Description: When querying a subset of columns from the information_schema.TABLES
Analysis: When information about tables is collected for statements like
"SELECT ENGINE FROM I_S.TABLES" we do not perform full-blown table opens
in SE, instead we only use information from table shares from the Table
Definition Cache or .FRMs. Still in order to simplify I_S implementation
mock TABLE objects are created from TABLE_SHARE during this process.
This is done by calling open_table_from_share() function with special
arguments. Since this function always increments "Opened_tables" counter,
calls to it can be mistakingly interpreted as full-blown table opens in SE.
Note that claim that "'SELECT ENGINE FROM I_S.TABLES' statement doesn't
use Table Cache" is nevertheless factually correct. But it misses the
point, since such statements a) don't use full-blown TABLE objects and
therefore don't do table opens b) still use Table Definition Cache.
Fix: We are now incrementing the counter when db_stat(i.e open flags for ha_open(
we have considered an optimization which would use TABLE objects from
Table Cache when available instead of constructing mock TABLE objects,
but found it too intrusive for stable releases.
Add missing REAP to the test.
A later test failed with strange incorrect values for COM_SELECT
in information_schema.global_status. Since global_status is updated
at the end of session activity, it seems appropriate to ensure that
all background connections have completed before accessing it.
(I checked that the original bug still triggers the test case after
the modification with REAP).
Analysis:
The reason for the suboptimal plan when querying IS tables through a view
was that the view columns that participate in an equality are wrapped by
an Item_direct_view_ref and were not recognized as being direct column
references.
Solution:
Use the original Item_field objects via the real_item() method.
Backporting the WL#5716, "Information schema table for InnoDB
buffer pool information". Backporting revisions 2876.244.113,
2876.244.102 from mysql-trunk.
rb://1177 approved by Jimmy Yang.
* rename all debugging related command-line options
and variables to start from "debug-", and made them all
OFF by default.
* replace "MySQL" with "MariaDB" in error messages
* "Cast ... converted ... integer to it's ... complement"
is now a note, not a warning
* @@query_cache_strip_comments now has a session scope,
not global.
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
FOR CERTAIN QUERIES TO INFORMATION_SCHEMA".
The problem was that metadata locking subsystem introduced
too much overhead for queries to I_S which were processed by
opening only .FRM or .TRG files and had to scanned a lot of
tables (e.g. SELECT COUNT(*) FROM I_S.TRIGGERS was affected).
The same effect was not observed for similar queries which
performed full-blown table open in order to fill I_S table.
The problem stemmed from the fact that in case when I_S
implementation opened only .FRM or .TRG file for each table
processed it didn't release metadata lock it has acquired on
the table after finishing its processing. As result, list
of acquired metadata locks were growing until the end of
statement. Since acquisition of each new lock required
search in the list of already acquired locks performance
degraded.
The same effect is not observed when I_S implementation
performs full-blown table open for each table being
processed, as in the latter cases metadata lock on the
table is released right after table processing.
This fix addressed the problem by ensuring that I_S
implementation releases metadata lock after processing
the table in both cases of full-blown table open and in
case when only .FRM or .TRG file is read.
mysql-test/r/information_schema.result:
Added coverage for bug #12828477 - "MDL SUBSYSTEM CREATES BIG
OVERHEAD FOR CERTAIN QUERIES TO INFORMATION_SCHEMA".
mysql-test/t/information_schema.test:
Added coverage for bug #12828477 - "MDL SUBSYSTEM CREATES BIG
OVERHEAD FOR CERTAIN QUERIES TO INFORMATION_SCHEMA".
sql/sql_show.cc:
Changed fill_schema_table_from_frm() to release metadata lock
it has acquired after processing the .FRM or .TRG file for
table.
Without this step metadata locks acquired for each table
processed will be accumulated. In situation when a lot of
tables are processed by I_S query this will result in
transaction with too many metadata locks. As result
performance of acquisition of new lock will degrade.
FOR CERTAIN QUERIES TO INFORMATION_SCHEMA".
The problem was that metadata locking subsystem introduced
too much overhead for queries to I_S which were processed by
opening only .FRM or .TRG files and had to scanned a lot of
tables (e.g. SELECT COUNT(*) FROM I_S.TRIGGERS was affected).
The same effect was not observed for similar queries which
performed full-blown table open in order to fill I_S table.
The problem stemmed from the fact that in case when I_S
implementation opened only .FRM or .TRG file for each table
processed it didn't release metadata lock it has acquired on
the table after finishing its processing. As result, list
of acquired metadata locks were growing until the end of
statement. Since acquisition of each new lock required
search in the list of already acquired locks performance
degraded.
The same effect is not observed when I_S implementation
performs full-blown table open for each table being
processed, as in the latter cases metadata lock on the
table is released right after table processing.
This fix addressed the problem by ensuring that I_S
implementation releases metadata lock after processing
the table in both cases of full-blown table open and in
case when only .FRM or .TRG file is read.
A lot of small fixes and new test cases.
client/mysqlbinlog.cc:
Cast removed
client/mysqltest.cc:
Added missing DBUG_RETURN
include/my_pthread.h:
set_timespec_time_nsec() now only takes one argument
mysql-test/t/date_formats.test:
Remove --disable_ps_protocl as now also ps supports microseconds
mysys/my_uuid.c:
Changed to use my_interval_timer() instead of my_getsystime()
mysys/waiting_threads.c:
Changed to use my_hrtime()
sql/field.h:
Added bool special_const_compare() for fields that may convert values before compare (like year)
sql/field_conv.cc:
Added test to get optimal copying of identical temporal values.
sql/item.cc:
Return that item_int is equal if it's positive, even if unsigned flag is different.
Fixed Item_cache_str::save_in_field() to have identical null check as other similar functions
Added proper NULL check to Item_cache_int::save_in_field()
sql/item_cmpfunc.cc:
Don't call convert_constant_item() if there is nothing that is worth converting.
Simplified test when years should be converted
sql/item_sum.cc:
Mark cache values in Item_sum_hybrid as not constants to ensure they are not replaced by other cache values in compare_datetime()
sql/item_timefunc.cc:
Changed sec_to_time() to take a my_decimal argument to ensure we don't loose any sub seconds.
Added Item_temporal_func::get_time() (This simplifies some things)
sql/mysql_priv.h:
Added Lazy_string_decimal()
sql/mysqld.cc:
Added my_decimal constants max_seconds_for_time_type, time_second_part_factor
sql/table.cc:
Changed expr_arena to be of type CONVENTIONAL_EXECUTION to ensure that we don't loose any items that are created by fix_fields()
sql/tztime.cc:
TIME_to_gmt_sec() now sets *in_dst_time_gap in case of errors
This is needed to be able to detect if timestamp is 0
storage/maria/lockman.c:
Changed from my_getsystime() to set_timespec_time_nsec()
storage/maria/ma_loghandler.c:
Changed from my_getsystime() to my_hrtime()
storage/maria/ma_recovery.c:
Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/maria/unittest/trnman-t.c:
Changed from my_getsystime() to mmicrosecond_interval_timer()
storage/xtradb/handler/ha_innodb.cc:
Added support for new time,datetime and timestamp
unittest/mysys/thr_template.c:
my_getsystime() -> my_interval_timer()
unittest/mysys/waiting_threads-t.c:
my_getsystime() -> my_interval_timer()
Resolved all conflicts, bad merges and fixed a few minor bugs in the code.
Commented out the queries from multi_update, view, subselect_sj, func_str,
derived_view, view_grant that failed either with crashes in ps-protocol or
with wrong results.
The failures are clear indications of some bugs in the code and these bugs
are to be fixed.
and collateral changes.
* introduce my_hrtime_t, my_timediff_t, and conversion macros
* inroduce TIME_RESULT, but it can only be returned from Item::cmp_type(),
never from Item::result_type()
* pack_time/unpack_time function for "packed" representation of
MYSQL_TIME in a longlong that can be compared
* ADDTIME()/SUBTIME()/+- INTERVAL now work with TIME values
* numbers aren't quoted in EXPLAIN EXTENDED
* new column I_S.COLUMNS.DATETIME_PRECISION
* date/time values are compares to anything as date/time, not as strings or numbers.
* old timestamp(X) is no longer supported
* MYSQL_TIME to string conversion functions take precision as an argument
* unified the warnings from Field_timestamp/datetime/time/date/newdate store methods
* Field_timestamp_hires, Field_datetime_hires, Field_time_hires
* Field_temporal
* Lazy_string class to pass a value (string, number, time) polymorphically down the stack
* make_truncated_value_warning and Field::set_datetime_warning use Lazy_string as an argument, removed char*/int/double variants
* removed Field::can_be_compared_as_longlong(). Use Field::cmp_type() == INT_RESULT instead
* introduced Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
* in many cases date/time types are treated like other types, not as special cases
* greatly simplified Arg_comparator (regarding date/time/year code)
* SEC_TO_TIME is real function, not integer.
* microsecond precision in NOW, CURTIME, etc
* Item_temporal. All items derived from it only provide get_date, but no val* methods
* replication of NOW(6)
* Protocol::store(time) now takes the precision as an argument
* @@TIMESTAMP is a double
client/mysqlbinlog.cc:
remove unneded casts
include/my_sys.h:
introduce my_hrtime_t, my_timediff_t, and conversion macros
include/my_time.h:
pack_time/unpack_time, etc.
convenience functions to work with MYSQL_TIME::second_part
libmysql/libmysql.c:
str_to_time() is gone. str_to_datetime() does it now.
my_TIME_to_str() takes the precision as an argument
mysql-test/include/ps_conv.inc:
time is not equal to datetime anymore
mysql-test/r/distinct.result:
a test for an old MySQL bug
mysql-test/r/explain.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/func_default.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/func_sapdb.result:
when decimals=NOT_FIXED_DEC it means "not fixed" indeed
mysql-test/r/func_test.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/func_time.result:
ADDTIME()/SUBTIME()/+- INTERVAL now work with TIME values
mysql-test/r/having.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/information_schema.result:
new column I_S.COLUMNS.DATETIME_PRECISION
mysql-test/r/join_outer.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/metadata.result:
TIMESTAMP no longer has zerofill flag
mysql-test/r/range.result:
invalid datetime is not compared with as a string
mysql-test/r/select.result:
NO_ZERO_IN_DATE, etc only affect storage - according to the manual
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/subselect.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/sysdate_is_now.result:
when decimals=NOT_FIXED_DEC it means "not fixed" indeed
mysql-test/r/type_blob.result:
TIMESTAMP(N) is not deprecated
mysql-test/r/type_timestamp.result:
old TIMESTAMP(X) semantics is not supported anymore
mysql-test/r/union.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/r/varbinary.result:
numbers aren't quoted in EXPLAIN EXTENDED
mysql-test/t/distinct.test:
test for an old MySQL bug
mysql-test/t/func_time.test:
+- INTERVAL now works with TIME values
mysql-test/t/select.test:
typo
mysql-test/t/subselect.test:
only one error per statement, please
mysql-test/t/system_mysql_db_fix40123.test:
old timestamp(X) is no longer supported
mysql-test/t/system_mysql_db_fix50030.test:
old timestamp(X) is no longer supported
mysql-test/t/system_mysql_db_fix50117.test:
old timestamp(X) is no longer supported
mysql-test/t/type_blob.test:
old timestamp(X) is no longer supported
mysql-test/t/type_timestamp.test:
old timestamp(X) is no longer supported
mysys/my_getsystime.c:
functions to get the time with microsecond precision
mysys/my_init.c:
move the my_getsystime.c initialization code to my_getsystime.c
mysys/my_static.c:
no need to make these variables extern
mysys/my_static.h:
no need to make these variables extern
scripts/mysql_system_tables.sql:
old timestamp(X) is no longer supported
scripts/mysql_system_tables_fix.sql:
old timestamp(X) is no longer supported
scripts/mysqlhotcopy.sh:
old timestamp(X) is no longer supported
sql-common/my_time.c:
* call str_to_time from str_to_datetime, as appropriate
* date/time to string conversions take precision as an argument
* number_to_time()
* TIME_to_double()
* pack_time() and unpack_time()
sql/event_data_objects.cc:
cast is not needed
my_datetime_to_str() takes precision as an argument
sql/event_db_repository.cc:
avoid dangerous downcast (because the pointer is
not always Field_timestamp, see events_1.test)
sql/event_queue.cc:
avoid silly double-work for cond_wait
(having an endpoint of wait, subtract the current time to get the timeout,
and use set_timespec() macro to fill in struct timespec, by adding the current
time to the timeout)
sql/field.cc:
* remove virtual Field::get_time(), everyone should use only Field::get_date()
* remove lots of #ifdef WORDS_BIGENDIAN
* unified the warnings from Field_timestamp/datetime/time/date/newdate store methods
* Field_timestamp_hires, Field_datetime_hires, Field_time_hires
* Field_temporal
* make_truncated_value_warning and Field::set_datetime_warning use Lazy_string as an argument, removed char*/int/double variants
sql/field.h:
* remove virtual Field::get_time(), everyone should use only Field::get_date()
* remove lots of #ifdef WORDS_BIGENDIAN
* unified the warnings from Field_timestamp/datetime/time/date/newdate store methods
* Field_timestamp_hires, Field_datetime_hires, Field_time_hires
* Field_temporal
* make_truncated_value_warning and Field::set_datetime_warning use Lazy_string as an argument, removed char*/int/double variants
* removed Field::can_be_compared_as_longlong(). Use Field::cmp_type() == INT_RESULT instead
sql/filesort.cc:
TIME_RESULT, cmp_time()
sql/item.cc:
* numbers aren't quoted in EXPLAIN EXTENDED
* Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
* virtual Item::get_time() is gone
* Item_param::field_type() is set correctly
* Item_datetime, for a datetime constant
* time to anything is compared as a time
* Item_cache::print() prints the value is available
* bug fixed in Item_cache_int::val_str()
sql/item.h:
* Item::print_value(), to be used from Item_xxx::print() when needed
* Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
* virtual Item::get_time() is gone
* Item_datetime, for a datetime constant
* better default for cast_to_int_type()
* Item_cache objects now *always* have the field_type() set
sql/item_cmpfunc.cc:
* get_year_value, get_time_value are gone. get_datetime_value does it all
* get_value_a_func, get_value_b_func are gone
* can_compare_as_dates() is gone too, TIME_RESULT is used instead
* cmp_type() instead or result_type() when doing a comparison
* compare_datetime and compate_e_datetime in the comparator_matrix, is_nulls_eq is gone
* Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
sql/item_cmpfunc.h:
greatly simplified Arg_comparator
sql/item_create.cc:
* fix a bug in error messages in CAST
sql/item_func.cc:
Item::cmp_result() instead of Item::is_datetime() and Item::result_as_longlong()
mention all possibitiles in switch over Item_result values, or use default:
sql/item_row.h:
overwrite the default cmp_type() for Item_row,
as no MYSQL_TYPE_xxx value corresponds to ROW_RESULT
sql/item_timefunc.cc:
rewrite make_datetime to support precision argument
SEC_TO_TIME is real function, not integer.
many functions that returned temporal values had duplicate code in val_* methods,
some of them did not have get_date() which resulted in unnecessary date->str->date conversions.
Now they all are derived from Item_temporal_func and *only* provide get_date, not val* methods.
many fixes to set decimals (datetime precision) correctly.
sql/item_timefunc.h:
SEC_TO_TIME is real function, not integer.
many functions that returned temporal values had duplicate code in val_* methods,
some of them did not have get_date() which resulted in unnecessary date->str->date conversions.
Now they all are derived from Item_temporal_func and *only* provide get_date, not val* methods.
many fixes to set decimals (datetime precision) correctly.
sql/log_event.cc:
replication of NOW(6)
sql/log_event.h:
replication of NOW(6)
sql/mysql_priv.h:
Lazy_string class to pass a value (string, number, time) polymorphically down the stack.
make_truncated_value_warning() that uses it.
sql/mysqld.cc:
datetime in Arg_comparator::comparator_matrix
sql/opt_range.cc:
cleanup: don't disable warnings before calling save_in_field_no_warnings()
sql/protocol.cc:
Protocol::store(time) now takes the precision as an argument
sql/protocol.h:
Protocol::store(time) now takes the precision as an argument
sql/rpl_rli.cc:
small cleanup
sql/set_var.cc:
SET TIMESTAMP=double
sql/set_var.h:
@@TIMESTAMP is a double
sql/share/errmsg.txt:
precision and scale are unsigned
sql/slave.cc:
replication of NOW(6)
sql/sp_head.cc:
cleanup
sql/sql_class.cc:
support for NOW(6)
sql/sql_class.h:
support for NOW(6)
sql/sql_insert.cc:
support for NOW(6)
sql/sql_select.cc:
use item->cmp_type().
move a comment where it belongs
sql/sql_show.cc:
new column I_S.COLUMNS.DATETIME_PRECISION
sql/sql_yacc.yy:
TIME(X), DATETIME(X), cast, NOW(X), CURTIME(X), etc
sql/time.cc:
fix date_add_interval() to support MYSQL_TIMESTAMP_TIME argument
storage/myisam/ha_myisam.cc:
TIMESTAMP no longer carries ZEROFIELD flag, still we keep MYI file compatible.
strings/my_vsnprintf.c:
warnings
tests/mysql_client_test.c:
old timestamp(X) does not work anymore
datetime is no longer equal to time
1. Fixed the name of the table to proxies_priv
2. Fixed the column names to be of the form Capitalized_lowecarse instead of
Capitalized_Capitalized
3. Added Timestamp and Grantor columns
4. Added tests to plugin_auth to check the table structure
5. Updated the existing tests
1. Fixed the name of the table to proxies_priv
2. Fixed the column names to be of the form Capitalized_lowecarse instead of
Capitalized_Capitalized
3. Added Timestamp and Grantor columns
4. Added tests to plugin_auth to check the table structure
5. Updated the existing tests
sql_show.cc during rqg_info_schema test on Windows".
Ensure we do not access freed memory when filling
information_schema.views when one of the views
could not be properly opened.
mysql-test/r/information_schema.result:
Update results - a fix for Bug#56540.
mysql-test/t/information_schema.test:
Add a test case for Bug#56540
sql/sql_base.cc:
Push an error into the Diagnostics area
when we return an error.
This directs get_all_tables() to the execution
branch which doesn't involve 'process_table()'
when no table/view was opened.
sql/sql_show.cc:
Do not try to access underlying table fields
when opening of a view failed. The underlying
table is closed in that case, and accessing
its fields may lead to dereferencing a damaged
pointer.
sql_show.cc during rqg_info_schema test on Windows".
Ensure we do not access freed memory when filling
information_schema.views when one of the views
could not be properly opened.
- Changed to still use bcmp() in certain cases becasue
- Faster for short unaligneed strings than memcmp()
- Bettern when using valgrind
- Changed to use my_sprintf() instead of sprintf() to get higher portability for old systems
- Changed code to use MariaDB version of select->skip_record()
- Removed -%::SCCS/s.% from Makefile.am:s to remove automake warnings
