Add deprecation warning when variable optimizer_search_depth is given
the value 63.
mysql-test/r/greedy_optimizer.result
Updated with warning text.
mysql-test/r/mysqld--help-notwin.result
Updated with warning from mysqld --help --verbose.
mysql-test/r/mysqld--help-win.result
Updated with warning from mysqld --help --verbose.
sql/sys_vars.cc
Added an update check function to the constructor invocation for
the optimizer_search_depth variable. The function emits a
warning message for the value 63.
Since 5.5 FLUSH TABLES requires unlocked tables so the old LOCK TABLES/FLUSH TABLES
model fails. Use atomic FLUSH TABLES WITH READ LOCK instead.
per-file comments:
scripts/mysqlhotcopy.sh
Bug#42465 mysqlhotcopy fails with "Table '<y>' was locked with a READ lock" error message.
Use FLUSH TABLES WITH READ LOCK instead of LOCK TABLES / FLUSH TABLES pair.
Keep the old scheme for older servers.
There was auto-reconnecting by slave earlier than a prescribed by slave_net_timeout value.
The issue happened on 64bit solaris that spotted rather incorrect casting of
the ulong slave_net_timeout into the uint of mysql.options.read_timeout.
Notice, that there is no reason for slave_net_timeout to be of type of ulong.
Since it's primarily passed as arg to mysql_options the type can be made
as uint to avoid all conversion hassles.
That's what the fixes are made.
A "side" effect of the patch is a new value for the max of slave_net_timeout
to be the max of the unsigned int type (therefore to vary across platforms).
Note, a regression test can't be made to run reliably without making it to last over some
20 secs. That's why it is placed in suite/large_tests.
on Windows".
On platforms where read-write lock implementation does not
prefer readers by default (Windows, Solaris) server might
have deadlocked while detecting MDL deadlock.
MDL deadlock detector relies on the fact that read-write
locks which are used in its implementation prefer readers
(see new comment for MDL_lock::m_rwlock for details).
So far MDL code assumed that default implementation of
read/write locks for the system has this property.
Indeed, this turned out ot be wrong, for example, for
Windows or Solaris. Thus MDL deadlock detector might have
deadlocked on these systems.
This fix simply adds portable implementation of read/write
lock which prefer readers and changes MDL code to use this
new type of synchronization primitive.
No test case is added as existing rqg_mdl_stability test can
serve as one.
Extend and implement the grammar that allows to FLUSH WITH READ LOCK
a list of tables, rather than all of them.
Incompatible grammar change:
Previously one could perform FLUSH TABLES, HOSTS, PRIVILEGES in a single
statement.
After this change, FLUSH TABLES must always be alone on the list.
Judging by the test suite, however, the old extended syntax
was never or very rarely used.
The new statement requires RELOAD ACL global privilege and
LOCK_TABLES_ACL | SELECT_ACL on individual tables.
In other words, it's an atomic combination of LOCK TALBES <list> READ
and FLUSH TABLES <list>, and requires respective privileges.
For additional information about the semantics, please
see WL#5000 and the comment for flush_tables_with_read_lock()
function in sql_parse.cc
Before this fix, the performance schema file instrumentation would treat:
- a relative path to a file
- an absolute path to the same file
as two different files.
This would lead to:
- separate aggregation counters
- file leaks when a file is removed.
With this fix, a relative and absolute path are resolved to the same file instrument.
The problem was that ALTER TABLE on a merge table which was locked
using LOCK TABLE ... WRITE, by mistake gave
ER_TABLE_NOT_LOCKED_FOR_WRITE.
During opening of the table to be ALTERed, open_table() tried to
get an upgradable metadata lock. In LOCK TABLEs mode, this lock
must already exist (i.e. taken by LOCK TABLE) as new locks of this
type cannot be acquired for fear of deadlock. So in LOCK TABLEs
mode, open_table() tried to find an existing upgradable lock for
the table to be altered.
The problem was that open_table() also tried to find upgradable
metadata locks for children of merge tables even if no such
locks are needed to execute ALTER TABLE on merge tables.
This patch fixes the problem by making sure that open tables code
only searches for upgradable metadata locks for the merge table
and not for the merge children tables.
The patch also fixes a related bug where an upgradable metadata
lock was aquired outside of LOCK TABLEs mode even if the table in
question was temporary. This bug meant that LOCK TABLES or DDL on
temporary tables by mistake could be blocked/aborted by locks held
on base tables with the same table name by other connections.
Test cases added to merge.test and lock_multi.test.
The problem is that cond->fix_fields(thd, 0) breaks
condition(cuts off 'having'). The reason of that is
that NULL valued Item pointer is present in the
middle of Item list and it breaks the Item processing
loop.
performance degradation.
Filesort + join cache combination is preferred to full index scan because it
is usually faster. But it's not the case when the index is clustered one.
Now test_if_skip_sort_order function prefers filesort only if index isn't
clustered.
