LOSS
ANALYSIS:
=========
When converting from a BLOB/TEXT type to a smaller
BLOB/TEXT type, no warning/error is reported to the user
informing about the truncation/data loss.
FIX:
====
We are now reporting a warning in non-strict mode and an
appropriate error in strict mode.
backport ce6c0e584e
MDEV-8960: Can't refer the same column twice in one ALTER TABLE
Problem was that if column was created in alter table when
it was refered again it was not tried to find from list
of current columns.
mysql_prepare_alter_table:
There is two cases
(1) If alter table adds a new column and then later alter
changes the field definition, there was no check from
list of new columns, instead an incorrect error was given.
(2) If alter table adds a new column and then later alter
changes the default, there was no check from list of
new columns, instead an incorrect error was given.
Problem was that if column was created in alter table when
it was refered again it was not tried to find from list
of current columns.
mysql_prepare_alter_table:
There is two cases
(1) If alter table adds a new column and then later alter
changes the field definition, there was no check from
list of new columns, instead an incorrect error was given.
(2) If alter table adds a new column and then later alter
changes the default, there was no check from list of
new columns, instead an incorrect error was given.
be consistent and don't include the table name into the error message,
no other CREATE TABLE error does it.
(the crash happened, because thd->lex->query_tables was NULL)
FILE
PROBLEM
In 5.5 when doing doing a rename of a column ,we ignore the case between
old and new column names while comparing them,so if the change is just
the case then we don't even mark the field FIELD_IS_RENAMED ,we just update
the frm file ,but don't recreate the table as is the norm when alter is
used.This leads to inconsistency in the innodb data dictionary which causes
index creation to fail.
FIX
According to the documentation any innodb column rename should trigger
rebuild of the table. Therefore for innodb tables we will do a strcmp()
between the column names and if there is case change in column name
we will trigger a rebuild.
In original code, sometimes one got an automatic DEFAULT value in some cases, in other cases not.
For example:
create table t1 (a int primary key) - No default
create table t2 (a int, primary key(a)) - DEFAULT 0
create table t1 SELECT .... - Default for all fields, even if they where defined as NOT NULL
ALTER TABLE ... MODIFY could sometimes add an unexpected DEFAULT value.
The patch is quite big because we had some many test cases that used
CREATE ... SELECT or CREATE ... (...PRIMARY KEY(xxx)) which doesn't have an automatic DEFAULT anymore.
Other things:
- Removed warnings from InnoDB when waiting from semaphore (got this when testing things with --big)
Patches for server and the Innodb engine.
Server is fixed so it does nothing if no indexes left to alter.
Innodb parser is fixed so it looks for the IF [NOT] EXISTS option in a string.
Another change is that it uses the index name for the internal dictionary.
Prior to that it only used the CONSTRAINT name for it.
* update results
* don't force HA_CREATE_DELAY_KEY_WRITE on all temp tables,
(bad for CREATE ... LIKE) instead imply it in myisam/aria
* restore HA_ERR_TABLE_DEF_CHANGED in archive
* increase the default number of rwlock classes in P_S to fit all our rwlocks
includes:
* remove some remnants of "Bug#14521864: MYSQL 5.1 TO 5.5 BUGS PARTITIONING"
* introduce LOCK_share, now LOCK_ha_data is strictly for engines
* rea_create_table() always creates .par file (even in "frm-only" mode)
* fix a 5.6 bug, temp file leak on dummy ALTER TABLE
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.
The patch lifts the limitation of the current implementation
of ALTER TABLE that does not allow to build unique/primary
indexes by sort for MyISAM and Aria engines.
TABLES IN INCORRECT ENGINE
PROBLEM:
CREATE/ALTER TABLE currently can move system tables like
mysql.db, user, host etc, to engines other than MyISAM. This is not
completely supported as of now, by mysqld. When some of system tables
like plugin, servers, event, func, *_priv, time_zone* are moved
to innodb, mysqld restart crashes. Currently system tables
can be moved to BLACKHOLE also!!!.
ANALYSIS:
The problem is that there is no check before creating or moving
a system table to some particular engine.
System tables are suppose to be residing in MyISAM. We can think
of restricting system tables to exist only in MyISAM. But, there could
be future needs of these system tables to be part of other engines
by design. For eg, NDB cluster expects some tables to be on innodb
or ndb engine. This calls for a solution, by which system
tables can be supported by any desired engine, with minimal effort.
FIX:
The solution provides a handlerton interface using which,
mysqld server can query particular storage engine handlerton for
system tables that it supports. This way each storage engine
layer can define their own system database and system tables.
The check_engine() function uses the new handlerton function
ha_check_if_supported_system_table() to check if db.tablename
provided in the DDL is supported by the SE.
Note: This fix has modified a test in help.test, which was moving
mysql.help_* to innodb. The primary intention of the test was not
to move them between engines.
