- Added sql/mariadb.h file that should be included first by files in sql
directory, if sql_plugin.h is not used (sql_plugin.h adds SHOW variables
that must be done before my_global.h is included)
- Removed a lot of include my_global.h from include files
- Removed include's of some files that my_global.h automatically includes
- Removed duplicated include's of my_sys.h
- Replaced include my_config.h with my_global.h
* various cleanups (mostly cosmetic)
* remove useless tests (that were tesing the error condition)
* optimize delete_use_source test (from 6 mins to 50 seconds,
mainly by removing two huge rollbacks at the end).
move TABLE::key_read into handler. Because in index merge and DS-MRR
there can be many handlers per table, and some of them use
key read while others don't. "keyread" is really per handler,
not per TABLE property.
- Changed error handlers interface so that they can change error level in
the handler
- Give warnings and errors when calculating virtual columns
- On insert/update error is fatal in strict mode.
- SELECT and DELETE will only give a warning if a virtual field generates an error
- Added VCOL_UPDATE_FOR_DELETE and VCOL_UPDATE_INDEX_FOR_REPLACE to be able to
easily detect in update_virtual_fields() if we should use an error
handler to mask errors or not.
multi-update was setting up read_set/vcol_set in
multi_update::initialize_tables() that is invoked after
the optimizer (JOIN::optimize_inner()). But some rows - if they're from
const tables - will be read already in the optimizer, and these rows
will not have all necessary column/vcol values.
* multi_update::initialize_tables() uses results from the optimizer
and cannot be moved to be called earlier.
* multi_update::prepare() is called before the optimizer, but
it cannot set up read_set/vcol_set, because the optimizer
might reset them (see SELECT_LEX::update_used_tables()).
As a fix I've added a new method, select_result::prepare_to_read_rows(),
it's called from inside the optimizer just before make_join_statistics().
This fixes a bug where handler::read_range_first (for example)
needed to compare vcol values that were not calculated yet.
As a bonus it fixes few cases where vcols were calculated twice
Variant #4 of the fix.
Make ORDER BY optimization functions take into account multiple
equalities. This is done in several places:
- remove_const() checks whether we can sort the first table in the
join, or we need to put rows into temp.table and then sort.
- test_if_order_by_key() checks whether there are indexes that
can be used to produce the required ordering
- make_unireg_sortorder() constructs sort criteria for filesort.
filesort and init_read_record() for the same table.
This will simplify code for WINDOW FUNCTIONS (MDEV-6115)
- Filesort_info renamed to SORT_INFO and moved to filesort.h
- filesort now returns SORT_INFO
- init_read_record() now takes a SORT_INFO parameter.
- unique declaration is moved to uniques.h
- subselect caching of buffers is now more explicit than before
- filesort_buffer is now reusable even if rec_length has changed.
- filsort_free_buffers() and free_io_cache() calls are removed
- Remove one malloc() when using get_addon_fields()
Other things:
- Added --debug-assert-on-not-freed-memory option to make it easier to
debug some not-freed-memory issues.
Assertion `inited==INDEX' failed in int handler::ha_index_first(uchar*)
The crash was because errors from init_read_record_idx() was not taken care of.
- Part 4: Removing calls to sql_alloc() and sql_calloc()
Other things:
- Added current_thd in some places to make it clear that it's called (easier to remove later)
- Move memory allocation from Item_func_case::fix_length_and_dec() to Item_func_case::fix_fields()
- Added mem_root to some new calls
- Fixed some wrong UNINIT_VAR() calls
- Fixed a bug in generate_partition_syntax() in case of errors
- Added mem_root to argument to new thread_info
- Simplified my_parse_error() call in sql_yacc.yy
- 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.
Handle the case where the optimizer decides to use
handler->delete_all_rows(), but then this call returns
HA_ERR_UNSUPPORTED and execution switches to regular
row-by-row deletion.
When detecting a statement that can make use of ha_delete_all_rows(),
we refrained from running the statement when being presented
with the analyze or explain prefix.
Step#5: changing the function remove_eq_conds() into a virtual method in Item.
It removes 6 virtual calls for Item_func::type(), and adds only 2
virtual calls for Item***::remove_eq_conds().
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
- Remove ANALYZE's timing code off the the execution path of regular
SELECTs.
- Improve the tracker that tracks counts/execution times of SELECTs or
DML statements:
= regular execution just increments counters
= ANALYZE will also collect timings.
