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).
Note: Backporting the patch from mysql-5.6.
Problem:
A CREATE TABLE with an invalid table name is detected
at SQL layer. So the table name is reset to an empty
string. But the storage engine is called with this
empty table name. The table name is specified as
"database/table". So, in the given scenario we get
only "database/".
Solution:
Within InnoDB, detect this error and report it to
higher layer.
rb#9274 approved by jimmy.
was fixed in HA_CONNECT::CondFilter moving res= pval->val_str(&tmp)
but this was wrong. Now res is only used for strings.
modified: storage/connect/ha_connect.cc
recv_find_max_checkpoint(): Amend the error message to give advice
about downgrading. The 5.7.9 redo log format was intentionally changed
so that older MySQL versions will not find a valid redo log checkpoint.
This can happen in odbconn.cpp when SQLFetch returns SQL_NO_TOTAL (-4) as length.
modified: storage/connect/odbconn.cpp
modified: storage/connect/value.cpp
of more than 45G with a key_cache_block_size of 1024 or less.
The problem was that some of the arguments to my_multi_malloc() got to be
more than 4G.
Fix:
- Inntroduced my_multi_malloc_large() that can handle big regions.
- Changed MyISAM and Aria key caches to use my_multi_malloc_large().
I didn't change the default my_multi_malloc() as this would be a too big
patch and we don't allocate 4G blocks anywhere else.
PROBLEM
Whenever we insert in unique secondary index we take shared
locks on all possible duplicate record present in the table.
But while during a replace on the unique secondary index ,
we take exclusive and locks on the all duplicate record.
When the records are deleted, they are first delete marked
and later purged by the purge thread. While purging the
record we call the lock_update_delete() which in turn calls
lock_rec_inherit_to_gap() to inherit locks of the deleted
records. In repeatable read mode we inherit all the locks
from the record to the next record but in the read commited
mode we skip inherting them as gap type locks. We make a
exception here if the lock on the records is in shared mode
,we assume that it is set during insert for unique secondary
index and needs to be inherited to stop constraint violation.
We didnt handle the case when exclusive locks are set during
replace, we skip inheriting locks of these records and hence
causing constraint violation.
FIX
While inheriting the locks,check whether the transaction is
allowed to do TRX_DUP_REPLACE/TRX_DUP_IGNORE, if true
inherit the locks.
[ Revewied by Jimmy #rb9709]
The root cause is that x86 has a stronger memory model than the ARM
processors. And the GCC builtins didn't issue the correct fences when
setting/unsetting the lock word. In particular during the mutex release.
The solution is rewriting atomic TAS operations: replace '__sync_' by
'__atomic_' if possible.
Reviewed-by: Sunny Bains <sunny.bains@oracle.com>
Reviewed-by: Bin Su <bin.x.su@oracle.com>
Reviewed-by: Debarun Banerjee <debarun.banerjee@oracle.com>
Reviewed-by: Krunal Bauskar <krunal.bauskar@oracle.com>
RB: 9782
RB: 9665
RB: 9783
