(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.
- 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
