Problem:
Field_set::val_str in case of an empty SET value
returned a String with str_length==0 and Ptr==0,
which is not expected by some pieces of the code.
Fix:
Returning an empty string with str_length==0 and Ptr=="",
like Field_enum does.
The test case must insert all the records using a single transaction. Otherwise the test
case takes more than 15 minutes and will time out in pb2 and mtr.
AND SAVEPOINT.
The bug was introduced by the patch for bug#11766752. This patch sets too
strong condition on XA state for SAVEPOINT statement that disallows its
execution during XA transaction. But since the statement SAVEPOINT doesn't
imply implicit commit we can allow its handling during XA transaction.
The patch explicitly check for transaction state against states XA_NOTR
and XA_ACTIVE for which the handling of statement SAVEPOINT for XA
transaction is allowed.
The table contains one time value: '00:00:32'
This value is converted to timestamp by a subquery.
In convert_constant_item we call (*item)->is_null()
which triggers execution of the Item_singlerow_subselect subquery,
and the string "0000-00-00 00:00:32" is cached
by Item_cache_datetime.
We continue execution and call update_null_value, which calls val_int()
on the cached item, which converts the time value to ((longlong) 32)
Then we continue to do (*item)->save_in_field()
which ends up in Item_cache_datetime::val_str() which fails,
since (32 < 101) in number_to_datetime, and val_str() returns NULL.
Item_singlerow_subselect::val_str isnt prepared for this:
if exec() succeeds, and return !null_value, then val_str()
*must* succeed.
Solution: refuse to cache strings like "0000-00-00 00:00:32"
in Item_cache_datetime::cache_value, and return NULL instead.
This is similar to the solution for
Bug#11766860 - 60085: CRASH IN ITEM::SAVE_IN_FIELD() WITH TIME DATA TYPE
This patch is for 5.5 only.
The issue is not present after WL#946, since a time value
will be converted to a proper timestamp, with the current date
rather than "0000-00-00"
We are trying to sort a lot of text/blob fields,
so the buffer is indeed too small.
Memory available = thd->variables.sortbuff_size = 262144
min_sort_memory = param.sort_length*MERGEBUFF2 = 292245
So the decision to abort the query is correct.
filesort() calls my_error(), the error is reported.
But, since we have DELETE IGNORE ... the error is converted to a warning by
THD::raise_condition
filesort currently expects an error to be recorded in the THD diagnostics
area.
If we lift this restriction (remove the assert) we end up in the familiar
void Protocol::end_statement()
default:
DBUG_ASSERT(0);
The solution seems to be to call my_error(ME_FATALERROR) in filesort,
so that the error is propagated as an error rather than a warning.
ENOUGH - CONCAT() HACKS. ALSO WRONG
ERROR MESSAGE WHILE TRYING TO CREATE
A VIEW ON A NON EXISTING DATABASE
PROBLEM:
The first part of the problem is concluded as not a
bug, as 'concat' is not a reserved word and it is
completely valid to create a view with the name
'concat'.
The second issue is, while trying to create a view on
a non existing database, we are not giving a proper error
message.
FIX:
We have added a check for the database existence while
trying to create a view. This check would give an error
as 'unknown database' when the database does not exist.
This patch is a backport of the patch for Bug#13601606
BUG#64503: mysql frequently ignores --relay-log-space-limit
When the SQL thread goes to sleep, waiting for more events, it sets
the flag ignore_log_space_limit to true. This gives the IO thread a
chance to queue some more events and ultimately the SQL thread will be
able to purge the log once it is rotated. By then the SQL thread
resets the ignore_log_space_limit to false. However, between the time
the SQL thread has set the ignore flag and the time it resets it, the
IO thread will be queuing events in the relay log, possibly going way
over the limit.
This patch makes the IO and SQL thread to synchronize when they reach
the space limit and only ask for one event at a time. Thus the SQL
thread sets ignore_log_space_limit flag and the IO thread resets it to
false everytime it processes one more event. In addition, everytime
the SQL thread processes the next event, and the limit has been
reached, it checks if the IO thread should rotate. If it should, it
instructs the IO thread to rotate, giving the SQL thread a chance to
purge the logs (freeing space). Finally, this patch removes the
resetting of the ignore_log_space_limit flag from purge_first_log,
because this is now reset by the IO thread every time it processes the
next event when the limit has been reached.
If the SQL thread is in a transaction, it cannot purge so, there is no
point in asking the IO thread to rotate. The only thing it can do is
to ask for more events until the transaction is over (then it can ask
the IO to rotate and purge the log right away). Otherwise, there would
be a deadlock (SQL would not be able to purge and IO thread would not
be able to queue events so that the SQL would finish the transaction).
Problem: Grouping results by VALUES(alias for string literal) causes
the server to crash.
Item_insert_values is not constructed to handle other types of
arguments than field and reference to field. In this case, the
argument is an Item_string, and this causes
Item_insert_values::fix_fields() to crash.
Fix: Issue an error message when the argument to Item_insert_values is
not a field or a reference to a field.
This is slightly in breach with documentation, which states that
VALUES should return NULL, but the error message is only issued in
cases where the server otherwise would crash, so there is no change in
behavior for queries that already work. Future versions will restrict
syntax so that using VALUES in this way is illegal.
USER VARIABLE = CRASH
Moved the preparation of the variables that receive the output from
SELECT INTO from execution time (JOIN:execute) to compile time
(JOIN::prepare). This ensures that if the same variable is used in the
SELECT part of SELECT INTO it will be properly marked as non-const
for this query.
Test case added.
Used proper fast iterator.
truncating, inserting the same set of rows. When a table is
re-created with the same set of rows, the data file size must
not grow.
rb:968
Approved by Marko.
A defect in the subquery substitution code may lead to a server crash:
setting substitution's name should be followed by setting its length
(to keep them in sync).
Problem:
lack of incoming geometry data validation may
lead to a server crash when ISCLOSED() function called.
Solution:
necessary incoming data check added.
There are two threads. In one thread, dml operation is going on
involving cascaded update operation. In another thread, alter
table add foreign key constraint is happening. Under these
circumstances, it is possible for the dml thread to access a
dict_foreign_t object that has been freed by the ddl thread.
The debug sync test case provides the sequence of operations.
Without fix, the test case will crash the server (because of
newly added assert). With fix, the alter table stmt will return
an error message.
Backporting the fix from MySQL 5.5 to 5.1
rb:961
rb:947
Analysis:
========================
sql_mode "NO_BACKSLASH_ESCAPES": When user want to use backslash as character input,
instead of escape character in a string literal then sql_mode can be set to
"NO_BACKSLASH_ESCAPES". With this mode enabled, backslash becomes an ordinary
character like any other.
SQL_MODE set applies to the current client session. And while creating the stored
procedure, MySQL stores the current sql_mode and always executes the stored
procedure in sql_mode stored with the Procedure, regardless of the server SQL
mode in effect when the routine is invoked.
In the scenario (for which bug is reported), the routine is created with
sql_mode=NO_BACKSLASH_ESCAPES. And routine is executed with the invoker sql_mode
is "" (NOT SET) by executing statement "call testp('Axel\'s')".
Since invoker sql_mode is "" (NOT_SET), the '\' in 'Axel\'s'(argument to function)
is considered as escape character and column "a" (of table "t1") values are
updated with "Axel's". The binary log generated for above update operation is as below,
set sql_mode=XXXXXX (for no_backslash_escapes)
update test.t1 set a= NAME_CONST('var',_latin1'Axel\'s' COLLATE 'latin1_swedish_ci');
While logging stored procedure statements, the local variables (params) used in
statements are replaced with the NAME_CONST(var_name, var_value) (Internal function)
(http://dev.mysql.com/doc/refman/5.6/en/miscellaneous-functions.html#function_name-const)
On slave, these logs are applied. NAME_CONST is parsed to get the variable and its
value. Since, stored procedure is created with sql_mode="NO_BACKSLASH_ESCAPES", the sql_mode
is also logged in. So that at slave this sql_mode is set before executing the statements
of routine. So at slave, sql_mode is set to "NO_BACKSLASH_ESCAPES" and then while
parsing NAME_CONST of string variable, '\' is considered as NON ESCAPE character
and parsing reported error for "'" (as we have only one "'" no backslash).
At slave, parsing was proper with sql_mode "NO_BACKSLASH_ESCAPES".
But above error reported while writing bin log, "'" (of Axel's) is escaped with
"\" character. Actually, all special characters (n, r, ', ", \, 0...) are escaped
while writing NAME_CONST for string variable(param, local variable) in bin log
irrespective of "NO_BACKSLASH_ESCAPES" sql_mode. So, basically, the problem is
that logging string parameter does not take into account sql_mode value.
Fix:
========================
So when sql_mode is set to "NO_BACKSLASH_ESCAPES", escaping characters as
(n, r, ', ", \, 0...) should be avoided. To do so, added a check to not to
escape such characters while writing NAME_CONST for string variables in bin
log.
And when sql_mode is set to NO_BACKSLASH_ESCAPES, quote character "'" is
represented as ''.
http://dev.mysql.com/doc/refman/5.6/en/string-literals.html (There are several
ways to include quote characters within a string: )
Analysis:
========================
sql_mode "NO_BACKSLASH_ESCAPES": When user want to use backslash as character input,
instead of escape character in a string literal then sql_mode can be set to
"NO_BACKSLASH_ESCAPES". With this mode enabled, backslash becomes an ordinary
character like any other.
SQL_MODE set applies to the current client session. And while creating the stored
procedure, MySQL stores the current sql_mode and always executes the stored
procedure in sql_mode stored with the Procedure, regardless of the server SQL
mode in effect when the routine is invoked.
In the scenario (for which bug is reported), the routine is created with
sql_mode=NO_BACKSLASH_ESCAPES. And routine is executed with the invoker sql_mode
is "" (NOT SET) by executing statement "call testp('Axel\'s')".
Since invoker sql_mode is "" (NOT_SET), the '\' in 'Axel\'s'(argument to function)
is considered as escape character and column "a" (of table "t1") values are
updated with "Axel's". The binary log generated for above update operation is as below,
set sql_mode=XXXXXX (for no_backslash_escapes)
update test.t1 set a= NAME_CONST('var',_latin1'Axel\'s' COLLATE 'latin1_swedish_ci');
While logging stored procedure statements, the local variables (params) used in
statements are replaced with the NAME_CONST(var_name, var_value) (Internal function)
(http://dev.mysql.com/doc/refman/5.6/en/miscellaneous-functions.html#function_name-const)
On slave, these logs are applied. NAME_CONST is parsed to get the variable and its
value. Since, stored procedure is created with sql_mode="NO_BACKSLASH_ESCAPES", the sql_mode
is also logged in. So that at slave this sql_mode is set before executing the statements
of routine. So at slave, sql_mode is set to "NO_BACKSLASH_ESCAPES" and then while
parsing NAME_CONST of string variable, '\' is considered as NON ESCAPE character
and parsing reported error for "'" (as we have only one "'" no backslash).
At slave, parsing was proper with sql_mode "NO_BACKSLASH_ESCAPES".
But above error reported while writing bin log, "'" (of Axel's) is escaped with
"\" character. Actually, all special characters (n, r, ', ", \, 0...) are escaped
while writing NAME_CONST for string variable(param, local variable) in bin log
Airrespective of "NO_BACKSLASH_ESCAPES" sql_mode. So, basically, the problem is
that logging string parameter does not take into account sql_mode value.
Fix:
========================
So when sql_mode is set to "NO_BACKSLASH_ESCAPES", escaping characters as
(n, r, ', ", \, 0...) should be avoided. To do so, added a check to not to
escape such characters while writing NAME_CONST for string variables in bin
log.
And when sql_mode is set to NO_BACKSLASH_ESCAPES, quote character "'" is
represented as ''.
http://dev.mysql.com/doc/refman/5.6/en/string-literals.html (There are several
ways to include quote characters within a string: )
Problem - The default port number shown in SHOW SLAVE HOSTS is always 3306
though the slave is actually listening on a different port number.
This is a problem as the user can not be sure whether this port
value can be trusted and so client trying to read replication
topology can get confused.
Fix - 3306 ceases to be the default value of report-port. Moreover report-port
does not have a static default any longer.
Instead we initialize report-port to 0 as the new default value and change
it based on two checks :
1) If report_port is not set, the slave reports the port number its listening
on. (i.e. if report-port is not set we get the actual value of the slave's
port number).
2) If report-port is set, we show the value report-port is set to, as the slave's
port number.
There are two threads. In one thread, dml operation is going on
involving cascaded update operation. In another thread, alter
table add foreign key constraint is happening. Under these
circumstances, it is possible for the dml thread to access a
dict_foreign_t object that has been freed by the ddl thread.
The debug sync test case provides the sequence of operations.
Without fix, the test case will crash the server (because of
newly added assert). With fix, the alter table stmt will return
an error message.
rb:947
approved by Jimmy Yang
