Problem:-
The condition that checks for node readiness is too strict as it does
not allow SELECTs even if these selects do not access any tables.
For example,if we run
SELECT 1;
OR
SELECT @@max_allowed_packet;
Solution:-
We need not to report this error when all_tables(lex->query_tables)
is NULL:
rocksdb.cons_snapshot_read_committed test used to crash.
This happened, because
- MyRocks produces an error when one attempts to do a START TRANSACTION
WITH CONSISTENT SNAPSHOT with @@tx_isolation=REPEATABLE_READ
- MariaDB's SQL layer didn't assume that errors are possible inside
hton->start_constistent_snapshot() call.
Implementation of MDEV-7660 introduced unwanted incompatible change:
modifications under LOCK TABLES with autocommit enabled are rolled back on
disconnect. Previously everything was committed, because LOCK TABLES didn't
adjust autocommit setting.
This patch restores original behavior by reverting some changes done in
MDEV-7660:
- sql/sql_parse.cc: do not reset autocommit on LOCK TABLES
- sql/sql_base.cc: do not set autocommit on UNLOCK TABLES
- test cases: main.lock_tables_lost_commit, main.partition_explicit_prune,
rpl.rpl_switch_stm_row_mixed, tokudb.nested_txn_implicit_commit,
tokudb_bugs.db806
But it makes InnoDB tables under LOCK TABLES ... READ [LOCAL] not protected
against DML. To restore protection some changes from WL#6671 were merged,
specifically MDL_SHARED_READ_ONLY and test cases.
WL#6671 merge highlights:
- Not all tests merged.
- In MySQL LOCK TABLES ... READ acquires MDL_SHARED_READ_ONLY for all engines,
in MariaDB MDL_SHARED_READ is always acquired first and then upgraded to
MDL_SHARED_READ_ONLY for InnoDB only.
- The above allows us to omit MDL_SHARED_WRITE_LOW_PRIO implementation in
MariaDB, which is rather useless with InnoDB. In MySQL it is needed to
preserve locking behavior between low priority writes and LOCK TABLES ... READ
for non-InnoDB engines (covered by sys_vars.sql_low_priority_updates_func).
- Omitted HA_NO_READ_LOCAL_LOCK, we rely on lock_count() instead.
- Omitted "piglets": in MariaDB stream of DML against InnoDB table may lead to
concurrent LOCK TABLES ... READ starvation.
- HANDLER ... OPEN acquires MDL_SHARED_READ instead of MDL_SHARED in MariaDB.
- Omitted SNRW->X MDL lock upgrade for IMPORT/DISCARD TABLESPAECE under LOCK
TABLES.
- Omitted strong locks for views, triggers and SP under LOCK TABLES.
- Omitted IX schema lock for LOCK TABLES READ.
- Omitted deadlock weight juggling for LOCK TABLES.
Full WL#6671 merge status:
- innodb.innodb-lock: fully merged
- main.alter_table: not merged due to different HANDLER solution
- main.debug_sync: fully merged
- main.handler_innodb: not merged due to different HANDLER solution
- main.handler_myisam: not merged due to different HANDLER solution
- main.innodb_mysql_lock: fully merged
- main.insert_notembedded: fully merged
- main.lock: not merged (due to no strong locks for views)
- main.lock_multi: not merged
- main.lock_sync: fully merged (partially in MDEV-7660)
- main.mdl_sync: not merged
- main.partition_debug_sync: not merged due to different HANDLER solution
- main.status: fully merged
- main.view: fully merged
- perfschema.mdl_func: not merged (no such test in MariaDB)
- perfschema.table_aggregate_global_2u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_global_2u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_global_4u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_global_4u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_hist_2u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_hist_2u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_hist_4u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_hist_4u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_thread_2u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_thread_2u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_thread_4u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_aggregate_thread_4u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_global_2u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_global_2u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_global_4u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_global_4u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_hist_2u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_hist_2u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_hist_4u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_hist_4u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_thread_2u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_thread_2u_3t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_thread_4u_2t: not merged (didn't fail in MariaDB)
- perfschema.table_lock_aggregate_thread_4u_3t: not merged (didn't fail in MariaDB)
- sys_vars.sql_low_priority_updates_func: not merged
- include/thr_rwlock.h: not merged, rw_pr_lock_assert_write_owner and
rw_pr_lock_assert_not_write_owner are macros in MariaDB
- sql/handler.h: not merged (HA_NO_READ_LOCAL_LOCK)
- sql/mdl.cc: partially merged (MDL_SHARED_READ_ONLY only)
- sql/mdl.h: partially merged (MDL_SHARED_READ_ONLY only)
- sql/lock.cc: fully merged
- sql/sp_head.cc: not merged
- sql/sp_head.h: not merged
- sql/sql_base.cc: partially merged (MDL_SHARED_READ_ONLY only)
- sql/sql_base.h: not merged
- sql/sql_class.cc: fully merged
- sql/sql_class.h: fully merged
- sql/sql_handler.cc: merged partially (different solution in MariaDB)
- sql/sql_parse.cc: partially merged, mostly omitted low priority write part
- sql/sql_reload.cc: not merged comment change
- sql/sql_table.cc: not merged SNRW->X upgrade for IMPORT/DISCARD TABLESPACE
- sql/sql_view.cc: not merged
- sql/sql_yacc.yy: not merged (MDL_SHARED_WRITE_LOW_PRIO, MDL_SHARED_READ_ONLY)
- sql/table.cc: not merged (MDL_SHARED_WRITE_LOW_PRIO)
- sql/table.h: not merged (MDL_SHARED_WRITE_LOW_PRIO)
- sql/trigger.cc: not merged
- storage/innobase/handler/ha_innodb.cc: merged store_lock()/lock_count()
changes (in MDEV-7660), didn't merge HA_NO_READ_LOCAL_LOCK
- storage/innobase/handler/ha_innodb.h: fully merged in MDEV-7660
- storage/myisammrg/ha_myisammrg.cc: not merged comment change
- storage/perfschema/table_helper.cc: not merged (no MDL support in MariaDB PFS)
- unittest/gunit/mdl-t.cc: not merged
- unittest/gunit/mdl_sync-t.cc: not merged
MariaDB specific changes:
- handler.heap: different HANDLER solution, MDEV-7660
- handler.innodb: different HANDLER solution, MDEV-7660
- handler.interface: different HANDLER solution, MDEV-7660
- handler.myisam: different HANDLER solution, MDEV-7660
- main.mdl_sync: MDEV-7660 specific changes
- main.partition_debug_sync: removed test due to different HANDLER solution,
MDEV-7660
- main.truncate_coverage: removed test due to different HANDLER solution,
MDEV-7660
- mysql-test/include/mtr_warnings.sql: additional cleanup, MDEV-7660
- mysql-test/lib/v1/mtr_report.pl: additional cleanup, MDEV-7660
- plugin/metadata_lock_info/metadata_lock_info.cc: not in MySQL
- sql/sql_handler.cc: MariaDB specific fix for mysql_ha_read(), MDEV-7660
Tasks:-
Changes in wsrep_dirty_reads variable
1.) Global + Session scope (Current: session-only)
2.) Can be set using command line.
3.) Allow all commands that do not change data (besides SELECT)
4.) Allow prepared Statements that do not change data
5.) Works with wsrep_sync_wait enabled
Tasks:-
Changes in wsrep_dirty_reads variable
1.) Global + Session scope (Current: session-only)
2.) Can be set using command line.
3.) Allow all commands that do not change data (besides SELECT)
4.) Allow prepared Statements that do not change data
5.) Works with wsrep_sync_wait enabled
Tasks:-
Changes in wsrep_dirty_reads variable
1.) Global + Session scope (Current: session-only)
2.) Can be set using command line.
3.) Allow all commands that do not change data (besides SELECT)
4.) Allow prepared Statements that do not change data
5.) Works with wsrep_sync_wait enabled
* remove old 5.2+ InnoDB support for virtual columns
* enable corresponding parts of the innodb-5.7 sources
* copy corresponding test cases from 5.7
* copy detailed Alter_inplace_info::HA_ALTER_FLAGS flags from 5.7
- and more detailed detection of changes in fill_alter_inplace_info()
* more "innodb compatibility hooks" in sql_class.cc to
- create/destroy/reset a THD (used by background purge threads)
- find a prelocked table by name
- open a table (from a background purge thread)
* different from 5.7:
- new service thread "thd_destructor_proxy" to make sure all THDs are
destroyed at the correct point in time during the server shutdown
- proper opening/closing of tables for vcol evaluations in
+ FK checks (use already opened prelocked tables)
+ purge threads (open the table, MDLock it, add it to tdc, close
when not needed)
- cache open tables in vc_templ
- avoid unnecessary allocations, reuse table->record[0] and table->s->default_values
- not needed in 5.7, because it overcalculates:
+ tell the server to calculate vcols for an on-going inline ADD INDEX
+ calculate vcols for correct error messages
* update other engines (mroonga/tokudb) accordingly
Problem:-
The condition that checks for node readiness is too strict as it does
not allow SELECTs even if these selects do not access any tables.
For example,if we run
SELECT 1;
OR
SELECT @@max_allowed_packet;
Solution:-
We need not to report this error when all_tables(lex->query_tables)
is NULL:
Problem:-
The condition that checks for node readiness is too strict as it does
not allow SELECTs even if these selects do not access any tables.
For example,if we run
SELECT 1;
OR
SELECT @@max_allowed_packet;
Solution:-
We need not to report this error when all_tables(lex->query_tables)
is NULL:
for InnoDB tables"
Don't use thr_lock.c locks for InnoDB tables. Below is list of changes that
were needed to implement this:
- HANDLER OPEN acquireis MDL_SHARED_READ instead of MDL_SHARED
- HANDLER READ calls external_lock() even if SE is not going to be locked by
THR_LOCK
- InnoDB lock wait timeouts are now honored which are much shorter by default
than server lock wait timeouts (1 year vs 50 seconds)
- with @@autocommit= 1 LOCK TABLES disables autocommit implicitely, though
user still sees @@autocommt= 1
- the above starts implicit transaction
- transactions started by LOCK TABLES are now rolled back on disconnect
(previously everything was committed due to autocommit)
- transactions started by LOCK TABLES are now rolled back by ROLLBACK
(previously everything was committed due to autocommit)
- it is now impossible to change BINLOG_FORMAT under LOCK TABLES (at least
to statement) due to running transaction
- LOCK TABLES WRITE is additionally handled by MDL
- ...in contrast LOCK TABLES READ protection against DML is pure InnoDB
- combining transactional and non-transactional tables under LOCK TABLES
may cause rolled back changes in transactional table and "committed"
changes in non-transactional table
- user may disable innodb_table_locks, which will cause LOCK TABLES to be
noop basically
Removed tests for BUG#45143 and BUG#55930 which cover InnoDB + THR_LOCK. To
operate properly these tests require code flow to go through THR_LOCK debug
sync points, which is not the case after this patch. These tests are removed
by WL#6671 as well. An alternative is to port them to different storage engine.
Problem:-
The condition that checks for node readiness is too strict as it does
not allow SELECTs even if these selects do not access any tables.
For example,if we run
SELECT 1;
OR
SELECT @@max_allowed_packet;
Solution:-
We need not to report this error when all_tables(lex->query_tables)
is NULL:
700101
ANALYSIS:
=========
To set the time 'start_time' of query in THD, current time
is obtained by calling 'gettimeofday()'. On Solaris
platform, due to some system level issues, time obtained is
invalid i.e. its either greater than 2038 (max signed value
to hold microseconds since 1970) or 1970 (0 microseconds
since 1970). In these cases, validation checks infer that
the 'start_time' is invalid and mysql server initiates the
shutdown process. But the reason for shutdown is not logged.
FIX:
====
We are now logging appropriate message when shutdown is
triggered in the above mentioned scenarios. Now, even if
the initial validation checks infer that the 'start_time'
is invalid, server shutdown is not initiated immediately.
Before initiating the server shutdown, the process of
setting 'start_time' and validating it is reiterated (for
max 5 times). If correct time is obtained in these 5
iterations then server continues to run.
Reverting a part of the patch for "MDEV-8909union parser cleanup",
as a parenthesized SELECT with PROCEDURE followed by UNION is not
disallowed by the grammar (only a non-parenthesized SELECT with PROCEDURE
followed by a UNION is disallowed grammatically).
If there are other threads running (for example binlog background
thread), then the thread count may not drop to zero at the end of
do_handle_bootstrap(). This caused an assertion and missing wakeup of
the main thread. The missing wakeup is because THD::~THD() only
signals the COND_thread_count mutex when the number of threads drops
to zero.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
- When waiting for events, start time is now counted from start of wait
- Instead of having "Connect" as "Command" for all replication threads we
now have:
- Slave_IO for Slave thread reading relay log
- Slave_SQL for slave executing SQL commands or distribution queries to
Slave workers
- Slave_worker for slave threads executin SQL commands in parallel replication
mysqld maintains a list of TABLE objects for all temporary
tables created within a session in THD. Here each table is
represented by a TABLE object.
A query referencing a particular temporary table for more
than once, however, failed with ER_CANT_REOPEN_TABLE error
because a TABLE_SHARE was allocate together with the TABLE,
so temporary tables always had only one TABLE per TABLE_SHARE.
This patch lift this restriction by separating TABLE and
TABLE_SHARE objects and storing TABLE_SHAREs for temporary
tables in a list in THD, and TABLEs in a list within their
respective TABLE_SHAREs.
use get_current_user() to distinguish user name without
a hostname and a role name.
move privilege checks inside mysql_show_grants() to remove
duplicate get_current_user() calls
This fix also fixes a connection hang when trying to do INSERT DELAYED to a crashed table.
Added crash_mysqld.inc to allow easy crash+restart of mysqld
The cause of the issue is when DROP DATABASE takes
metadata lock and is in progress through it's
execution, a concurrently running CREATE FUNCTION checks
for the existence of database which it succeeds and then it
waits on the metadata lock. Once DROP DATABASE writes to
BINLOG and finally releases the metadata lock on schema
object, the CREATE FUNCTION waiting on metadata lock
gets in it's code path and succeeds and writes to binlog.
of the type SQL_I_List<ORDER> rather then the objects of this type.
It allows to replace easily one instance of such a list for another.
Besides it will facilitate to compare two lists if they originate from the
same window specification.
In fact any direct assignment for objects of the type SQL_I_List<ORDER>
was not valid.
Fix remaining issues with wsrep_sync_wait and query cache.
- Fixes misplaced call to invalidate query cache in
Rows_log_event::do_apply_event().
Query cache was invalidated too early, and allowed old
entries to be inserted to the cache.
- Reset thd->wsrep_sync_wait_gtid on query cache hit.
THD->cleanup_after_query is not called in such cases,
and thd->wsrep_sync_wait_gtid remained initialized.
The admin commands in question are:
> OPTIMIZE
> REPAIR
> ANALYZE
For LOCAL or NO_WRITE_TO_BINLOG invocations of these commands, ie
OPTIMIZE LOCAL TABLE <t1>
they are not binlogged as expected.
Also, in addition, they are not executed under TOI.
Hence, they are not propagated to other nodes.
The effect is same as that of wsrep_on=0.
Also added tests for this.
A WSREP_DEBUG for wsrep_register_hton has also been added.
The galera_flush_local test has also been updated for verifying that effects
of NO_WRITE_TO_BINLOG / LOCAL are equivalent to wsrep_on=0 from wsrep
perspective.
(cherry picked from commit 5065122f94a8002d4da231528a46f8d9ddbffdc2)
Conflicts:
sql/sql_admin.cc
sql/sql_reload.cc
sql/wsrep_hton.cc
- Moves call wsrep_free_status() to THD::cleanup_after_query().
Wsrep status variables were previously freed only on SHOW STATUS.
- Removes valgrind suppression from mysql-test/valgrind.
"Re-factor the code for post-join operations".
The patch mainly contains the code ported from mysql-5.6 and
created for two essential architectural changes:
1. WL#5558: Resolve ORDER BY execution method at the optimization stage
2. WL#6071: Inline tmp tables into the nested loops algorithm
The first task was implemented for mysql-5.6 by Ole John Aske.
It allows to make all decisions on ORDER BY operation at the optimization
stage.
The second task implemented for mysql-5.6 by Evgeny Potemkin adds JOIN_TAB
nodes for post-join operations that require temporary tables. It allows
to execute these operations within the nested loops algorithm that used to
be used before this task only for join queries. Besides these task moves
all planning on the execution of these operations from the execution phase
to the optimization phase.
Some other re-factoring changes of mysql-5.6 were pulled in, mainly because
it was easier to pull them in than roll them back. In particular all
changes concerning Ref_ptr_array were incorporated.
The port required some changes in the MariaDB code that concerned the
functionality of EXPLAIN and ANALYZE. This was done mainly by Sergey
Petrunia.
Creating a CONNECT object on client connect and pass this to the working thread which creates the THD.
Split LOCK_thread_count to different mutexes
Added LOCK_thread_start to syncronize threads
Moved most usage of LOCK_thread_count to dedicated functions
Use next_thread_id() instead of thread_id++
Other things:
- Thread id now starts from 1 instead of 2
- Added cast for thread_id as thread id is now of type my_thread_id
- Made THD->host const (To ensure it's not changed)
- Removed some DBUG_PRINT() about entering/exiting mutex as these was already logged by mutex code
- Fixed that aborted_connects and connection_errors_internal are counted in all cases
- Don't take locks for current_linfo when we set it (not needed as it was 0 before)
- Added testing if connection is killed to shortcut reading of connection data
This will allow us later in 10.2 to do a cleaner shutdown of slaves (less errors in the log)
- Add new status variables: Slaves_connected, Slaves_running and Slave_connections.
- Use MYSQL_SLAVE_NOT_RUN instead of 0 with slave_running.
- Don't print obvious extra warnings to the error log when slave is shut down normally.
The following left in semi-improved state to keep patch size reasonable:
- Field operator new: left thd_alloc(current_thd)
- Sql_alloc operator new: left thd_alloc(thd_get_current_thd())
- Item_args constructors: left thd_alloc(thd)
- Item_func_interval::fix_length_and_dec(): no THD arg, have to call current_thd
- Item_func_dyncol_exists::val_int(): same
- Item_dyncol_get::val_str(): same
- Item_dyncol_get::val_int(): same
- Item_dyncol_get::val_real(): same
- Item_dyncol_get::val_decimal(): same
- Item_singlerow_subselect::fix_length_and_dec(): same
A prerequisite change for:
- MDEV-8093 sql_yacc.yy: add %type create_field for field_spec and column_def
- MDEV-8094 sql_yacc.yy: get rid of the rules "opt_if_not_exists_table_element"
and "opt_if_exists_table_element"
- MDEV-8095 Split Create_field
Problem is that FLUSH TABLES WITH READ LOCK first blocks threads from
starting new commits, then waits for running commits to complete. But
in-order parallel replication needs commits to happen in a particular
order, so this can easily deadlock.
To fix this problem, this patch introduces a way to temporarily pause
the parallel replication worker threads. Before starting FTWRL, we let
all worker threads complete in-progress transactions, and then
wait. Then we proceed to take the global read lock. Once the lock is
obtained, we unpause the worker threads. Now commits are blocked from
starting by the global read lock, so the deadlock will no longer occur.
EXPLAIN INSERT ... SELECT tried to use SELECT's execution path. This
caused a collection of problems:
- SELECT_DESCRIBE flag was not put into select_lex->options, which
means it was not in JOIN::select_options either (except for the first
member of the UNION).
- This caused UNION members to be executed. They would attempt to write
join output rows to the output.
- (Actual cause of the crash) second join sibling would call
result->send_eof() when finished execution. Then,
Explain_query::print_explain would attempt to write to query output
again, and cause an assertion due to non-empty query output.
[EXPLAIN] INSERT .. SELECT creates a select_insert object.
select_insert calls handler->start_bulk_insert() during
initialization.
For MyISAM/Aria this requires that a matching call to
handler->end_bulk_insert() call is made.
Regular INSERT .. SELECT accomplishes this by calling either
select_result->send_eof() or select_result->abort_result_set().
EXPLAIN INSERT ... SELECT didn't call either, which resulted in
improper de-initializaiton of handler object. Make it call
abort_result_set(), which invokes handler->end_bulk_insert().
Before this, FLUSH TABLES and FLUSH TABLES t1 (REFRESH_TABLES hereafter) were executed locally,
which also had implications for GTID. MySQL async replication does
replicate FLUSH TABLES.
Hence, this commit
a) Adds REFRESH_TABLES to TOI.
b) Skips LOCK-based REFRESH_TABLES from TOI, ie. FLUSH TABLES WITH READ
LOCK and FLUSH TABLES FOR EXPORT.
c) Executes them after reload_acl_and_cache. This is done since
reload_acl_and_cache checks for thd->locked_tables_mode and does upgrade
of MDL locks accordingly. A failure here means REFRESH_TABLES cannot
run.
i) This is also important since LOCK TABLES is not replicated in
galera.
d) Test galera_flush has been modified for
i) wsrep_replicate_myisam SESSION variable.
ii) Testing REFRESH_TABLES.
iii) Testing REFRESH_TABLES + LOCK TABLES.
e) Use different WSREP_TO_ISOLATION_BEGIN for global FLUSH TABLES and FLUSH TABLES <table,>.
(MDEV-8617: Post-fix for 10.1)
* Reset THD's PS members before returning when node is
not ready
* Add CF_SKIP_WSREP_CHECK flag to COM_STMT_XXX commands
* Skip TO replication of COM_STMT_PREPAREs for MyISAM
* Updated tests
- Part 3: Adding mem_root to push_back() and push_front()
Other things:
- Added THD as an argument to some partition functions.
- Added memory overflow checking for XML tag's in read_xml()
- Added mem_root to all calls to new Item
- Added private method operator new(size_t size) to Item to ensure that
we always use a mem_root when creating an item.
This saves use once call to current_thd per Item creation
Added mandatory thd parameter to Item (and all derivative classes) constructor.
Added thd parameter to all routines that may create items.
Also removed "current_thd" from Item::Item. This reduced number of
pthread_getspecific() calls from 290 to 177 per OLTP RO transaction.
In galera cluster, when myisam replication is enabled
(wsrep_replicate_myisam=ON), DML statements are replicated
in open_tables(). However, in case of prepared statements,
for an INSERT, open_tables() gets invoked twice. Once for
COM_STMT_PREPARE (to validate and prepare INSERT) and later
for COM_STMT_EXECUTE. As a result, the command gets replicated
twice. Same happens for REPLACE, UPDATE and DELETE commands.
Fixed by adding a check to not replicate during 'prepare'
phase. Also changed the order of conditions to make it more
efficient. Lastly, in order to support wsrep_dirty_reads, made
changes to allow COM_STMT_XXX commands to continue past initial
check even when wsrep is not ready.
RENAME TABLE, unlike other DDLs, was getting replicated before
the access check was performed. As a result, the command could
get get replicated and thus executed on other nodes, even if it
fails on the originating node due to permission issues. Fixed by
moving the logic to check user privileges before replicating the
command.
THD::>save_prep_leaf_list was set to true by multi-table update
statements with mergeable selects and never reset.
Make every statement reset it at start.
THD::>save_prep_leaf_list was set to true by multi-table update
statements with mergeable selects and never reset.
Make every statement reset it at start.
[Attempt #] Make the code that handles "Prepare" phase for multi-table
UPDATE statements handle non-merged semijoins. It can encounter them when
a prepared statement is executed for the second time.
DATABASE WHEN USING TABLE ALIASES
Issue:
-----
When using table aliases for deleting, MySQL checks
privileges against the current database and not the
privileges on the actual table or database the table
resides.
SOLUTION:
---------
While checking privileges for multi-deletes,
correspondent_table should be used since it points to the
correct table and database.
Problem :
---------
The specific issue reported in this bug is with range/list column
value that is allocated and initialized by evaluating partition
expression(item tree) during execution. After evaluation the range
list value is marked fixed [part_column_list_val]. During next
execution, we don't re-evaluate the expression and use the old value
since it is marked fixed.
Solution :
----------
One way to solve the issue is to mark all column values as not fixed
during clone so that the expression is always re-evaluated once we
attempt partition_info::fix_column_value_functions() after cloning
the part_info object during execution of DDL on partitioned table.
Reviewed-by: Jimmy Yang <Jimmy.Yang@oracle.com>
Reviewed-by: Mattias Jonsson <mattias.jonsson@oracle.com>
RB: 9424
- Changed ER(ER_...) to ER_THD(thd, ER_...) when thd was known or if there was many calls to current_thd in the same function.
- Changed ER(ER_..) to ER_THD_OR_DEFAULT(current_thd, ER...) in some places where current_thd is not necessary defined.
- Removing calls to current_thd when we have access to thd
Part of this is optimization (not calling current_thd when not needed),
but part is bug fixing for error condition when current_thd is not defined
(For example on startup and end of mysqld)
Notable renames done as otherwise a lot of functions would have to be changed:
- In JOIN structure renamed:
examined_rows -> join_examined_rows
record_count -> join_record_count
- In Field, renamed new_field() to make_new_field()
Other things:
- Added DBUG_ASSERT(thd == tmp_thd) in Item_singlerow_subselect() just to be safe.
- Removed old 'tab' prefix in JOIN_TAB::save_explain_data() and use members directly
- Added 'thd' as argument to a few functions to avoid calling current_thd.
Pretend that CREATE TABLE and CREATE TEMPORARY TABLE are
two different commands internally. The user doesn't need
to know that they both are SQLCOM_CREATE_TABLE.
Same for DROP [TEMPORARY] TABLE
Initialize abs_timeout when it is about to be used. This saves one my_hrtime()
call on hot path (when we acquire MDL lock without waiting).
When filling I_S.PROCESSLIST use THD::start_utime/THD::utime_after_query instead
of THD::start_time. This allows us to save 2 clock_gettime() calls.
Overhead change:
__clock_gettime 0.13% -> 0.11% (122 -> 76 calls per OLTP RO transaction)
my_interval_timer 0.07% -> 0.06%
my_hrtime 0.04% -> 0.01%
Added THD argument to select_result and all derivative classes.
This reduces number of pthread_getspecific calls from 796 to 776 per OLTP RO
transaction.
sql_alloc() has additional costs compared to direct mem_root allocation:
- function call: it is defined in a separate translation unit and can't be
inlined
- it needs to call pthread_getspecific() to get THD::mem_root
It is called dozens of times implicitely at least by:
- List<>::push_back()
- List<>::push_front()
- new (for Sql_alloc derived classes)
- sql_memdup()
Replaced lots of implicit sql_alloc() calls with direct mem_root allocation,
passing through THD pointer whenever it is needed.
Number of sql_alloc() calls reduced 345 -> 41 per OLTP RO transaction.
pthread_getspecific() overhead dropped 0.76 -> 0.59
sql_alloc() overhed dropped 0.25 -> 0.06
1. factored XID-related functions to a separate wsrep_xid.cc unit.
2. refactored them to take refrences instead of pointers where appropriate
3. implemented wsrep_get/set_SE_position to take wsrep_uuid_t and wsrep_seqno_t instead of XID
4. call wsrep_set_SE_position() in wsrep_sst_received() to reinitialize SE checkpoint after SST was received, avoid assert() in setting code by first checking current position.
The following FLUSH commands are now executed under total
order isolation:
* FLUSH DES_KEY_FILE
* FLUSH HOSTS
* FLUSH PRIVILEGES
* FLUSH QUERY CACHE
* FLUSH STATUS
* FLUSH USER_RESOURCES
including the big commit
commit 305130361bf72726de220f3d2b2787395e10be61
Author: Marc Alff <marc.alff@oracle.com>
Date: Tue Feb 10 11:31:32 2015 +0100
WL#8354 BACKPORT DIGEST IMPROVEMENTS TO MYSQL 5.6
(with the following commits) and related changes in sql/
The following FLUSH commands are now executed under total
order isolation:
* FLUSH DES_KEY_FILE
* FLUSH HOSTS
* FLUSH PRIVILEGES
* FLUSH QUERY CACHE
* FLUSH STATUS
* FLUSH USER_RESOURCES
This patch was backported from mysql-wsrep/5.6 commit
cdea608d9a27701d76d0deec49976aa0a08b1a56
sql/sql_parse.cc: In function 'bool do_command(THD*)':
sql/sql_parse.cc:758:20: error: 'packet_length' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if ((WSREP(thd) && packet_length == packet_error) ||
[
fix sys_var->is_default() method (that was using default_val property
in a global sys_var object to track per-session state):
* move timestamp to a dedicated Sys_var_timestamp class
(in fact, rename Sys_var_session_special_double to Sys_var_timestamp)
* make session_is_default a virtual method with a special implementation
for timestamps
* other variables don't have a special behavior for default values
and can have session_is_default() to be always false.
- Renaming Item::is_bool_func() to is_bool_type(), to avoid assumption
that the item is an Item_func derivant.
- Deriving Item_func_spatial_rel from Item_bool_func rather than Item_int_func
fixed embedded server tests
MDEV-7009: SET STATEMENT min_examined_row_limit has no effect
MDEV-6948:SET STATEMENT gtid_domain_id = ... FOR has no effect (same for gtid_seq_no and server_id)
old values of SET STATENENT variables now saved in its own Query_arena and restored later
Added a SESSION-only system variable "wsrep_dirty_reads" to allow SELECT
queries to pass even when the node is not prepared to accept queries
(wsrep_ready=OFF). Added a test case.
Added a SESSION-only system variable "wsrep_dirty_reads" to allow SELECT
queries to pass even when the node is not prepared to accept queries
(wsrep_ready=OFF). Added a test case.
Added a SESSION-only system variable "wsrep_dirty_reads" to allow SELECT
queries to pass even when the node is not prepared to accept queries
(wsrep_ready=OFF). Added a test case.
