After table->file->add_index() in mysql_alter_table() the table in the engine
has the intermediate temporary structure, it's neither the original nor the
final table structure (it'll be final after successful table->file->drop_index()
call). So, when add_index() fails with a unique key violation, we cannot simply
get the failed key number and easily map it to the key name and key structure via
table->key_info[key_no].
For now we'll create this "intermediate temporary structure", emulating InnoDB
internal rules.
This bug and the fix will go away in 10.0 that uses completely different online
alter table code.
mysql-test/t/alter_table_trans.test:
mdev:5406
STATUS OF ROLLBACKED TRANSACTION" and bug #17054007 - "TRANSACTION
IS NOT FULLY ROLLED BACK IN CASE OF INNODB DEADLOCK".
The problem in the first bug report was that although deadlock involving
metadata locks was reported using the same error code and message as InnoDB
deadlock it didn't rollback transaction like the latter. This caused
confusion to users as in some cases after ER_LOCK_DEADLOCK transaction
could have been restarted immediately and in some cases rollback was
required.
The problem in the second bug report was that although InnoDB deadlock
caused transaction rollback in all storage engines it didn't cause release
of metadata locks. So concurrent DDL on the tables used in transaction was
blocked until implicit or explicit COMMIT or ROLLBACK was issued in the
connection which got InnoDB deadlock.
The former issue has stemmed from the fact that when support for detection
and reporting metadata locks deadlocks was added we erroneously assumed
that InnoDB doesn't rollback transaction on deadlock but only last statement
(while this is what happens on InnoDB lock timeout actually) and so didn't
implement rollback of transactions on MDL deadlocks.
The latter issue was caused by the fact that rollback of transaction due
to deadlock is carried out by setting THD::transaction_rollback_request
flag at the point where deadlock is detected and performing rollback
inside of trans_rollback_stmt() call when this flag is set. And
trans_rollback_stmt() is not aware of MDL locks, so no MDL locks are
released.
This patch solves these two problems in the following way:
- In case when MDL deadlock is detect transaction rollback is requested
by setting THD::transaction_rollback_request flag.
- Code performing rollback of transaction if THD::transaction_rollback_request
is moved out from trans_rollback_stmt(). Now we handle rollback request
on the same level as we call trans_rollback_stmt() and release statement/
transaction MDL locks.
IN TIME RECOVERY FAILURE ON SLAVES
Problem:
DROP TEMP TABLE IF EXISTS commands can cause point
in time recovery (re-applying binlog) failures.
Analyses:
In RBR, 'DROP TEMPORARY TABLE' commands are
always binlogged by adding 'IF EXISTS' clauses.
Also, the slave SQL thread will not check replicate.* filter
rules for "DROP TEMPORARY TABLE IF EXISTS" queries.
If log-slave-updates is enabled on slave, these queries
will be binlogged in the format of "USE `db`;
DROP TEMPORARY TABLE IF EXISTS `t1`;" irrespective
of filtering rules and irrespective of the `db` existence.
When users try to recover slave from it's own binlog,
use `db` command might fail if `db` is not present on slave.
Fix:
At the time of writing the 'DROP TEMPORARY TABLE
IF EXISTS' query into the binlog, 'use `db`' will not be
present and the table name in the query will be a fully
qualified table name.
Eg:
'USE `db`; DROP TEMPORARY TABLE IF EXISTS `t1`;'
will be logged as
'DROP TEMPORARY TABLE IF EXISTS `db`.`t1`;'.
1. DROP DATABASE should use ha_discover_table_names(), not look at .frm files.
2. filename_to_tablename() also encodes temp file names #sql- -> #mysql50##sql
3. no special treatment for #sql- files, no TABLE_LIST::internal_tmp_table
4. discover also table file names, that start from #
CAN LEAD TO MISSING TABLES
Overview
--------
If the FOREIGN_KEY_CHECKS system variable is set to 0, it is
possible to break a foreign key constraint by changing the type
or character set of the foreign key column, or by dropping the
foreign key index (without carrying out corresponding changes on
another table in the relationship).
If we subsequently set FOREIGN_KEY_CHECKS to 1 and execute ALTER
TABLE involving the COPY algorithm on such a table, the following
happens:
1) If ALTER TABLE does not contain a RENAME clause, the attempt
to install the new version of the table instead of the old one
will fail due to the fact that the inconsistency will be
detected. An attempt to revert the partially executed alter
table operation by restoring the old table definition will
fail as well due to FOREIGN_KEY_CHECKS == 1. As a result, the
table being altered will be lost.
2) If ALTER TABLE contains the RENAME clause, the inconsistency
will not be detected (most probably due to other bugs). But if
an attempt to install the new version of the table fails (for
example, due to a failure when updating triggers associated
with the table), reverting the partially executed alter table
by restoring the old table definition will fail too. So the
table being altered might be lost as well.
Suggested fix
-------------
The suggested fix is to temporarily unset the option bit
representing FOREIGN_KEY_CHECKS when the old table definition is
restored while reverting the partially executed operation.
Syntax modified to allow statements:
ALTER TABLE ADD/DROP COLUMN
ALTER TABLE ADD/DROP INDEX
ALTER TABLE ADD/DROP FOREIGN KEY
ALTER TABLE ADD/DROP PARTITION
ALTER TABLE CHANGE COLUMN
ALTER TABLE MODIFY COLUMN
DROP INDEX
to have IF (NOT) EXISTS options.
Appropriate implementations added to mysql_alter_table().
per-file comments:
mysql-test/r/alter_table.result
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
test result updated.
mysql-test/r/fulltext.result
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
mysql-test/r/partition.result
test result updated.
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
mysql-test/t/alter_table.test
tests added.
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
mysql-test/t/fulltext.test
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
tests added.
mysql-test/t/partition.test
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
tests added.
sql/field.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
create_if_not_exists field added.
sql/field.h
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
create_if_not_exists field added.
sql/partition_info.h
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
has_unique_name made public.
sql/sp_head.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
sql/sql_class.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
create_if_not_exists inited.
sql/sql_class.h
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
create_if_not_exists inited.
sql/sql_lex.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
check_exists inited.
sql/sql_lex.h
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
check_exists inited.
sql/sql_parse.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
check_exists inited.
sql/sql_table.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
handle_if_exists_options() added.
it's called in mysql_alter_table().
sql/sql_trigger.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
check_exists instead of drop_if_exists.
sql/sql_view.cc
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
check_exists instead of drop_if_exists.
sql/sql_yacc.yy
MDEV-318 IF (NOT) EXIST clauses for ALTER TABLE (MWL #252).
sintax modified.
"
revision-id: sanja@askmonty.org-20110511110948-4kdevwzomvk56y1w
committer: sanja@askmonty.org
branch nick: work-maria-5.1-CREATE-merge
timestamp: Wed 2011-05-11 14:09:48 +0300
Bugfix: New table creation/renaming block added if old encoded table present
"
the old behavior was less inconsistent than the new one.
In the new one the error message was sometimes different (under LOCK TABLES e.g.),
and there were race conditions (if this CREATE happened when a concurrent ALTER
has renamed the old table away but haven't put the new table in place)
The old one was like "(when using old table names) for DML #mysql50# prefix
is optional, for DDL it's required".
* print "table doesn't exist in engine" when a table doesn't exist in the engine,
instead of "file not found" (if no file was involved)
* print a complete filename that cannot be found ('t1.MYI', not 't1')
* it's not an error for a DROP if a table doesn't exist in the engine (or some table
files cannot be found) - if the DROP succeeded regardless
SHOW ENGINE INNOD
Problem:
The purpose of explain_filename() is to provide useful additional
information regarding the partitions given the filename. This function
was returning an error when it was not able to parse the given filename.
For example, within InnoDB, temporary files are created with #sql-
prefix. But this function was not able to parse it correctly.
Solution:
It is not an error, if explain_filename() could not parse the given
filename. If there is no partition information to explain, then silently
return from the function.
rb#1940 approved by mattiasj
sql/sql_table.cc:
Don't call allow_access_to_protected_table() if we haven't protected table against usage.
Table is mainly protected against usage when one disables keys with alter table.
sql/sql_table.cc:
Remove version protection from share when repair has been done.
Without this one can't run SHOW commands on the table if it was locked until it's unlocked.
sql/table.h:
Allow one to remove version protection with allow_access_to_protected_table()
