binlog coordinates corresponding to the dump".
The good news is that now mysqldump can be used to get an online backup of InnoDB *which works for
point-in-time recovery and replication slave creation*. Formerly, mysqldump --master-data --single-transaction
used to call in fact mysqldump --master-data, so the dump was not an online dump (took big lock all time of dump).
The only lock which is now taken in this patch is at the beginning of the dump: mysqldump does:
FLUSH TABLES WITH READ LOCK; START TRANSACTION WITH CONSISTENT SNAPSHOT; SHOW MASTER STATUS; UNLOCK TABLES;
so the lock time is in fact the time FLUSH TABLES WITH READ LOCK takes to return (can be 0 or very long, if
a table is undergoing a huge update).
I have done some more minor changes listed in the paragraph of mysqldump.c.
WL#2237 "WITH CONSISTENT SNAPSHOT clause for START TRANSACTION":
it's a START TRANSACTION which additionally starts a consistent read on all
capable storage engine (i.e. InnoDB). So, can serve as a replacement for
BEGIN; SELECT * FROM some_innodb_table LIMIT 1; which starts a consistent read too.
DROP DATABASE failed because of file ext not in TYPELIB of known extensions.
General solution - construct a TYPELIB at runtime instead of a static list.
When we are writing a transaction to the binlog, we log BEGIN/COMMIT with zero error code.
Example: all statements of trans succeeded, connection lost and so implicit rollback:
we don't want ER_NET* errors to be logged in the BEGIN/ROLLBACK events, while statement
events have 0. If there was really a serious error code, it's already in the statement events.
the result takes its charset/collation
attributes from the character string,
e.g. SELECT func(NULL, _latin2'string')
now returns a latin2 result. This is
done by introducing a new derivation
(aka coercibility) level DERIVATION_IGNORABLE,
which is used with Item_null.
2. 'Pure' NULL is now BINARY(0), not CHAR(0).
I.e. NULL is now more typeless.
not know there's rollback (if it's because of a dupl row), better warn
that it's happening. It can also be of use for a DBA killing a
connection and wondering what this connection is still doing now. Example:
| 5 | root | localhost | test | Killed | 10 | Rolling back | insert into i select * from j |
Bug #6479 ALTER TABLE ... changing charset fails for TEXT columns
Fix: use do_conv_blob rather than do_copy_blob
if the column's character sets are different.
1) fix so that missing blob tables don't prevent table from being
dropped
2) decrease size of blob part if record length exceeds max length
3) add test case for table wo/ corresponding blob table
4) init scan counters when sending scan_tabreq
Now thd->mem_root is a pointer to thd->main_mem_root and THR_MALLOC is a pointer to thd->mem_root.
This gives us the following benefits:
- Allow us to easily detect if arena has already been swapped before (this fixes a bug in setup_conds() where arena was swaped twice in some cases)
- Faster swaps of arenas (as we don't have to copy the whole MEM_ROOT)
- We don't anymore have to call my_pthread_setspecific_ptr(THR_MALLOC,...) to change where memory is alloced. Now it's enough to set thd->mem_root
Added cases for bugs #6307 and #6460.
sql_select.cc:
Fixed the problem of bug reports #6307 and #6460.
The reported wrong result sets were due to the fact that
the added call of the fix_fields method for the built
AND condition that joined WHERE and ON conditions
broke ON expression, as it removed extra AND levels
in the built condition.
It looks like that no attributes of the built condition
are needed, so we don't have to call fix_fields here.
of client equals to character set of connection, possibly required
conversion to character set of column is not performed
(prepared statements, data is supplied using placeholders).
character set with NULL, @a should be latin2
after this query sequence:
SET @a=_latin2'string';
SET @a=NULL;
I.e. the second query should not change the charset
to the current default value, but should keep the
original value assigned during the first query.
In order to do it, we don't copy charset
from the argument if the argument is NULL
and the variable has previously been initialized.
Added a case for bug #6365.
item_cmpfunc.cc:
Fixed bug #6365 : Server crashed when list of values
in IN predicate contains NULL while the tested field is
of the character type and not of the default set;
e.g. when f in 'f IN (NULL,'aa') belongs to binary
character set, while the default character set is latin1.
