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
delete_dynamic() was called 9-11x per OLTP RO query + 3x per BEGIN/COMMIT.
3 calls were performed by LEX_MASTER_INFO. Added condition to call those only
for CHANGE MASTER.
1 call was performed by lock_table_names()/Hash_set/my_hash_free(). Hash_set was
supposed to be used for DDL and LOCK TABLES to gather database names, while it
was initialized/freed for DML too. In fact Hash_set didn't do any useful job
here. Hash_set was removed and MDL requests are now added directly to the list.
The rest 5-7 calls are done by optimizer, mostly by Explain_query and friends.
Since dynamic arrays are used in most cases, they can hardly be optimized.
my_hash_free() overhead dropped 0.02 -> out of radar.
delete_dynamic() overhead dropped 0.12 -> 0.04.
PROFILING::start_new_query() optimizations:
- no need to check "current": added assertion instead
- "enabled" now means "is enabled currently" instead of "was enabled at query
start". Old meaning was useless, new meaning echoes OPTION_PROFILING so
that start_new_query() can be defined in sql_profile.h.
- remnants of start_new_query() moved to sql_profile.h so it can be inlined
PROFILING::start_new_query() overhead dropped 0.08% -> out of radar.
PROFILING::set_query_source() optimizations:
- no need to check "enabled": !enabled && current is impossible
- remnants of set_query_source() moved to sql_profile.h so it can be inlined
PROFILING::set_query_source() overhead dropped 0.02% -> out of radar.
PROFILING::finish_current_query() optimizations:
- moved "current" check out to sql_profile.h so it can be inlined
PROFILING::finish_current_query() overhead dropped 0.10% -> out of radar.
THD::enter_stage() optimizations:
- stage backup code moved to THD::backup_stage(), saves one condition
- moved check for "new_stage" out to callers that actually need it
- remnants of enter_stage() moved to sql_class.h so it can be inlined
THD::enter_stage() overhead dropped 0.48% -> 0.07%.
PROFILING::status_change() optimizations:
- "status_arg" is now checked by QUERY_PROFILE::new_status()
- no need to check "enabled": !enabled && current is impossible
- remnants of status_change() moved to sql_profile.h so it can be inlined
PROFILING::status_change() overhead dropped 0.1% -> out of radar.
.. wsrep.binlog_format, wsrep.mdev_6832 fail in buildbot
Galera-3.9 logs an additional warning in the error log if
it fails to find gvwstate.dat file. Update wsrep/suite.pm.
The bug was that open_tables() returned error in case of
thd->killed() without properly calling thd->send_kill_message()
to set the correct error. This was fixed already in get_schema_column_record,
so the code was just copied to get_geometry_column_record.
UNIV_LIKELY()/UNIV_UNLIKELY() hints are supposed to improve branch prediction.
Currently, they're expected to work only if cond evaluates to TRUE or FALSE.
However there're a few conditions that may evaluate to different values, e.g.:
page/page0zip.cc: if (UNIV_LIKELY(c_stream->avail_in)) {
page/page0zip.cc: if (UNIV_LIKELY(c_stream->avail_in)) {
dict/dict0mem.cc: if (UNIV_LIKELY(i) && UNIV_UNLIKELY(!table->col_names)) {
Fixed these conditions so that they evaluate TRUE/FALSE.
In optimistic parallel replication, it is not safe to try to run a following
transaction in parallel with a DDL statement, and there is code to prevent
this.
However, the code was missing the case where the DDL is the very first event
after slave start. In this case, following transactions could run in
parallel with the DDL, which can cause the slave to hang or even corrupt
slave in unlucky cases.
on REPAIR don't do table-specific stuff for views
(because even if the view has a temp table opened for it,
it's not opened all the way down the engine. In particular,
Aria crashes in maria_status() because MARIA_HA* info - that is
table->table->file->file - is NULL)
table
Performance schema discovery fails if connection has no active database set.
This happened due to restriction in SQL parser: table name with no database name
is ambiguous in such case.
Fixed by temporary substitution of default database with being discovered table
database.
XA COMMIT/ROLLBACK of XA transaction owned by different thread may access
freed memory if that thread disconnects at the same time.
Also concurrent XA COMMIT/ROLLBACK of recovered XA transaction were not
serialized properly.
Problem was that information schema tables innodb_tablespaces_encryption and
innodb_tablespaces_scrubbing where missing required check is InnoDB enabled
or not.
Problem was that e.g. on crash recovery fil_space_crypt_close_tablespace
and fil_space_crypt_mark_space_closing access mutex that is not yet
initialized. Mutex is naturally initialized only if encryption is
configured.
modified:
tabxml.cpp
added:
xml_html.test
xml_html.result
beers.xml
coffee.htm
- Fix MDEV-7935 by suppressing error resetting code in delete_or_rename_table.
However, the issue is that this code was added because without it an assertion
was raised in some cases. Unfortunately I can't remember what were these cases.
Therefore fixing it in this case will perhaps make a new crash happening on another cases.
modified:
ha_connect.cc
- Add the UDF Json_Array_Delete.
modified:
jsonudf.cpp
in when using vio->read_timeout (and write_timeout) to set
timeouts of a new vio, as in:
vio_timeout(vio, 0, old_vio.read_timeout)
vio_timeout(vio, 0, old_vio.write_timeout)
remember that timeouts are stored in ms, but vio_timeout()'s
argument is in seconds.
Gave priority to password field when using a native authentication
plugin.
Also, prevented a user from setting an invalid auth_string, when using
native authentication.
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/
