Analysis: Current implementation will write and read at least one block
(sort_buffer_size bytes) from disk / index even if that block does not
contain any records.
Fix: Avoid writing / reading empty blocks to temporary files (disk).
There is several different ways to incorrectly define
foreign key constraint. In many cases earlier MariaDB
versions the error messages produced by these cases
are not very clear and helpful. This patch improves
the warning messages produced by foreign key parsing.
Analysis: At check_trx_exists function InnoDB allocates
a new trx if no trx is found from thd but this newly
allocated trx is not registered to thd. This is unsafe,
because nothing prevents InnoDB plugin from being uninstalled
while there's active transaction. This can cause crashes, hang
and any other odd behavior. It may also corrupt stack, as
functions pointers are not available after dlclose.
Fix: The fix is to use thd_set_ha_data() when
manipulating per-connection handler data. It does appropriate
plugin locking.
Analysis; Problem is that InnoDB does not have support for generating
CURRENT_TIMESTAMP or constant default.
Fix: Add additional check if column has changed from NULL -> NOT NULL
and column default has changed. If this is is first column definition
whose SQL type is TIMESTAMP and it is defined as NOT NULL and
it has either constant default or function default we must use
"Copy" method for alter table.
Add progress info on InnoDB/XtraDB row0merge phase. Note that we
do not know exact number of rounds merge sort needs at start thus
also progress report might not be accurate.
Analysis: Problem is that SQL-layer calls handler API after storage
engine has already returned error state. InnoDB does internal
rollback when it notices transaction error (e.g. lock wait timeout,
deadlock, etc.) and after this transaction is not naturally in
correct state to continue.
Fix: Do not continue fetch operations if transaction is not started.
This is an addendum to the fix for MDEV-7026. The ARM memory model is
similar to that of PowerPC and thus needs the same semantics with
respect to memory barriers. That is, os_atomic_test_and_set_*_release()
must be a store with a release barrier followed by a full
barrier. Unlike x86 using __sync_lock_test_and_set() which is
implemented as “exclusive load with acquire barriers + exclusive store”
is insufficient in contexts where os_atomic_test_and_set_*_release()
macros are used.
Problem was that std::vector was allocated using calloc instead of
new, this caused vector constructor not being called and vector
metadata not initialized.
if XA PREPARE transactions hold explicit locks.
innobase_shutdown_for_mysql(): Call trx_sys_close() before lock_sys_close()
(and dict_close()) so that trx_free_prepared() will see all locks intact.
RB: 8561
Reviewed-by: Vasil Dimov <vasil.dimov@oracle.com>
PROBLEM
Create time is calculated as last status change time of .frm file.
The first problem was that innodb was passing file name as
"table_name#po#p0.frm" to the stat() call which calculates the create time.
Since there is no frm file with this name create_time will be stored as NULL.
The second problem is ha_partition::info() updates stats for create time
when HA_STATUS_CONST flag was set ,where as innodb calculates this statistic
when HA_STATUS_TIME is set,which causes create_time to be set as NULL.
Fix
Pass proper .frm name to stat() call and calculate create time when
HA_STATUS_CONST flag is set.
Analysis: MySQL table definition contains also virtual columns. Similarly,
index fielnr references MySQL table fields. However, InnoDB table definition
does not contain virtual columns. Therefore, when matching MySQL key fieldnr
we need to use actual column name to find out referenced InnoDB dictionary
column name.
Fix: Add new function to match MySQL index key columns to InnoDB dictionary.
TO USE A SECOND WATCH PAGE PER INSTANCE
Description:
BUF_POOL_WATCH_SIZE is also initialized to number of purge threads.
so BUF_POOL_WATCH_SIZE will never be lesser than number of purge threads.
From the code, there is no scope for purge thread to skip buf_pool_watch_unset.
So there can be at most one buffer pool watch active per purge thread.
In other words, there is no chance for purge thread instance to hold a watch
when setting another watch.
Solution:
Adding code comments to clarify the issue.
Reviewed-by: Marko Mäkelä <marko.makela@oracle.com>
Approved via Bug page.
