We pretended that TIMEDIFF() would always return positive results;
this gave strange results in comparisons of the TIMEDIFF(low,hi)<TIME(0)
type that rendered a negative result, but still gave false in comparison.
We also inadvertantly dropped the sign when converting times to
decimal.
CAST(time AS DECIMAL) handles signs of the times correctly.
TIMEDIFF() marked up as signed. Time/date comparison code switched to
signed for clarity.
mysql-test/r/func_sapdb.result:
show that time-related comparisons work with negative
time values now.
show that converting time to DECIMAL no longer drops sign.
mysql-test/t/func_sapdb.test:
show that time-related comparisons work with negative
time values now.
show that converting time to DECIMAL no longer drops sign.
sql/item_cmpfunc.cc:
signed returns
sql/item_cmpfunc.h:
signed now (time/date < > =)
sql/item_func.cc:
signed now
sql/item_timefunc.h:
Functions such as TIMEDIFF() return signed results!
The file-comments pretended we were doing that all along, anyway...
sql/my_decimal.cc:
heed sign when converting time to my_decimal;
times may actually be negative!
Needed for SELECT CAST(time('-73:42:12') AS DECIMAL);
sql/mysql_priv.h:
using signed for dates and times now
We pretended that TIMEDIFF() would always return positive results;
this gave strange results in comparisons of the TIMEDIFF(low,hi)<TIME(0)
type that rendered a negative result, but still gave false in comparison.
We also inadvertantly dropped the sign when converting times to
decimal.
CAST(time AS DECIMAL) handles signs of the times correctly.
TIMEDIFF() marked up as signed. Time/date comparison code switched to
signed for clarity.
Several system variables did not behave like system variables should do.
When trying to SET them or use them in SELECT, they were reported as
"unknown system variable". But they appeared in SHOW VARIABLES.
This has been fixed by removing the "fixed_vars" array of variables
and integrating the variables into the normal system variables chain.
All of these variables do now behave as read-only global-only
variables. Trying to SET them tells they are read-only, trying to
SELECT the session value tells they are global only. Selecting the
global value works. It delivers the same value as SHOW VARIABLES.
mysql-test/r/variables-notembedded.result:
Bug#28234 - global/session scope - documentation vs implementation
New test result.
mysql-test/r/variables.result:
Bug#28234 - global/session scope - documentation vs implementation
New test result.
mysql-test/t/variables-notembedded.test:
Bug#28234 - global/session scope - documentation vs implementation
Added a test for each moved variable that is not present in an
embedded server.
mysql-test/t/variables.test:
Bug#28234 - global/session scope - documentation vs implementation
Added a test for each moved variable that is also present in an
embedded server.
sql/item_func.cc:
Bug#28234 - global/session scope - documentation vs implementation
Added SHOW_BOOL to some Item_func_get_system_var methods.
sql/set_var.cc:
Bug#28234 - global/session scope - documentation vs implementation
Moved all variables from the "fixed_vars" array into the normal
system variables chain by using the new variable class sys_var_const.
Removed the fixed_show_vars array and its initialization in
enumerate_sys_vars().
Removed mysql_append_static_vars(), which added fixed_vars arrays
to the fixed_show_vars array.
sql/set_var.h:
Bug#28234 - global/session scope - documentation vs implementation
Added the new system variable class sys_var_const.
Removed declaration of mysql_append_static_vars().
sql/slave.cc:
Bug#28234 - global/session scope - documentation vs implementation
Moved the definition of show_slave_skip_errors() from sql_repl.cc
to here and renamed it to print_slave_skip_errors().
Changed print_slave_skip_errors() to create a static buffer with
a printable version of the error numbers set.
Added a call of print_slave_skip_errors() to init_slave_skip_errors().
sql/slave.h:
Bug#28234 - global/session scope - documentation vs implementation
Added declaration of slave_skip_error_names.
sql/sql_repl.cc:
Bug#28234 - global/session scope - documentation vs implementation
Moved all variables from the "fixed_vars" array into the normal
system variables chain by using the new variable class sys_var_const.
Moved the definition of show_slave_skip_errors() to slave.cc and
modified it to compute the string once at server initialization only.
Removed the call to mysql_append_static_vars().
Several system variables did not behave like system variables should do.
When trying to SET them or use them in SELECT, they were reported as
"unknown system variable". But they appeared in SHOW VARIABLES.
This has been fixed by removing the "fixed_vars" array of variables
and integrating the variables into the normal system variables chain.
All of these variables do now behave as read-only global-only
variables. Trying to SET them tells they are read-only, trying to
SELECT the session value tells they are global only. Selecting the
global value works. It delivers the same value as SHOW VARIABLES.
variable settings (rpl_sys)
Problem: under certain conditions (e.g. user variables usage in triggers)
accessing a user defined variable we may use a variables hash table that
belongs to already deleted thread. It happens if
thd= new THD;
has the same address as just deleted thd as we use
if (stored_thd == thd)
to check.
That may lead to unpredictable results, server crash etc.
Fix: use thread_id instead of thd address to distinguish threads.
Note: no simple and repeatable test case.
sql/item_func.cc:
Fix for bug#40770: Server Crash when running with triggers including
variable settings (rpl_sys)
- store and use thd->thread_id to distinguish threads instead of
thread address as it may be the same as just deleted thread had,
i.e. we may get (old_thd == new_thd) after
delete old_thd;
new_thd= new THD;
- set entry_thread_id only when we get a real entry, clear it
if the hash search fails.
sql/item_func.h:
Fix for bug#40770: Server Crash when running with triggers including
variable settings (rpl_sys)
- Item_func_set_user_var::entry_thread_id introduced.
variable settings (rpl_sys)
Problem: under certain conditions (e.g. user variables usage in triggers)
accessing a user defined variable we may use a variables hash table that
belongs to already deleted thread. It happens if
thd= new THD;
has the same address as just deleted thd as we use
if (stored_thd == thd)
to check.
That may lead to unpredictable results, server crash etc.
Fix: use thread_id instead of thd address to distinguish threads.
Note: no simple and repeatable test case.
Item_func_div didn't calculate the precision of the result properly.
The result of 5/0.0001 is 5000 so we have to add decimals of the divisor
to the planned precision.
per-file comments:
mysql-test/r/type_newdecimal.result
Bug#31616 div_precision_increment description looks wrong
test result fixed
mysql-test/t/type_newdecimal.test
Bug#31616 div_precision_increment description looks wrong
test case
sql/item_func.cc
Bug#31616 div_precision_increment description looks wrong
precision must be increased with args[1]->decimals parameter
Item_func_div didn't calculate the precision of the result properly.
The result of 5/0.0001 is 5000 so we have to add decimals of the divisor
to the planned precision.
per-file comments:
mysql-test/r/type_newdecimal.result
Bug#31616 div_precision_increment description looks wrong
test result fixed
mysql-test/t/type_newdecimal.test
Bug#31616 div_precision_increment description looks wrong
test case
sql/item_func.cc
Bug#31616 div_precision_increment description looks wrong
precision must be increased with args[1]->decimals parameter
With fix for bug 25951 index hints are ignored for fulltext
searches, as handling of fulltext indexes is different from
handling regular indexes. Meaning it is not possible to
implement true index hints support for fulltext indexes within
the scope of current fulltext architecture.
The problem is that prior to fix for bug 25951, some useful
index hints still could be given for boolean mode searches.
This patch implements special index hints support for fulltext
indexes with the following characteristics:
- all index hints are still ignored for NLQ mode searches -
it cannot work without an index;
- for 5.1 and up index hints FOR ORDER BY and FOR GROUP BY are
still ignored for fulltext indexes;
- boolean mode searches honor USE/FORCE/IGNORE INDEX hints;
- as opposed to index hints for regular indexes, index hints
for fulltext BOOLEAN mode searches affect the usage of the
index for the whole query.
mysql-test/r/fulltext.result:
A test case for BUG#38842.
mysql-test/t/fulltext.test:
A test case for BUG#38842.
sql/item_func.cc:
For boolean mode searches, which can work without fulltext
index, use keys_in_use_for_query bitmap instead of keys_in_use.
The effect is that boolean mode searches now honor index hints.
With fix for bug 25951 index hints are ignored for fulltext
searches, as handling of fulltext indexes is different from
handling regular indexes. Meaning it is not possible to
implement true index hints support for fulltext indexes within
the scope of current fulltext architecture.
The problem is that prior to fix for bug 25951, some useful
index hints still could be given for boolean mode searches.
This patch implements special index hints support for fulltext
indexes with the following characteristics:
- all index hints are still ignored for NLQ mode searches -
it cannot work without an index;
- for 5.1 and up index hints FOR ORDER BY and FOR GROUP BY are
still ignored for fulltext indexes;
- boolean mode searches honor USE/FORCE/IGNORE INDEX hints;
- as opposed to index hints for regular indexes, index hints
for fulltext BOOLEAN mode searches affect the usage of the
index for the whole query.
IS NULL was not checking the correct row in a HAVING context.
At the first row of a new group (where the HAVING clause is evaluated)
the column and SELECT list references in the HAVING clause should
refer to the last row of the previous group and not to the current one.
This was not done for IS NULL, because it was using Item::is_null() doesn't
have a Item_is_null_result() counterpart to access the data from the
last row of the previous group. Note that all the Item::val_xxx() functions
(e.g. Item::val_int()) have their _result counterparts (e.g. Item::val_int_result()).
Fixed by implementing a is_null_result() (similarly to int_result()) and
calling this instead of is_null() column and SELECT list references inside
the HAVING clause.
mysql-test/r/having.result:
Bug #38637: test case
mysql-test/t/having.test:
Bug #38637: test case
sql/item.cc:
Bug #38637: implement Item::is_null_result() and call it
from Item_ref and Item_field as appropriate.
sql/item.h:
Bug #38637: implement Item::is_null_result() and call it
from Item_ref and Item_field as appropriate.
sql/item_func.cc:
Bug #38637: implement Item::is_null_result() and call it
from Item_ref and Item_field as appropriate.
sql/item_func.h:
Bug #38637: implement Item::is_null_result() and call it
from Item_ref and Item_field as appropriate.
IS NULL was not checking the correct row in a HAVING context.
At the first row of a new group (where the HAVING clause is evaluated)
the column and SELECT list references in the HAVING clause should
refer to the last row of the previous group and not to the current one.
This was not done for IS NULL, because it was using Item::is_null() doesn't
have a Item_is_null_result() counterpart to access the data from the
last row of the previous group. Note that all the Item::val_xxx() functions
(e.g. Item::val_int()) have their _result counterparts (e.g. Item::val_int_result()).
Fixed by implementing a is_null_result() (similarly to int_result()) and
calling this instead of is_null() column and SELECT list references inside
the HAVING clause.
Fixed the handling of system variable retrieval
in prepared statements : added a cleanup method
that clears up the cache and restores the
original scope of the variable (which is overwritten
at fix_fields()).
sql/item_func.cc:
ug #32124:
- preserve the requested variable scope
- clean up the cache and restore the variable
scope for prepared statements.
sql/item_func.h:
Bug #32124: preserve the requested variable scope
Fixed the handling of system variable retrieval
in prepared statements : added a cleanup method
that clears up the cache and restores the
original scope of the variable (which is overwritten
at fix_fields()).
The code to get read the value of a system variable was extracting its value
on PREPARE stage and was substituting the value (as a constant) into the parse tree.
Note that this must be a reversible transformation, i.e. it must be reversed before
each re-execution.
Unfortunately this cannot be reliably done using the current code, because there are
other non-reversible source tree transformations that can interfere with this
reversible transformation.
Fixed by not resolving the value at PREPARE, but at EXECUTE (as the rest of the
functions operate). Added a cache of the value (so that it's constant throughout
the execution of the query). Note that the cache also caches NULL values.
Updated an obsolete related test suite (variables-big) and the code to test the
result type of system variables (as per bug 74).
mysql-test/extra/rpl_tests/rpl_insert_id.test:
Bug #32124: removed ambiguous testcase
mysql-test/r/innodb_data_home_dir_basic.result:
Bug #32124: fixed wrong test case
mysql-test/r/innodb_flush_method_basic.result:
Bug #32124: fixed wrong test case
mysql-test/r/ps_11bugs.result:
Bug #32124: test case
mysql-test/r/ssl_capath_basic.result:
Bug #32124: fixed wrong test case
mysql-test/r/ssl_cipher_basic.result:
Bug #32124: fixed wrong test case
mysql-test/r/variables.result:
Bug #32124: system vars are shown as such in EXPLAIN EXTENDED, not as constants.
mysql-test/suite/rpl/r/rpl_insert_id.result:
Bug #32124: removed ambiguous testcase
mysql-test/t/ps_11bugs.test:
Bug #32124: test case
sql/item.cc:
Bug #32124: placed the code to convert string to longlong or double
to a function (so that it can be reused)
sql/item.h:
Bug #32124: placed the code to convert string to longlong or double
to a function (so that it can be reused)
sql/item_func.cc:
Bug #32124: moved the evaluation of system variables at runtime (val_xxx).
sql/item_func.h:
Bug #32124: moved the evaluation of system variables at runtime (val_xxx).
sql/set_var.cc:
Bug #32124: removed the code that calculated the system variable's value
at PREPARE
sql/set_var.h:
Bug #32124: removed the code that calculated the system variable's value
at PREPARE
tests/mysql_client_test.c:
Bug #32124 : removed the reading of the system variable, because its max
length is depended on the system charset and client charset and can't be
easily calculated.
The code to get read the value of a system variable was extracting its value
on PREPARE stage and was substituting the value (as a constant) into the parse tree.
Note that this must be a reversible transformation, i.e. it must be reversed before
each re-execution.
Unfortunately this cannot be reliably done using the current code, because there are
other non-reversible source tree transformations that can interfere with this
reversible transformation.
Fixed by not resolving the value at PREPARE, but at EXECUTE (as the rest of the
functions operate). Added a cache of the value (so that it's constant throughout
the execution of the query). Note that the cache also caches NULL values.
Updated an obsolete related test suite (variables-big) and the code to test the
result type of system variables (as per bug 74).
columns data types
The "SELECT @lastId, @lastId := Id FROM t" query returns
different result sets depending on the type of the Id column
(INT or BIGINT).
Note: this fix doesn't cover the case when a select query
references an user variable and stored function that
updates a value of that variable, in this case a result
is indeterminate.
The server uses incorrect assumption about a constantness of
an user variable value as a select list item:
The server caches a last query number where that variable
was changed and compares this number with a current query
number. If these numbers are different, the server guesses,
that the variable is not updating in the current query, so
a respective select list item is a constant. However, in some
common cases the server updates cached query number too late.
The server has been modified to memorize user variable
assignments during the parse phase to take them into account
on the next (query preparation) phase independently of the
order of user variable references/assignments in a select
item list.
mysql-test/r/user_var.result:
Added test case for bug #26020.
mysql-test/t/user_var.test:
Added test case for bug #26020.
sql/item_func.cc:
An update of entry and update_query_id variables has been
moved from Item_func_set_user_var::fix_fields() to a separate
method, Item_func_set_user_var::set_entry().
sql/item_func.h:
1. The Item_func_set_user_var::set_entry() method has been
added to update Item_func_set_user_var::entry.
2. The Item_func_set_user_var::entry_thd field has beend
added to update Item_func_set_user_var::entry only when
needed.
sql/sql_base.cc:
Fix: setup_fiedls() calls Item_func_set_user_var::set_entry()
for all items from the thd->lex->set_var_list before the first
call of ::fix_fields().
sql/sql_lex.cc:
The lex_start function has been modified to reset
the st_lex::set_var_list list.
sql/sql_lex.h:
New st_lex::set_var_list field has been added to
memorize all user variable assignments in the current
select query.
sql/sql_yacc.yy:
The variable_aux rule has been modified to memorize
in-query user variable assignments in the
st_lex::set_var_list list.
columns data types
The "SELECT @lastId, @lastId := Id FROM t" query returns
different result sets depending on the type of the Id column
(INT or BIGINT).
Note: this fix doesn't cover the case when a select query
references an user variable and stored function that
updates a value of that variable, in this case a result
is indeterminate.
The server uses incorrect assumption about a constantness of
an user variable value as a select list item:
The server caches a last query number where that variable
was changed and compares this number with a current query
number. If these numbers are different, the server guesses,
that the variable is not updating in the current query, so
a respective select list item is a constant. However, in some
common cases the server updates cached query number too late.
The server has been modified to memorize user variable
assignments during the parse phase to take them into account
on the next (query preparation) phase independently of the
order of user variable references/assignments in a select
item list.
min() and max() functions are implemented in MySQL as macros.
This means that max(a,b) is expanded to: ((a) > (b) ? (a) : (b))
Note how 'a' is quoted two times.
Now imagine 'a' is a recursive function call that's several 10s of levels deep.
And the recursive function does max() with a function arg as well to dive into
recursion.
This means that simple function call can take most of the clock time.
Identified and fixed several such calls to max()/min() : including the IF()
sql function implementation.
mysql-test/r/func_if.result:
Bug#37662 test case
mysql-test/t/func_if.test:
Bug#37662 test case
sql/item.cc:
Bug#37662 don't call expensive functions as arguments to min/max
sql/item_cmpfunc.cc:
Bug#37662 don't call expensive functions as arguments to min/max
sql/item_func.cc:
Bug#37662 don't call expensive functions as arguments to min/max
min() and max() functions are implemented in MySQL as macros.
This means that max(a,b) is expanded to: ((a) > (b) ? (a) : (b))
Note how 'a' is quoted two times.
Now imagine 'a' is a recursive function call that's several 10s of levels deep.
And the recursive function does max() with a function arg as well to dive into
recursion.
This means that simple function call can take most of the clock time.
Identified and fixed several such calls to max()/min() : including the IF()
sql function implementation.
