Problem: in mixed and statement mode, a query that refers to a
system variable will use the slave's value when replayed on
slave. So if the value of a system variable is inserted into a
table, the slave will differ from the master.
Fix: mark statements that refer to a system variable as "unsafe",
meaning they will be replicated by row in mixed mode and produce a warning
in statement mode. There are some exceptions: some variables are actually
replicated. Those should *not* be marked as unsafe.
BUG#34732: mysqlbinlog does not print default values for auto_increment variables
Problem: mysqlbinlog does not print default values for some variables,
including auto_increment_increment and others. So if a client executing
the output of mysqlbinlog has different default values, replication will
be wrong.
Fix: Always print default values for all variables that are replicated.
I need to fix the two bugs at the same time, because the test cases would
fail if I only fixed one of them.
NAME_CONST('whatever', -1) * MAX(whatever) bombed since -1 was
not seen as constant, but as FUNCTION_UNARY_MINUS(constant)
while we are at the same time pretending it was a basic const
item. This confused the aggregate handlers in exciting ways.
We now make NAME_CONST() behave more consistently.
between 5.0 and 5.1.
The problem was that in the patch for Bug#11986 it was decided
to store original query in UTF8 encoding for the INFORMATION_SCHEMA.
This approach however turned out to be quite difficult to implement
properly. The main problem is to preserve the same IS-output after
dump/restore.
So, the fix is to rollback to the previous functionality, but also
to fix it to support multi-character-set-queries properly. The idea
is to generate INFORMATION_SCHEMA-query from the item-tree after
parsing view declaration. The IS-query should:
- be completely in UTF8;
- not contain character set introducers.
For more information, see WL4052.
floating point numbers
Some math functions did not check if the result is a valid number
(i.e. neither of +-inf or nan).
Fixed by validating the result where necessary and returning NULL in
case of invalid result.
There's currently no way of knowing the determinicity of an UDF.
And the optimizer and the sequence() UDFs were making wrong
assumptions about what the is_const member means.
Plus there was no implementation of update_system_tables()
causing the optimizer to overwrite the information returned by
the <udf>_init function.
Fixed by equating the assumptions about the semantics of
is_const and providing a implementation of update_used_tables().
Added a TODO item for the UDF API change needed to make a better
implementation.
Problem: setting Item_func_rollup_const::null_value property to argument's null_value
before (without) the argument evaluation may result in a crash due to wrong null_value.
Fix: use is_null() to set Item_func_rollup_const::null_value instead as it evaluates
the argument if necessary and returns a proper value.
There are two problems with ROUND(X, D) on an exact numeric
(DECIMAL, NUMERIC type) field of a table:
1) The implementation of the ROUND function would change the number of decimal
places regardless of the value decided upon in fix_length_and_dec. When the
number of decimal places is not constant, this would cause an inconsistent
state where the number of digits was less than the number of decimal places,
which crashes filesort.
Fixed by not allowing the ROUND operation to add any more decimal places than
was decided in fix_length_and_dec.
2) fix_length_and_dec would allow the number of decimals to be greater than
the maximium configured value for constant values of D. This led to the same
crash as in (1).
Fixed by not allowing the above in fix_length_and_dec.
when used in a VIEW.
The problem was that wrong function (create_tmp_from_item())
was used to create a temporary field for Item_func_sp.
The fix is to use create_tmp_from_field().
The Item_func_rollup_const class is used for wrapping constants to avoid
wrong result for ROLLUP queries with DISTINCT and a constant in the select
list. This class is also used to wrap up a NULL constant but its null_value
wasn't set accordingly. This led to a server crash.
Now the null_value of an object of the Item_func_rollup_const class is set
by its fix_length_and_dec member function.
type of the result.
There are several functions that accept parameters of different types.
The result field type of such functions was determined based on
the aggregated result type of its arguments. As the DATE and the DATETIME
types are represented by the STRING type, the result field type
of the affected functions was always STRING for DATE/DATETIME arguments.
The affected functions are COALESCE, IF, IFNULL, CASE, LEAST/GREATEST, CASE.
Now the affected functions aggregate the field types of their arguments rather
than their result types and return the result of aggregation as their result
field type.
The cached_field_type member variable is added to the number of classes to
hold the aggregated result field type.
The str_to_date() function's result field type now defaults to the
MYSQL_TYPE_DATETIME.
The agg_field_type() function is added. It aggregates field types with help
of the Field::field_type_merge() function.
The create_table_from_items() function now uses the
item->tmp_table_field_from_field_type() function to get the proper field
when the item is a function with a STRING result type.
Optimization of queries with DETERMINISTIC functions in the
WHERE clause was not effective: sequential scan was always
used.
Now a SF with the DETERMINISTIC flags is treated as constant
when it's arguments are constants (or a SF doesn't has arguments).
This is an additional fix.
Item::val_xxx methods are supposed to use original data source and
Item::val_xxx_result methods to use the item's result field. But for the
Item_func_set_user_var class val_xxx_result methods were mapped to val_xxx
methods. This leads, in particular, to producing bad sort keys and thus
wrong order of the result set of queries with group by/order by clauses.
The set of val_xxx_result methods is added to the Item_func_set_user_var
class. It's the same as the val_xxx set of method but uses the result_field
to return a value.
The end_update() function uses the Item::save_org_in_field() function to
save original values of items into the group buffer. But for the
Item_func_set_user_var this method was mapped to the save_in_field method.
The latter function wrongly decides to use the result_field. This leads to
saving incorrect value in the grouping buffer and wrong result of the whole
query.
The can_use_result_field argument of the bool type is added to the
Item_func_set_user_var::save_in_field() function. If it is set to FALSE
then the item's result field won't be used. Otherwise it will be detected
whether the result field will be used (old behaviour).
Two wrapping functions for the function above are added to the
Item_func_set_user_var class:
the save_in_field(Field *field, bool no_conversions) - it calls the above
function with the can_use_result_field set to TRUE.
the save_org_in_field(Field *field) - same, but the can_use_result_field
is set to FALSE.
- Adding variable m_cached_result_type to keep the variable type consistent
during the execution of a statement.
- Before each result set is returned to the client the description of each
column is sent as meta data.
Previously the result type for a column could change if the hash variable
entry changed between statements. This caused the result set of the query
to alternate column types in certain cases which is not supported by MySQL
client-server protocol. Example:
Previously this sequence:
SET @a:=1;
SELECT @a:="text", @a;
would return "text", "text";
After the change the SELECT returns "text", 0
The reson for this is that previously the result set from 'SELECT @a;'
would always be of the type STRING, whereas now the type of the variable
is taken from the last SET statement. However, 'SELECT @a:="text"' will
return type of STRING since the right side of the assignment is used.
Made year 2000 handling more uniform
Removed year 2000 handling out from calc_days()
The above removes some bugs in date/datetimes with year between 0 and 200
Now we get a note when we insert a datetime value into a date column
For default values to CREATE, don't give errors for warning level NOTE
Fixed some compiler failures
Added library ws2_32 for windows compilation (needed if we want to compile with IOCP support)
Removed duplicate typedef TIME and replaced it with MYSQL_TIME
Better (more complete) fix for: Bug#21103 "DATE column not compared as DATE"
Fixed properly Bug#18997 "DATE_ADD and DATE_SUB perform year2K autoconversion magic on 4-digit year value"
Fixed Bug#23093 "Implicit conversion of 9912101 to date does not match cast(9912101 as date)"
