Analysis
========
Point in time recovery using mysqlbinlog containing queries
operating on temporary tables results in an error.
While writing the query log event in the binary log, the
thread id used for execution of DROP TABLE and DELETE commands
were incorrect. The thread variable 'thread_specific_used'
is used to determine whether a specific thread id is to used
while executing the statements i.e using 'SET
@@session.pseudo_thread_id'. This variable was not set
correctly for DROP TABLE query and was never set for DELETE
query. The thread id is important for temporary tables
since the tables are session specific. DROP TABLE and DELETE
queries executed using a wrong thread id resulted in errors
while applying the queries generated by mysqlbinlog utility.
Fix
===
Set the 'thread_specific_used' THD variable for DROP TABLE and
DELETE queries.
ReviewBoard: 21833
st_select_lex::handle_derived() and mysql_handle_list_of_derived() had
exactly the same implementations.
- Adding a new method LEX::handle_list_of_derived() instead
- Removing public function mysql_handle_list_of_derived()
- Reusing LEX::handle_list_of_derived() in st_select_lex::handle_derived()
Do not use merge_for_insert for commands which use SELECT because optimizer can't work with such tables.
Fixes which makes multi-delete working with normally merged views.
- When traversing JOIN_TABs with first_linear_tab/next_linear_tab(), don't forget
to enter the semi-join nest when it is the first table in the join order.
Failure to do so could cause e.g. I_S tables not to be filled.
- make multi_delete::initialize_tables() take into account that the JOIN structure may have
semi-join nests (which are not fully initialized when this function is called, they have
tab->table=NULL which caused the crash)
- Also checked multi_update::initialize_tables(): it has a different logic and needed no fixing.
If triggers are used for an insert/update/delete statement than the values of
all virtual columns must be computed as any of them may be used by the triggers.
CRASHES INNODB | TRX_STATE_NOT_STARTED
The problem was that if DELETE with subselect caused a
deadlock inside InnoDB, this deadlock was not properly
handled by the SQL layer. This meant that the SQL layer
would try to unlock the row after InnoDB had rolled
back the transaction. This caused an assertion inside
InnoDB.
This patch fixes the problem by checking for errors
reported by SQL_SELECT::skip_record() and not calling
unlock_row() if any errors have been reported.
The patch enables back constant subquery execution during
query optimization after it was disabled during the development
of MWL#89 (cost-based choice of IN-TO-EXISTS vs MATERIALIZATION).
The main idea is that constant subqueries are allowed to be executed
during optimization if their execution is not expensive.
The approach is as follows:
- Constant subqueries are recursively optimized in the beginning of
JOIN::optimize of the outer query. This is done by the new method
JOIN::optimize_constant_subqueries(). This is done so that the cost
of executing these queries can be estimated.
- Optimization of the outer query proceeds normally. During this phase
the optimizer may request execution of non-expensive constant subqueries.
Each place where the optimizer may potentially execute an expensive
expression is guarded with the predicate Item::is_expensive().
- The implementation of Item_subselect::is_expensive has been extended
to use the number of examined rows (estimated by the optimizer) as a
way to determine whether the subquery is expensive or not.
- The new system variable "expensive_subquery_limit" controls how many
examined rows are considered to be not expensive. The default is 100.
In addition, multiple changes were needed to make this solution work
in the light of the changes made by MWL#89. These changes were needed
to fix various crashes and wrong results, and legacy bugs discovered
during development.
- Don't call update_virtual_fields() if table->vfield is not set
- Don't prealloc memory for in open_tables() as this is very seldom used.
sql/records.cc:
Don't call update_virtual_fields() if table->vfield is not set
sql/sql_base.cc:
Don't prealloc memory for in open_tables() as this is very seldom used.
Don't call update_virtual_fields() if table->vfield is not set
sql/sql_delete.cc:
Don't call update_virtual_fields() if table->vfield is not set
sql/sql_handler.cc:
Don't call update_virtual_fields() if table->vfield is not set
sql/sql_join_cache.cc:
Don't call update_virtual_fields() if table->vfield is not set
Move some frequent values to local variables
sql/sql_table.cc:
Don't call update_virtual_fields() if table->vfield is not set
sql/sql_update.cc:
Don't call update_virtual_fields() if table->vfield is not set
sql/table.cc:
Assert if update_virtual_fields is called with wrong parameters
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
- If USER is given, all threads for that user is signaled
- If SOFT is used then the KILL will not be sent to the handler. This can be used to not interrupt critical things in the handler like 'REPAIR'.
Internally added more kill signals. This gives us more information of why a query/connection was killed.
- KILL_SERVER is used when server is going down. In this case the users gets ER_SHUTDOWN as the reason connection was killed.
- Changed signals to number in correct order, which makes it easier to test how the signal should affect the code.
- New error message ER_CONNECTION_KILLED if connection was killed by 'KILL CONNECTION'. Before we got error ER_SHUTDOWN.
Changed names of not used parameters KILL_QUERY & KILL_CONNCTION to mysql_kill() to not conflict with defines in the server
include/mysql.h.pp:
Updated file
include/mysql_com.h:
Changed names of not used parameters KILL_QUERY & KILL_CONNCTION to mysql_kill() to not conflict with defines in the server
mysql-test/r/kill.result:
Added test of KILL USER
mysql-test/suite/rpl/r/rpl_stm_000001.result:
Updated error code
mysql-test/suite/rpl/t/rpl_stm_000001.test:
Updated error codes
mysql-test/t/flush_read_lock_kill.test:
Updated error codes
mysql-test/t/kill.test:
Added test of KILL USER
plugin/handler_socket/handlersocket/database.cpp:
Removed THD:: from KILL
sql/debug_sync.cc:
Removed THD:: from KILL
sql/event_scheduler.cc:
Removed THD:: from KILL
sql/filesort.cc:
Removed THD:: from KILL
sql/ha_ndbcluster_binlog.cc:
Removed THD:: from KILL
sql/handler.cc:
Removed THD:: from KILL
Simplify code.
sql/lex.h:
Added new keywords HARD | SOFT
sql/log.cc:
Removed THD:: from KILL
Added testing of new error ER_CONNECTION_KILLED
sql/log_event.cc:
Removed THD:: from KILL
Added testing of new error ER_CONNECTION_KILLED
sql/mysql_priv.h:
Added new prototypes
sql/mysqld.cc:
Removed THD:: from KILL
Use KILL_SERVER_HARD signal on shutdown.
sql/scheduler.cc:
Removed THD:: from KILL
Simplify test if connection should be killed
sql/share/errmsg.txt:
New error message ER_CONNECTION_KILLED
sql/slave.cc:
Removed THD:: from KILL
sql/sp_head.cc:
Removed THD:: from KILL
sql/sql_base.cc:
Removed THD:: from KILL
sql/sql_cache.cc:
Removed THD:: from KILL
sql/sql_class.cc:
Removed THD:: from KILL
Added killed_errno()
Only signal kill to storage engine if HARD bit is set.
sql/sql_class.h:
Move KILL options out from THD to make them easier to use in sql_yacc.yy
sql/sql_connect.cc:
Removed THD:: from KILL
sql/sql_delete.cc:
Removed THD:: from KILL
sql/sql_error.cc:
Removed THD:: from KILL
sql/sql_insert.cc:
Removed THD:: from KILL
Simplifed testing if thread is killed.
sql/sql_lex.h:
Added kill options to st_lex
sql/sql_load.cc:
Removed THD:: from KILL
sql/sql_parse.cc:
Added kill options to st_lex
Simplifed and optimzed testing of thd->killed at end of query
Added support for KILL USER
Extended sql_kill() to allow use of more kill signals.
sql/sql_repl.cc:
Removed THD:: from KILL
sql/sql_show.cc:
Removed THD:: from KILL
Simplied testing if query/connection was killed
sql/sql_table.cc:
Removed THD:: from KILL
sql/sql_update.cc:
Removed THD:: from KILL
sql/sql_yacc.yy:
Added support for new KILL syntax: KILL [HARD|SOFT] [CONNECTION|QUERY] [ID | USER user_name]
storage/archive/ha_archive.cc:
Simplify compilation
storage/maria/ha_maria.cc:
Removed THD:: from KILL
Also:
1. simplified the code of the function mysql_derived_merge_for_insert.
2. moved merge of views/dt for multi-update/delete to the prepare stage.
3. the list of the references to the candidates for semi-join now is
allocated in the statement memory.
Changed the code that processing of multi-updates and multi-deletes
with multitable views at the prepare stage.
A proper solution would be: never to perform any transformations of views
before and at the prepare stage. Yet it would require re-engineering
of the code that checks privileges and updatability of views.
Ultimately this re-engineering has to be done to provide a clean solution
for INSERT/UPDATE/DELETE statements that use views.
Fixed a valgrind problem in the function TABLE::use_index.
Uncommented the failing test cases.
Commented out the failing test case from parts.partition_repair_myisam.test.
The test case has to be changed to bear the same semantics as before mwl106.
Resolved all conflicts, bad merges and fixed a few minor bugs in the code.
Commented out the queries from multi_update, view, subselect_sj, func_str,
derived_view, view_grant that failed either with crashes in ps-protocol or
with wrong results.
The failures are clear indications of some bugs in the code and these bugs
are to be fixed.
mysql-test/r/union.result:
Added test for lp:732124
mysql-test/t/union.test:
Added test for lp:732124
sql/sp_rcontext.cc:
Updated function definition for ::send_data()
sql/sp_rcontext.h:
Updated function definition for ::send_data()
sql/sql_analyse.cc:
Test if send_data() returned an error
sql/sql_class.cc:
Updated function definition for ::send_data()
sql/sql_class.h:
Changed select_result::send_data(List<Item> &items) to return -1 in case of duplicate row that should not be counted as part of LIMIT
sql/sql_cursor.cc:
Check if send_data returned error
sql/sql_delete.cc:
Updated function definition for ::send_data()
sql/sql_insert.cc:
Updated function definition for ::send_data()
sql/sql_select.cc:
Don't count rows which send_data() tells you to ignore
sql/sql_union.cc:
Inform caller that the row should be ignored. This is the real bug fix for lp:732124
sql/sql_update.cc:
Updated function definition for ::send_data()
