A better fix for bug#10025.
Fixed test case plus added new tests.
After fixing Bug#20208 "Blobs greater than 8K are being truncated to 8K"
the fix to bug#10025 "Misleading error with COLLATE mediumtext and UNION"
became more accurate. Earlier mediumtext got converted to longtext,
although mediumtext was enough to contain the results. Now it converts
correctly to mediumtext, if the length does not exceed that and if none
of the original fields were type longtext.
Type longtext still converts correctly to type longtext, as the extra
tests prove.
- Make the range-et-al optimizer produce E(#table records after table
condition is applied),
- Make the join optimizer use this value,
- Add "filtered" column to EXPLAIN EXTENDED to show
fraction of records left after table condition is applied
- Adjust test results, add comments
The Item::tmp_table_field_from_field_type() function creates Field_datetime
object instead of Field_timestamp object for timestamp field thus always
changing data type is a tmp table is used.
The Field_blob object constructor which is used in the
Item::tmp_table_field_from_field_type() is always setting packlength field of
newly created blob to 4. This leads to changing fields data type for example
from the blob to the longblob if a temporary table is used.
The Item::make_string_field() function always converts Field_string objects
to Field_varstring objects. This leads to changing data type from the
char/binary to varchar/varbinary.
Added appropriate Field_timestamp object constructor for using in the
Item::tmp_table_field_from_field_type() function.
Added Field_blob object constructor which sets pack length according to
max_length argument.
The Item::tmp_table_field_from_field_type() function now creates
Field_timestamp object for a timestamp field.
The Item_type_holder::display_length() now returns correct NULL length NULL
length.
The Item::make_string_field() function now doesn't change Field_string to
Field_varstring in the case of Item_type_holder.
The Item::tmp_table_field_from_field_type() function now uses the Field_blob
constructor which sets packlength according to max_length.
This was only demonstrated by the use of PASSWORD(), it was not related to
that function at all. The calculation of the size of a field in the results
of a UNION did not take into account the possible growth of a string field
when being converted to the aggregated character set.
SHOW STATUS are not anymore put in slow query log because of no index usage.
Implemntation done by removing orig_sql_command and moving logic of SHOW STATUS to mysql_excute_command()
This simplifies code and allows us to remove some if statements all over the code.
Upgraded uc_update_queries[] to sql_command_flags and added more bitmaps to better categorize commands.
This allowed some overall simplifaction when testing sql_command.
Fixes bugs:
Bug#10210: running SHOW STATUS increments counters it shouldn't
Bug#19764: SHOW commands end up in the slow log as table scans
resulted in a wrong error message.
The nest_level counter indicates the depth of nesting for a subselect. It is
needed to properly resolve aggregate functions in nested subselects. Obviously
it shouldn't be incremented for UNION parts because they have the same level of
nesting. This counter was incremented by 1 in the mysql_new_select() function
for any new select and wasn't decremented for UNION parts. This resulted in
wrongly reported error messages.
Now the nest_level counter is decremented by 1 for any union part.
union.result, union.test:
Adding test case.
item.cc:
Allow safe character set conversion in UNION
- string constant to column's charset
- to unicode
Thus, UNION now works the same with CONCAT (and other string functions)
in respect of aggregating arguments with different character sets.
"Process NATURAL and USING joins according to SQL:2003".
* Some of the main problems fixed by the patch:
- in "select *" queries the * expanded correctly according to
ANSI for arbitrary natural/using joins
- natural/using joins are correctly transformed into JOIN ... ON
for any number/nesting of the joins.
- column references are correctly resolved against natural joins
of any nesting and combined with arbitrary other joins.
* This patch also contains a fix for name resolution of items
inside the ON condition of JOIN ... ON - in this case items must
be resolved only against the JOIN operands. To support such
'local' name resolution, the patch introduces a stack of
name resolution contexts used at parse time.
NOTICE:
- This patch is not complete in the sense that
- there are 2 test cases that still do not pass -
one in join.test, one in select.test. Both are marked
with a comment "TODO: WL#2486".
- it does not include a new test specific for the task
Results for the above test case
union.test:
A test case for bug #10032 involving UNION's and ORDER BY clause
sql_yacc.yy:
Fix for a bug #10032 involving a parser bug with UNION's and ORDER BY
fixing tests accordingly
item.cc:
Allow mixing non-binary collation and binary collation
even if coercibility is the same.
For easier 4.0 -> 4.1 migrating.
