Item_func_user doesn't calculate anything in it's val_str() method,
just returns saved str_value.
Though Item::save_in_field method can destroy str_value, relying on
val_str() return. As a result we get the garbage stored in field.
We cannot use Item::save_in_field implementation for Item_func_user,
reimplement it in simpler way.
- make ha_berkeley::cmp_ref() take into account that auto-generated PKs
are stored in LSB-first order.
- Remove the temporary code that made the bugfix work for innodb only
the master but on the slave
MySQL can decide to "downgrade" a INSERT DELAYED statement
to normal insert in certain situations.
One such situation is when the slave is replaying a
replication feed.
However INSERT DELAYED is logged even if there're no updates
whereas the NORMAL INSERT is not logged in such cases.
Fixed by always logging a "downgraded" INSERT DELAYED: even
if there were no updates.
"Federated Denial of Service"
Federated storage engine used to attempt to open connections within
the ::create() and ::open() methods which are invoked while LOCK_open
mutex is being held by mysqld. As a result, no other client sessions
can open tables while Federated is attempting to open a connection.
Long DNS lookup times would stall mysqld's operation and a rogue
connection string which connects to a remote server which simply
stalls during handshake can stall mysqld for a much longer period of
time.
This patch moves the opening of the connection much later, when the
federated actually issues queries, by which time the LOCK_open mutex is
no longer being held.
When the SQL_BIG_RESULT flag is specified SELECT should store items from the
select list in the filesort data and use them when sending to a client.
The get_addon_fields function is responsible for creating necessary structures
for that. But this function was allowed to do so only for SELECT and
INSERT .. SELECT queries. This makes the SQL_BIG_RESULT useless for
the CREATE .. SELECT queries.
Now the get_addon_fields allows storing select list items in the filesort
data for the CREATE .. SELECT queries.
"getGeneratedKeys() does not work with FEDERATED table"
mysql_insert() expected the storage engine to update the row data
during the write_row() operation with the value of the new auto-
increment field. The field must be updated when only one row has
been inserted as mysql_insert() would ignore the thd->last_insert.
This patch implements HA_STATUS_AUTO support in ha_federated::info()
and ensures that ha_federated::write_row() does update the row's
auto-increment value.
The test case was written in C as the protocol's 'id' value is
accessible through libmysqlclient and not via SQL statements.
mysql-test-run.pl was extended to enable running the test binary.
If a primary key is defined over column c of enum type then
the EXPLAIN command for a look-up query of the form
SELECT * FROM t WHERE c=0
said that the query was with an impossible where condition though the
query correctly returned non-empty result set when the table indeed
contained rows with error empty strings for column c.
This kind of misbehavior was due to a bug in the function
Field_enum::store(longlong,bool) that erroneously returned 1 if
the the value to be stored was equal to 0.
Note that the method
Field_enum::store(const char *from,uint length,CHARSET_INFO *cs)
correctly returned 0 if a value of the error empty string
was stored.
This bug manifested itself for join queries with GROUP BY and HAVING clauses
whose SELECT lists contained DISTINCT. It occurred when the optimizer could
deduce that the result set would have not more than one row.
The bug could lead to wrong result sets for queries of this type because
HAVING conditions were erroneously ignored in some cases in the function
remove_duplicates.
ORDER BY primary_key on InnoDB table
Queries that use an InnoDB secondary index to retrieve
data don't need to sort in case of ORDER BY primary key
if the secondary index is compared to constant(s).
They can also skip sorting if ORDER BY contains both the
the secondary key parts and the primary key parts (in
that order).
This is because InnoDB returns the rows in order of the
primary key for rows with the same values of the secondary
key columns.
Fixed by preventing temp table sort for the qualifying
queries.
by long running transaction
On Windows opened files can't be deleted. There was a special
upgraded lock mode (TL_WRITE instead of TL_WRITE_ALLOW_READ)
in ALTER TABLE to make sure nobody has the table opened
when deleting the old table in ALTER TABLE. This special mode
was causing ALTER TABLE to hang waiting on a lock inside InnoDB.
This special lock is no longer necessary as the server is
closing the tables it needs to delete in ALTER TABLE.
Fixed by removing the special lock.
Note that this also reverses the fix for bug 17264 that deals with
another consequence of this special lock mode being used.
The Item_date_typecast::val_int function doesn't reset null_value flag.
This makes all values that follows the first null value to be treated as nulls
and led to a wrong result.
Now the Item_date_typecast::val_int function correctly sets the null_value flag
for both null and non-null values.
a temporary table.
The result string of the Item_func_group_concat wasn't initialized in the
copying constructor of the Item_func_group_concat class. This led to a
wrong charset of GROUP_CONCAT result when the select employs a temporary
table.
The copying constructor of the Item_func_group_concat class now correctly
initializes the charset of the result string.
No test case, since the bug requires a stress case with 30 INSERT DELAYED
threads and 1 killer thread to repeat. The patch is verified
manually.
Review fixes.
The server that is running DELAYED inserts would deadlock itself
or crash under high load if some of the delayed threads were KILLed
in the meanwhile.
The fix is to change internal lock acquisition order of delayed inserts
subsystem and to ensure that
Delayed_insert::table_list::db does not point to volatile memory in some
cases.
For details, please see a comment for sql_insert.cc.
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).
to CHECK TABLE
CHECK/REPAIR TABLE reports "File not found" error when issued
against temporary table.
Fixed by disabling a brunch of code (in case it gets temporary table)
that is responsible for updating frm version as it is not needed
for temporary tables.
Removed duplicate call to handler::external_lock() when
ALTER TABLE that doesn't need to copy a table (quick
ALTER TABLE) was executed.
Also quick ALTER TABLE doesn't hold LOCK_open anymore when
it enables/disables indexes.
