "alias1".
Solution:
Restore the original read_set of the table before calling
SQL_SELECT::skip_record, then revert back to the read_set used in
find_all_keys.
- When find_all_keys() checks which table columns are needed for table scan
that is done before the sorting, it should also analyze pushed index condition.
This is achieved by remembering/checking pre-index-pushed condition.
For queries with order by clauses that employed filesort usage of
virtual column references in select lists could trigger assertion
failures. It happened because a wrong vcol_set bitmap was used for
filesort. It turned out that filesort required its own vcol_set bitmap.
Made management of the vcol_set bitmaps similar to the management
of the read_set and write_set bitmaps.
This assert checks that the server does not try to send OK to the
client if there has been some error during processing. This is done
to make sure that the error is in fact sent to the client.
The problem was that view errors during processing of WHERE conditions
in UPDATE statements where not detected by the update code. It therefore
tried to send OK to the client, triggering the assert.
The bug was only noticeable in debug builds.
This patch fixes the problem by making sure that the update code
checks for errors during condition processing and acts accordingly.
This assert checks that the server does not try to send OK to the
client if there has been some error during processing. This is done
to make sure that the error is in fact sent to the client.
The problem was that view errors during processing of WHERE conditions
in UPDATE statements where not detected by the update code. It therefore
tried to send OK to the client, triggering the assert.
The bug was only noticeable in debug builds.
This patch fixes the problem by making sure that the update code
checks for errors during condition processing and acts accordingly.
If the expression for a virtual column of table contained datetime
comparison then the execution of the second query that used this
virtual column caused a crash. It happened because the execution
of the first query that used this virtual column inserted a cached
item into the expression tree. The cached tree was allocated in
the statement memory while the expression tree was allocated in
the table memory.
Now the cached items that are inserted into expressions for virtual
columns with datetime comparisons are always allocated in the same
mem_root as the expressions for virtual columns. So now the inserted
cached items are valid for any queries that use these virtual columns.
The issue was that we didn't always check result of ha_rnd_init() which caused a problem for handlers that returned an error in this code.
- Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked.
- Added ha_rnd_init_with_error() that prints error on failure.
- Checked all usage of ha_rnd_init() and ensure we generate an error message on failures.
- Changed init_read_record() to return 1 on failure.
sql/create_options.cc:
Fixed wrong printf
sql/event_db_repository.cc:
Check result from init_read_record()
sql/events.cc:
Check result from init_read_record()
sql/filesort.cc:
Check result from ha_rnd_init()
sql/ha_partition.cc:
Check result from ha_rnd_init()
sql/ha_partition.h:
Fixed compiler warning
sql/handler.cc:
Added ha_rnd_init_with_error()
Check result from ha_rnd_init()
sql/handler.h:
Added ha_rnd_init_with_error()
Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked
sql/item_subselect.cc:
Check result from ha_rnd_init()
sql/log.cc:
Check result from ha_rnd_init()
sql/log_event.cc:
Check result from ha_rnd_init()
sql/log_event_old.cc:
Check result from ha_rnd_init()
sql/mysql_priv.h:
init_read_record() now returns error code on failure
sql/opt_range.cc:
Check result from ha_rnd_init()
sql/records.cc:
init_read_record() now returns error code on failure
Check result from ha_rnd_init()
sql/sql_acl.cc:
Check result from init_read_record()
sql/sql_cursor.cc:
Print error if ha_rnd_init() fails
sql/sql_delete.cc:
Check result from init_read_record()
sql/sql_help.cc:
Check result from init_read_record()
sql/sql_plugin.cc:
Check result from init_read_record()
sql/sql_select.cc:
Check result from ha_rnd_init()
Print error if ha_rnd_init() fails.
sql/sql_servers.cc:
Check result from init_read_record()
sql/sql_table.cc:
Check result from init_read_record()
sql/sql_udf.cc:
Check result from init_read_record()
sql/sql_update.cc:
Check result from init_read_record()
storage/example/ha_example.cc:
Don't return error on rnd_init()
storage/ibmdb2i/ha_ibmdb2i.cc:
Removed not relevant comment
Fixed compiler warnings.
queues.h and queues.c are now based on the UNIREG code and thus made BSD.
Fix code to use new queue() interface. This mostly affects how you access elements in the queue.
If USE_NET_CLEAR is not set, don't clear connection from unexpected characters. This should give a speed up when doing a lot of fast queries.
Fixed some code in ma_ft_boolean_search.c that had not made it from myisam/ft_boolean_search.c
include/queues.h:
Use UNIREG code base (BSD)
Changed init_queue() to take all initialization arguments.
New interface to access elements in queue
include/thr_alarm.h:
Changed to use time_t instead of ulong (portability)
Added index_in_queue, to be able to remove random element from queue in O(1)
mysys/queues.c:
Use UNIREG code base (BSD)
init_queue() and reinit_queue() now takes more initialization arguments. (No need for init_queue_ex() anymore)
Now one can tell queue_insert() to store in the element a pointer to where element is in queue. This allows one to remove elements from queue in O(1) instead of O(N)
mysys/thr_alarm.c:
Use new option in queue() to allow fast removal of elements.
Do less inside LOCK_alarm mutex.
This should give a major speed up of thr_alarm usage when there is many threads
sql/create_options.cc:
Fixed wrong printf
sql/event_queue.cc:
Use new queue interface()
sql/filesort.cc:
Use new queue interface()
sql/ha_partition.cc:
Use new queue interface()
sql/ha_partition.h:
Fixed compiler warning
sql/item_cmpfunc.cc:
Fixed compiler warning
sql/item_subselect.cc:
Use new queue interface()
Removed not used variable
sql/net_serv.cc:
If USE_NET_CLEAR is not set, don't clear connection from unexpected characters.
This should give a speed up when doing a lot of fast queries at the disadvantage that if there is a bug in the client protocol the connection will be dropped instead of being unnoticed.
sql/opt_range.cc:
Use new queue interface()
Fixed compiler warnings
sql/uniques.cc:
Use new queue interface()
storage/maria/ma_ft_boolean_search.c:
Copy code from myisam/ft_boolean_search.c
Use new queue interface()
storage/maria/ma_ft_nlq_search.c:
Use new queue interface()
storage/maria/ma_sort.c:
Use new queue interface()
storage/maria/maria_pack.c:
Use new queue interface()
Use queue_fix() instead of own loop to fix queue.
storage/myisam/ft_boolean_search.c:
Use new queue interface()
storage/myisam/ft_nlq_search.c:
Use new queue interface()
storage/myisam/mi_test_all.sh:
Remove temporary file from last run
storage/myisam/myisampack.c:
Use new queue interface()
Use queue_fix() instead of own loop to fix queue.
storage/myisam/sort.c:
Use new queue interface()
storage/myisammrg/myrg_queue.c:
Use new queue interface()
storage/myisammrg/myrg_rnext.c:
Use new queue interface()
storage/myisammrg/myrg_rnext_same.c:
Use new queue interface()
storage/myisammrg/myrg_rprev.c:
Use new queue interface()
If a virtual column was used in the ORDER BY clause of a query
and some of the columns this virtual column was based upon were
not referenced anywhere in the query then the execution of the
query could cause an assertion failure.
It happened because in this case the bitmap of the columns used
for ordering keys was not formed correctly.
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.
client/mysqldump.c:
Pass my_free directly as its signature is compatible with the
callback type -- which wasn't the case for free_table_ent.
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.
Fixed failing test innodb.innodb-autoinc.test
Enabled innodb test suite
mysql-test/mysql-test-run.pl:
Enabled innodb test suite
mysql-test/r/innodb-autoinc.result:
Removed test as it exists in suite innodb
mysql-test/suite/innodb/t/disabled.def:
Removed innodb-autoinc
mysql-test/suite/innodb/t/innodb-autoinc.test:
Update to be able to run with plugin
mysql-test/t/innodb-autoinc.test:
Removed test as it exists in suite innodb
sql/filesort.cc:
Removed not used variable
sql/slave.cc:
Remove compiler warnings
storage/pbxt/src/ha_pbxt.cc:
Removed not used variable
storage/xtradb/dict/dict0crea.c:
Fixed compiler warning about unsigned comparison
support-files/compiler_warnings.supp:
Disable some not relevant warnings
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
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
column is used for ORDER BY
Problem: filesort isn't meant for null length sort data
(e.g. char(0)), that leads to a server crash.
Fix: disregard sort order if sort data record length is 0 (nothing
to sort).
mysql-test/r/select.result:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- test result.
mysql-test/t/select.test:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- test case.
sql/filesort.cc:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- assert added as filesort cannot handle null length sort data.
sql/sql_select.cc:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- don't sort null length data e.g. in case of ORDER BY CHAR(0).
column is used for ORDER BY
Problem: filesort isn't meant for null length sort data
(e.g. char(0)), that leads to a server crash.
Fix: disregard sort order if sort data record length is 0 (nothing
to sort).
----------------------------------------------------------------------
ChangeSet@1.2571, 2008-04-08 12:30:06+02:00, vvaintroub@wva. +122 -0
Bug#32082 : definition of VOID in my_global.h conflicts with Windows
SDK headers
VOID macro is now removed. Its usage is replaced with void cast.
In some cases, where cast does not make much sense (pthread_*, printf,
hash_delete, my_seek), cast is ommited.
The original code comes, as far as I know, from Google (Mark Callaghan's team) with additional work from Percona, Ourdelta and Weldon Whipple.
This code provides the same functionallity, but with a lot of changes to make it faster and better fit the MariaDB infrastucture.
Added new status variables:
- Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
- Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_sent, Rows_read
Added new variable / startup option 'userstat' to control if user statistics should be enabled or not
Added my_getcputime(); Returns cpu time used by this thread.
New FLUSH commands:
- FLUSH SLOW QUERY LOG
- FLUSH TABLE_STATISTICS
- FLUSH INDEX_STATISTICS
- FLUSH USER_STATISTICS
- FLUSH CLIENT_STATISTICS
New SHOW commands:
- SHOW CLIENT_STATISTICS
- SHOW USER_STATISTICS
- SHOW TABLE_STATISTICS
- SHOW INDEX_STATISTICS
New Information schemas:
- CLIENT_STATISTICS
- USER_STATISTICS
- INDEX_STATISTICS
- TABLE_STATISTICS
Added support for all new flush commands to mysqladmin
Added handler::ha_... wrappers for all handler read calls to do statistics counting
- Changed all code to use new ha_... calls
- Count number of read rows, changed rows and rows read trough an index
Added counting of number of bytes sent to binary log (status variable Binlog_bytes_written)
Added counting of access denied errors (status variable Access_denied_erors)
Bugs fixed:
- Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
- CLOCK_GETTIME was not propely working on Linuxm
client/mysqladmin.cc:
Added support for all new flush commmands and some common combinations:
flush-slow-log
flush-table-statistics
flush-index-statistics
flush-user-statistics
flush-client-statistics
flush-all-status
flush-all-statistics
configure.in:
Added checking if clock_gettime needs the librt.
(Fixes Bug #37639 clock_gettime is never used/enabled in Linux/Unix)
include/my_sys.h:
Added my_getcputime()
include/mysql_com.h:
Added LIST_PROCESS_HOST_LEN & new REFRESH target defines
mysql-test/r/information_schema.result:
New information schema tables added
mysql-test/r/information_schema_all_engines.result:
New information schema tables added
mysql-test/r/information_schema_db.result:
New information schema tables added
mysql-test/r/log_slow.result:
Added testing that flosh slow query logs is accepted
mysql-test/r/status_user.result:
Basic testing of user, client, table and index statistics
mysql-test/t/log_slow.test:
Added testing that flosh slow query logs is accepted
mysql-test/t/status_user-master.opt:
Ensure that we get a fresh restart before running status_user.test
mysql-test/t/status_user.test:
Basic testing of user, client, table and index statistics
mysys/my_getsystime.c:
Added my_getcputime()
Returns cpu time used by this thread.
sql/authors.h:
Updated authors to have core and original MySQL developers first.
sql/event_data_objects.cc:
Updated call to mysql_reset_thd_for_next_command()
sql/event_db_repository.cc:
Changed to use new ha_... calls
sql/filesort.cc:
Changed to use new ha_... calls
sql/ha_partition.cc:
Changed to use new ha_... calls
Fixed comment syntax
sql/handler.cc:
Changed to use new ha_... calls
Reset table statistics
Added code to update global table and index status
Added counting of rows changed
sql/handler.h:
Added table and index statistics variables
Added function reset_statistics()
Added handler::ha_... wrappers for all handler read calls to do statistics counting
Protected all normal read calls to ensure we use the new calls in the server.
Made ha_partition a friend class so that partition code can call the old read functions
sql/item_subselect.cc:
Changed to use new ha_... calls
sql/lex.h:
Added keywords for new information schema tables and flush commands
sql/log.cc:
Added flush_slow_log()
Added counting of number of bytes sent to binary log
Removed not needed test of thd (It's used before, so it's safe to use)
Added THD object to MYSQL_BIN_LOG::write_cache() to simplify statistics counting
sql/log.h:
Added new parameter to write_cache()
Added flush_slow_log() functions.
sql/log_event.cc:
Updated call to mysql_reset_thd_for_next_command()
Changed to use new ha_... calls
sql/log_event_old.cc:
Updated call to mysql_reset_thd_for_next_command()
Changed to use new ha_... calls
sql/mysql_priv.h:
Updated call to mysql_reset_thd_for_next_command()
Added new statistics functions and variables needed by these.
sql/mysqld.cc:
Added new statistics variables and structures to handle these
Added new status variables:
- Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
- Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_set, Rows_read
Added new option 'userstat' to control if user statistics should be enabled or not
sql/opt_range.cc:
Changed to use new ha_... calls
sql/opt_range.h:
Changed to use new ha_... calls
sql/opt_sum.cc:
Changed to use new ha_... calls
sql/records.cc:
Changed to use new ha_... calls
sql/set_var.cc:
Added variable 'userstat'
sql/sp.cc:
Changed to use new ha_... calls
sql/sql_acl.cc:
Changed to use new ha_... calls
Added counting of access_denied_errors
sql/sql_base.cc:
Added call to statistics functions
sql/sql_class.cc:
Added usage of org_status_var, to store status variables at start of command
Added functions THD::update_stats(), THD::update_all_stats()
Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
sql/sql_class.h:
Added new status variables to status_var
Moved variables that was not ulong in status_var last.
Added variables to THD for storing temporary values during statistics counting
sql/sql_connect.cc:
Variables and functions to calculate user and client statistics
Added counting of access_denied_errors and lost_connections
sql/sql_cursor.cc:
Changed to use new ha_... calls
sql/sql_handler.cc:
Changed to use new ha_... calls
sql/sql_help.cc:
Changed to use new ha_... calls
sql/sql_insert.cc:
Changed to use new ha_... calls
sql/sql_lex.h:
Added SQLCOM_SHOW_USER_STATS, SQLCOM_SHOW_TABLE_STATS, SQLCOM_SHOW_INDEX_STATS, SQLCOM_SHOW_CLIENT_STATS
sql/sql_parse.cc:
Added handling of:
- SHOW CLIENT_STATISTICS
- SHOW USER_STATISTICS
- SHOW TABLE_STATISTICS
- SHOW INDEX_STATISTICS
Added handling of new FLUSH commands:
- FLUSH SLOW QUERY LOGS
- FLUSH TABLE_STATISTICS
- FLUSH INDEX_STATISTICS
- FLUSH USER_STATISTICS
- FLUSH CLIENT_STATISTICS
Added THD parameter to mysql_reset_thd_for_next_command()
Added initialization and calls to user statistics functions
Added increment of statistics variables empty_queries, rows_sent and access_denied_errors.
Added counting of cpu time per query
sql/sql_plugin.cc:
Changed to use new ha_... calls
sql/sql_prepare.cc:
Updated call to mysql_reset_thd_for_next_command()
sql/sql_select.cc:
Changed to use new ha_... calls
Indentation changes
sql/sql_servers.cc:
Changed to use new ha_... calls
sql/sql_show.cc:
Added counting of access denied errors
Added function for new information schema tables:
- CLIENT_STATISTICS
- USER_STATISTICS
- INDEX_STATISTICS
- TABLE_STATISTICS
Changed to use new ha_... calls
sql/sql_table.cc:
Changed to use new ha_... calls
sql/sql_udf.cc:
Changed to use new ha_... calls
sql/sql_update.cc:
Changed to use new ha_... calls
sql/sql_yacc.yy:
Add new show and flush commands
sql/structs.h:
Add name_length to KEY to avoid some strlen
Added cache_name to KEY for fast storage of keyvalue in cache
Added structs USER_STATS, TABLE_STATS, INDEX_STATS
Added function prototypes for statistics functions
sql/table.cc:
Store db+table+index name into keyinfo->cache_name
sql/table.h:
Added new information schema tables
sql/tztime.cc:
Changed to use new ha_... calls
Added (rewritten) patch from Percona to get extended statistics in slow.log:
- Added handling of 'set' variables to set_var.cc. Changed sql_mode to use this
- Added extra logging to slow log of 'Thread_id, Schema, Query Cache hit, Rows sent and Rows examined'
- Added optional logging to slow log, through log_slow_verbosity, of query plan statistics
- Added new user variables log_slow_rate_limit, log_slow_verbosity, log_slow_filter
- Added log-slow-file as synonym for 'slow-log-file', as most slow-log variables starts with 'log-slow'
- Added log-slow-time as synonym for long-query-time
Some trivial MyISAM optimizations:
- In prepare for drop, flush key blocks
- Don't call mi_lock_database if my_disable_locking is used
KNOWN_BUGS.txt:
Updated file to reflect MariaDB and not the Maria storage engine
README:
Updated file to reflect MariaDB
mysql-test/r/log_slow.result:
Test new options for slow query log
mysql-test/r/variables.result:
Updated result (old version cut of things at 79 characters)
mysql-test/t/log_slow.test:
Test new options for slow query log
sql/Makefile.am:
Added log_slow.h
sql/event_data_objects.cc:
Removed not needed test for enable_slow_log (is done when the flag is tested elsewhere)
sql/events.cc:
Use the general make_set() function instead of 'symbolic_mode_representation'
sql/filesort.cc:
Added status for used query plans
sql/log.cc:
Reset counters if no query_length (from Percona's patch; Not sure if needed, but can do no harm)
Added extra logging to slow log of 'Thread_id, Schema, Query Cache hit, Rows sent and Rows examined'
Added optional logging to slow log, through log_slow_verbosity, of query plan statistics
Fixed wrong test of error condition
sql/log_slow.h:
Defines and variables for log_slow_verbosity and log_slow_filter
sql/mysql_priv.h:
Include log_slow.h
sql/mysqld.cc:
Added new user variables log_slow_rate_limit, log_slow_verbosity, log_slow_filter
Added log-slow-file as synonym for 'slow-log-file', as most slow-log variables starts with 'log-slow'
Added log-slow-time as synonym for long-query-time
Added note that one should use log-slow-filter instead of log-slow-admin-statements
Updated comment from 'slow_query_log_file'
sql/set_var.cc:
Added long_slow_time as synonym for long_query_time
Added new user variables log_slow_rate_limit, log_slow_verbosity, log_slow_filter
dded handling of 'set' variables to set_var.cc. Changed sql_mode to use this
sql/set_var.h:
- Added handling of 'set' variables. Changed sql_mode to use this
sql/slave.cc:
Use global filter also for slaves
sql/sp_head.cc:
Simplify saving of general_slow_log state
Use the general make_set() function instead of 'symbolic_mode_representation'
sql/sql_cache.cc:
Added status for used query plans
sql/sql_class.cc:
Remember/restore query_plan_flags over complex statements
sql/sql_class.h:
Added variables to handle extended slow log statistics
sql/sql_parse.cc:
Added status for used query plans
Added test for filtering slow_query_log
sql/sql_select.cc:
Added status for used query plans
sql/sql_show.cc:
Use the general make_set() function instead of 'symbolic_mode_representation'
sql/strfunc.cc:
Report first error (not last) if something is wrong in a set
Removed compiler warning
storage/myisam/mi_extra.c:
In prepare for drop, flush key blocks (speed optimization)
storage/myisam/mi_locking.c:
Don't call mi_lock_database if my_disable_locking is used (speed optimization)
