causes incorrect duplicate entries
Keys for BTREE indexes on ENUM and SET columns of MEMORY tables
with character set UTF8 were computed incorrectly. Many
different column values got the same key value.
Apart of possible performance problems, it made unique indexes
of this type unusable because it rejected many different
values as duplicates.
The problem was that multibyte character detection was tried
on the internal numeric column value. Many values were not
identified as characters. Their key value became blank filled.
Thanks to Alexander Barkov and Ramil Kalimullin for the patch,
which sets the character set of ENUM and SET key segments to
the pseudo binary character set.
Accessing a file that is bigger than 2G may report that read/write operation
failed. This may affect anything that uses my_pread/my_pwrite functions, e.g.
MyISAM, ARCHIVE, binary log.
For MyISAM INSERT may report that table is crashed when writing to a table
that is bigger than 2G.
This is fixed by using proper offset type in my_pread/my_pwrite functions on
systems that do not have native pread/pwrite calls.
Affects systems that do not have native pread/pwrite calls, e.g. Windows.
No test case for this fix, since it requires huge table.
* Modified Federated memory allocation to use MEM_ROOT
* Modified sql_servers and federated to allocate share connection
parameters to use MEM_ROOT
* Modified Federated to allow tablename in addition to server name
* Implicit flushing of tables using altered/dropped server name
* Added tests to prove new functionality works
Contributors to this patch: Patrick Galbraith, Antony Curtis
"Concurrent ALTER/CREATE SERVER can lead to deadlock"
Deadlock caused by inconsistant use of mutexes in sql_server.cc
One mutex has been removed to resolve deadlock.
Many functions were made private which should not be exported.
Unused variables and function removed.
another user.
When the DEFINER clause isn't specified in the ALTER statement then it's loaded
from the view definition. If the definer differs from the current user then
the error is thrown because only a super-user can set other users as a definers.
Now if the DEFINER clause is omitted in the ALTER VIEW statement then the
definer from the original view is used without check.
in index search MySQL was not explicitly
suppressing warnings. And if the context
happens to enable warnings (e.g. INSERT ..
SELECT) the warnings resulting from converting
the data the key is compared to are
reported to the client.
Fixed by suppressing warnings when converting
the data to the same type as the key parts.
The problem in this bug is when we create temporary tables. When
temporary tables are created for unions, there is some
inferrence being carried out regarding the type of the column.
Whenever this column type is inferred to be REAL (i.e. FLOAT or
DOUBLE), MySQL will always try to maintain exact precision, and
if that is not possible (there are hardware limits, since FLOAT
and DOUBLE are stored as approximate values) will switch to
using approximate values. The problem here is that at this point
the information about number of significant digits is not
available. Furthermore, the number of significant digits should
be increased for the AVG function, however, this was not properly
handled. There are 4 parts to the problem:
#1: DOUBLE and FLOAT fields don't display their proper display
lengths in max_display_length(). This is hard-coded as 53 for
DOUBLE and 24 for FLOAT. Now changed to instead return the
field_length.
#2: Type holders for temporary tables do not preserve the
max_length of the Item's from which they are created, and is
instead reverted to the 53 and 24 from above. This causes
*all* fields to get non-fixed significant digits.
#3: AVG function does not update max_length (display length)
when updating number of decimals.
#4: The function that switches to non-fixed number of
significant digits should use DBL_DIG + 2 or FLT_DIG + 2 as
cut-off values (Since fixed precision does not use the 'e'
notation)
Of these points, #1 is the controversial one, but this
change is preferred and has been cleared with Monty. The
function causes quite a few unit tests to blow up and they had
to b changed, but each one is annotated and motivated. We
frequently see the magical 53 and 24 give way to more relevant
numbers.
