- 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
- 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.
- 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.
- Adding a new class Item_args, represending regular function or
aggregate function arguments array.
- Adding a new class Item_func_or_sum,
a parent class for Item_func and Item_sum
- Moving Item_result_field::name() to Item_func_or_sum(),
as name() is not needed on Item_result_field level.
3RD EXECUTION OF PS
Problem:
When order by is by a column number for a group concat function
which has an outer reference, server fails in case of prepared
statements on the third execution
Analysis:
When a group concat function has order by, the fields in order by
are not resolved until execution if the input is a column number.
During execution they get resolved after the temp table gets created.
As a result they will be pointing to temp table fields which are
runtime created objects. This results in dangling pointers leading
to server failure.
Solution:
Reset the pointers for the order by fields to point to the original
arguments after execution as they are invalid.
Done in Item_func_group_concat::cleanup.
The reason for the failure was a bug in an include file on debian that causes 'struct stat'
to have different sized depending on the environment.
This patch fixes so that we always include my_global.h or my_config.h before we include any other files.
Other things:
- Removed #include <my_global.h> in some include files; Better to always do this at the top level to have as few
"always-include-this-file-first' files as possible.
- Removed usage of some include files that where already included by my_global.h or by other files.
client/mysql_plugin.c:
Use my_global.h first
client/mysqlslap.c:
Remove duplicated include files
extra/comp_err.c:
Remove duplicated include files
include/m_string.h:
Remove duplicated include files
include/maria.h:
Remove duplicated include files
libmysqld/emb_qcache.cc:
Use my_global.h first
plugin/semisync/semisync.h:
Use my_pthread.h first
sql/datadict.cc:
Use my_global.h first
sql/debug_sync.cc:
Use my_global.h first
sql/derror.cc:
Use my_global.h first
sql/des_key_file.cc:
Use my_global.h first
sql/discover.cc:
Use my_global.h first
sql/event_data_objects.cc:
Use my_global.h first
sql/event_db_repository.cc:
Use my_global.h first
sql/event_parse_data.cc:
Use my_global.h first
sql/event_queue.cc:
Use my_global.h first
sql/event_scheduler.cc:
Use my_global.h first
sql/events.cc:
Use my_global.h first
sql/field.cc:
Use my_global.h first
Remove duplicated include files
sql/field_conv.cc:
Use my_global.h first
sql/filesort.cc:
Use my_global.h first
Remove duplicated include files
sql/gstream.cc:
Use my_global.h first
sql/ha_ndbcluster.cc:
Use my_global.h first
sql/ha_ndbcluster_binlog.cc:
Use my_global.h first
sql/ha_ndbcluster_cond.cc:
Use my_global.h first
sql/ha_partition.cc:
Use my_global.h first
sql/handler.cc:
Use my_global.h first
sql/hash_filo.cc:
Use my_global.h first
sql/hostname.cc:
Use my_global.h first
sql/init.cc:
Use my_global.h first
sql/item.cc:
Use my_global.h first
sql/item_buff.cc:
Use my_global.h first
sql/item_cmpfunc.cc:
Use my_global.h first
sql/item_create.cc:
Use my_global.h first
sql/item_geofunc.cc:
Use my_global.h first
sql/item_inetfunc.cc:
Use my_global.h first
sql/item_row.cc:
Use my_global.h first
sql/item_strfunc.cc:
Use my_global.h first
sql/item_subselect.cc:
Use my_global.h first
sql/item_sum.cc:
Use my_global.h first
sql/item_timefunc.cc:
Use my_global.h first
sql/item_xmlfunc.cc:
Use my_global.h first
sql/key.cc:
Use my_global.h first
sql/lock.cc:
Use my_global.h first
sql/log.cc:
Use my_global.h first
sql/log_event.cc:
Use my_global.h first
sql/log_event_old.cc:
Use my_global.h first
sql/mf_iocache.cc:
Use my_global.h first
sql/mysql_install_db.cc:
Remove duplicated include files
sql/mysqld.cc:
Remove duplicated include files
sql/net_serv.cc:
Remove duplicated include files
sql/opt_range.cc:
Use my_global.h first
sql/opt_subselect.cc:
Use my_global.h first
sql/opt_sum.cc:
Use my_global.h first
sql/parse_file.cc:
Use my_global.h first
sql/partition_info.cc:
Use my_global.h first
sql/procedure.cc:
Use my_global.h first
sql/protocol.cc:
Use my_global.h first
sql/records.cc:
Use my_global.h first
sql/records.h:
Don't include my_global.h
Better to do this at the upper level
sql/repl_failsafe.cc:
Use my_global.h first
sql/rpl_filter.cc:
Use my_global.h first
sql/rpl_gtid.cc:
Use my_global.h first
sql/rpl_handler.cc:
Use my_global.h first
sql/rpl_injector.cc:
Use my_global.h first
sql/rpl_record.cc:
Use my_global.h first
sql/rpl_record_old.cc:
Use my_global.h first
sql/rpl_reporting.cc:
Use my_global.h first
sql/rpl_rli.cc:
Use my_global.h first
sql/rpl_tblmap.cc:
Use my_global.h first
sql/rpl_utility.cc:
Use my_global.h first
sql/set_var.cc:
Added comment
sql/slave.cc:
Use my_global.h first
sql/sp.cc:
Use my_global.h first
sql/sp_cache.cc:
Use my_global.h first
sql/sp_head.cc:
Use my_global.h first
sql/sp_pcontext.cc:
Use my_global.h first
sql/sp_rcontext.cc:
Use my_global.h first
sql/spatial.cc:
Use my_global.h first
sql/sql_acl.cc:
Use my_global.h first
sql/sql_admin.cc:
Use my_global.h first
sql/sql_analyse.cc:
Use my_global.h first
sql/sql_audit.cc:
Use my_global.h first
sql/sql_base.cc:
Use my_global.h first
sql/sql_binlog.cc:
Use my_global.h first
sql/sql_bootstrap.cc:
Use my_global.h first
Use my_global.h first
sql/sql_cache.cc:
Use my_global.h first
sql/sql_class.cc:
Use my_global.h first
sql/sql_client.cc:
Use my_global.h first
sql/sql_connect.cc:
Use my_global.h first
sql/sql_crypt.cc:
Use my_global.h first
sql/sql_cursor.cc:
Use my_global.h first
sql/sql_db.cc:
Use my_global.h first
sql/sql_delete.cc:
Use my_global.h first
sql/sql_derived.cc:
Use my_global.h first
sql/sql_do.cc:
Use my_global.h first
sql/sql_error.cc:
Use my_global.h first
sql/sql_explain.cc:
Use my_global.h first
sql/sql_expression_cache.cc:
Use my_global.h first
sql/sql_handler.cc:
Use my_global.h first
sql/sql_help.cc:
Use my_global.h first
sql/sql_insert.cc:
Use my_global.h first
sql/sql_lex.cc:
Use my_global.h first
sql/sql_load.cc:
Use my_global.h first
sql/sql_locale.cc:
Use my_global.h first
sql/sql_manager.cc:
Use my_global.h first
sql/sql_parse.cc:
Use my_global.h first
sql/sql_partition.cc:
Use my_global.h first
sql/sql_plugin.cc:
Added comment
sql/sql_prepare.cc:
Use my_global.h first
sql/sql_priv.h:
Added error if we use this before including my_global.h
This check is here becasue so many files includes sql_priv.h first.
sql/sql_profile.cc:
Use my_global.h first
sql/sql_reload.cc:
Use my_global.h first
sql/sql_rename.cc:
Use my_global.h first
sql/sql_repl.cc:
Use my_global.h first
sql/sql_select.cc:
Use my_global.h first
sql/sql_servers.cc:
Use my_global.h first
sql/sql_show.cc:
Added comment
sql/sql_signal.cc:
Use my_global.h first
sql/sql_statistics.cc:
Use my_global.h first
sql/sql_table.cc:
Use my_global.h first
sql/sql_tablespace.cc:
Use my_global.h first
sql/sql_test.cc:
Use my_global.h first
sql/sql_time.cc:
Use my_global.h first
sql/sql_trigger.cc:
Use my_global.h first
sql/sql_udf.cc:
Use my_global.h first
sql/sql_union.cc:
Use my_global.h first
sql/sql_update.cc:
Use my_global.h first
sql/sql_view.cc:
Use my_global.h first
sql/sys_vars.cc:
Added comment
sql/table.cc:
Use my_global.h first
sql/thr_malloc.cc:
Use my_global.h first
sql/transaction.cc:
Use my_global.h first
sql/uniques.cc:
Use my_global.h first
sql/unireg.cc:
Use my_global.h first
sql/unireg.h:
Removed inclusion of my_global.h
storage/archive/ha_archive.cc:
Added comment
storage/blackhole/ha_blackhole.cc:
Use my_global.h first
storage/csv/ha_tina.cc:
Use my_global.h first
storage/csv/transparent_file.cc:
Use my_global.h first
storage/federated/ha_federated.cc:
Use my_global.h first
storage/federatedx/federatedx_io.cc:
Use my_global.h first
storage/federatedx/federatedx_io_mysql.cc:
Use my_global.h first
storage/federatedx/federatedx_io_null.cc:
Use my_global.h first
storage/federatedx/federatedx_txn.cc:
Use my_global.h first
storage/heap/ha_heap.cc:
Use my_global.h first
storage/innobase/handler/handler0alter.cc:
Use my_global.h first
storage/maria/ha_maria.cc:
Use my_global.h first
storage/maria/unittest/ma_maria_log_cleanup.c:
Remove duplicated include files
storage/maria/unittest/test_file.c:
Added comment
storage/myisam/ha_myisam.cc:
Move sql_plugin.h first as this includes my_global.h
storage/myisammrg/ha_myisammrg.cc:
Use my_global.h first
storage/oqgraph/oqgraph_thunk.cc:
Use my_config.h and my_global.h first
One could not include my_global.h before oqgraph_thunk.h (don't know why)
storage/spider/ha_spider.cc:
Use my_global.h first
storage/spider/hs_client/config.cpp:
Use my_global.h first
storage/spider/hs_client/escape.cpp:
Use my_global.h first
storage/spider/hs_client/fatal.cpp:
Use my_global.h first
storage/spider/hs_client/hstcpcli.cpp:
Use my_global.h first
storage/spider/hs_client/socket.cpp:
Use my_global.h first
storage/spider/hs_client/string_util.cpp:
Use my_global.h first
storage/spider/spd_conn.cc:
Use my_global.h first
storage/spider/spd_copy_tables.cc:
Use my_global.h first
storage/spider/spd_db_conn.cc:
Use my_global.h first
storage/spider/spd_db_handlersocket.cc:
Use my_global.h first
storage/spider/spd_db_mysql.cc:
Use my_global.h first
storage/spider/spd_db_oracle.cc:
Use my_global.h first
storage/spider/spd_direct_sql.cc:
Use my_global.h first
storage/spider/spd_i_s.cc:
Use my_global.h first
storage/spider/spd_malloc.cc:
Use my_global.h first
storage/spider/spd_param.cc:
Use my_global.h first
storage/spider/spd_ping_table.cc:
Use my_global.h first
storage/spider/spd_sys_table.cc:
Use my_global.h first
storage/spider/spd_table.cc:
Use my_global.h first
storage/spider/spd_trx.cc:
Use my_global.h first
storage/xtradb/handler/handler0alter.cc:
Use my_global.h first
storage/xtradb/handler/i_s.cc:
Use my_global.h first
Problem was that we used cache_table in some cases where it was not initialized
mysql-test/r/func_group.result:
Added test case
mysql-test/t/func_group.test:
Added test case
sql/item.cc:
Don't use cached_table if not set
sql/item_sum.cc:
Don't use cached_table
Bug#17867117 - ERROR RESULT WHEN "COUNT + DISTINCT + CASE WHEN" NEED MERGE_WALK
Problem:
COUNT DISTINCT gives incorrect result when it uses a Unique
Tree and its last inserted record has null value.
Here is how COUNT DISTINCT is processed, given that this query is not
using loose index scan.
When a row is produced as a result of joining tables (there is only
one table here), we store the SELECTed value in a Unique tree. This
allows elimination of any duplicates, and thus implements DISTINCT.
When we have processed all rows like this, we walk the Unique tree,
counting its elements, in Aggregator_distinct::endup() (tree->walk());
for each element we call Item_sum_count::add(). Such function wants to
ignore any NULL value, for that it checks item_sum -> args[0] ->
null_value. It is a mistake: when walking the Unique tree, the value
to be aggregated is not item_sum ->args[0] but rather table ->
field[0].
Solution:
instead of item_sum -> args[0] -> null_value, use arg_is_null(), which
knows where to look (like in fix for bug 57932).
As a consequence of this solution, we have to make arg_is_null() a
little more general:
1) Because it was so far only used for AVG() (which always has a
single argument), this function was looking at a single argument; now
that it has to work with COUNT(DISTINCT expression1,expression2), it
must look at all arguments.
2) Because we start using arg_is_null () for COUNT(DISTINCT), i.e. in
Item_sum_count::add (), it implies that we are also using it for
COUNT(no DISTINCT) (same add ()). For COUNT(no DISTINCT), the
nullness to check is that of item_sum -> args[0]. But the null_value
of such item is reliable only if val_*() has been called on it. So far
arg_is_null() was always used after a call to arg_val*(), so could
rely on null_value; but for COUNT, there is no call to arg_val*(), so
arg_is_null() has to call is_null() instead.
Testcase for 16539979 by Neeraj. Testcase for 17867117 contributed by
Xiaobin Lin from Taobao.
Bug#17867117 - ERROR RESULT WHEN "COUNT + DISTINCT + CASE WHEN" NEED MERGE_WALK
Problem:
COUNT DISTINCT gives incorrect result when it uses a Unique
Tree and its last inserted record has null value.
Here is how COUNT DISTINCT is processed, given that this query is not
using loose index scan.
When a row is produced as a result of joining tables (there is only
one table here), we store the SELECTed value in a Unique tree. This
allows elimination of any duplicates, and thus implements DISTINCT.
When we have processed all rows like this, we walk the Unique tree,
counting its elements, in Aggregator_distinct::endup() (tree->walk());
for each element we call Item_sum_count::add(). Such function wants to
ignore any NULL value, for that it checks item_sum -> args[0] ->
null_value. It is a mistake: when walking the Unique tree, the value
to be aggregated is not item_sum ->args[0] but rather table ->
field[0].
Solution:
instead of item_sum -> args[0] -> null_value, use arg_is_null(), which
knows where to look (like in fix for bug 57932).
As a consequence of this solution, we have to make arg_is_null() a
little more general:
1) Because it was so far only used for AVG() (which always has a
single argument), this function was looking at a single argument; now
that it has to work with COUNT(DISTINCT expression1,expression2), it
must look at all arguments.
2) Because we start using arg_is_null () for COUNT(DISTINCT), i.e. in
Item_sum_count::add (), it implies that we are also using it for
COUNT(no DISTINCT) (same add ()). For COUNT(no DISTINCT), the
nullness to check is that of item_sum -> args[0]. But the null_value
of such item is reliable only if val_*() has been called on it. So far
arg_is_null() was always used after a call to arg_val*(), so could
rely on null_value; but for COUNT, there is no call to arg_val*(), so
arg_is_null() has to call is_null() instead.
Testcase for 16539979 by Neeraj. Testcase for 17867117 contributed by
Xiaobin Lin from Taobao.
CONTAINING NULL
Problem:-
In MySQL, We can obtain the number of distinct expression
combinations that do not contain NULL by giving a list of
expressions in COUNT(DISTINCT).
However rows with NULL values are
incorrectly included in the count when loose index scan is
used.
Analysis:-
In case of loose index scan, we check whether the field is null or
not and increase the count in Item_sum_count::add().
But there we are checking for the first field in COUNT(DISTINCT),
not for every field. This is causing an incorrect result.
Solution:-
Check all field in Item_sum_count::add(), whether there values
are null or not. Then only increment the count.
******
Bug#17222452 - SELECT COUNT(DISTINCT A,B) INCORRECTLY COUNTS ROWS
CONTAINING NULL
Problem:-
In MySQL, We can obtain the number of distinct expression
combinations that do not contain NULL by giving a list of
expressions in COUNT(DISTINCT).
However rows with NULL values are
incorrectly included in the count when loose index scan is
used.
Analysis:-
In case of loose index scan, we check whether the field is null or
not and increase the count in Item_sum_count::add().
But there we are checking for the first field in COUNT(DISTINCT),
not for every field. This is causing an incorrect result.
Solution:-
Check all field in Item_sum_count::add(), whether there values
are null or not. Then only increment the count.
CONTAINING NULL
Problem:-
In MySQL, We can obtain the number of distinct expression
combinations that do not contain NULL by giving a list of
expressions in COUNT(DISTINCT).
However rows with NULL values are
incorrectly included in the count when loose index scan is
used.
Analysis:-
In case of loose index scan, we check whether the field is null or
not and increase the count in Item_sum_count::add().
But there we are checking for the first field in COUNT(DISTINCT),
not for every field. This is causing an incorrect result.
Solution:-
Check all field in Item_sum_count::add(), whether there values
are null or not. Then only increment the count.
******
Bug#17222452 - SELECT COUNT(DISTINCT A,B) INCORRECTLY COUNTS ROWS
CONTAINING NULL
Problem:-
In MySQL, We can obtain the number of distinct expression
combinations that do not contain NULL by giving a list of
expressions in COUNT(DISTINCT).
However rows with NULL values are
incorrectly included in the count when loose index scan is
used.
Analysis:-
In case of loose index scan, we check whether the field is null or
not and increase the count in Item_sum_count::add().
But there we are checking for the first field in COUNT(DISTINCT),
not for every field. This is causing an incorrect result.
Solution:-
Check all field in Item_sum_count::add(), whether there values
are null or not. Then only increment the count.
includes:
* remove some remnants of "Bug#14521864: MYSQL 5.1 TO 5.5 BUGS PARTITIONING"
* introduce LOCK_share, now LOCK_ha_data is strictly for engines
* rea_create_table() always creates .par file (even in "frm-only" mode)
* fix a 5.6 bug, temp file leak on dummy ALTER TABLE
!TABLES->NEXT_NAME_RESOLUTION_TABLE) || !TAB
Problem:
The context info of select query gets corrupted when a query
with group_concat having order by is present in an order by
clause of the select query. As a result, server crashes with
an assert.
Analysis:
While parsing order by for group_concat, it is presumed that
it is always present before the actual order by for the
select query.
As a result, parser uses select->order_list to populate the
order by items of group_concat and creates a select->gorder_list
to which select->order_list is copied onto. Once this is done,
it empties the select->order_list.
In the case presented in the bugpage, as order by is already
parsed when group_concat's order by is encountered, parser
presumes that it is the second order by in the select query
and creates fake_lex_unit which results in the change of
context info.
Solution:
Make group_concat's order by parsing independent of the select
sql/item_sum.cc:
Change the argument as, select->gorder_list is not pointer anymore
sql/item_sum.h:
Change the argument as, select->gorder_list is not pointer anymore
sql/mysql_priv.h:
Parsing for group_concat's order by is made independent.
As a result, add_order_to_list cannot be used anymore.
sql/sql_lex.cc:
Parsing for group_concat's order by is made independent.
As a result, add_order_to_list cannot be used anymore.
sql/sql_lex.h:
Parsing for group_concat's order by is made independent.
As a result, add_order_to_list cannot be used anymore.
sql/sql_yacc.yy:
Make group_concat's order by parsing independent of the select
queries order by.
!TABLES->NEXT_NAME_RESOLUTION_TABLE) || !TAB
Problem:
The context info of select query gets corrupted when a query
with group_concat having order by is present in an order by
clause of the select query. As a result, server crashes with
an assert.
Analysis:
While parsing order by for group_concat, it is presumed that
it is always present before the actual order by for the
select query.
As a result, parser uses select->order_list to populate the
order by items of group_concat and creates a select->gorder_list
to which select->order_list is copied onto. Once this is done,
it empties the select->order_list.
In the case presented in the bugpage, as order by is already
parsed when group_concat's order by is encountered, parser
presumes that it is the second order by in the select query
and creates fake_lex_unit which results in the change of
context info.
Solution:
Make group_concat's order by parsing independent of the select
