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()
The issue was that there was that SHOW commands could open the table in the store engine, even in cases
where it should not be allowed to do that (ie, the storage engines meta data for that table was under big changes).
The cases where this should not be allowed are:
- ALTER TABLE DISABLE KEYS
- ALTER TABLE ENABLE KEYS
- REPAIR TABLE
- OPTIMIZE TABLE
- DROP TABLE
This patch adds a new mode, protected_against_usage(). If this is used then the SHOW command will wait until the table
is accessable. This is implemented by re-using the already exising 'version' flag for TABLE_SHARE.
It also added functions to be used to change TABLE_SHARE->version instead of changing it directly.
mysql-test/r/myisam-metadata.result:
Added test case
mysql-test/t/myisam-metadata.test:
Added test case
sql/mysqld.cc:
Start from refresh_version 2 as 0 and 1 are reserved.
sql/sql_admin.cc:
Added MYSQL_OPEN_FOR_REPAIR
Updated call to wait_while_table_is_used()
sql/sql_base.cc:
Updated call to wait_while_table_is_used()
- Allow one to specify how the table should be removed (for all commands except show or for all commands).
- Don't allow one to reopen the table if one has called share->protect_against_usage()
sql/sql_base.h:
Added TDC_RT_REMOVE_NOT_OWN_AND_MARK_NOT_USABLE, which is used to mark that no one can reopen this table, except with MYSQL_OPEN_FOR_REPAIR .
- Added MYSQL_OPEN_FOR_REPAIR
- Updated prototype for wait_while_table_is_used()
sql/sql_table.cc:
Updated call to wait_while_table_is_used()
Use MYSQL_OPEN_FOR_REPAIR for open tables that where repaired.
sql/sql_truncate.cc:
Updated call to wait_while_table_is_used()
sql/table.cc:
Use set_refresh_version()
sql/table.h:
Added functions to be used to change TABLE_SHARE->version instead of changing it directly
mysys/errors.c:
revert upstream's fix. use a much simpler one
mysys/my_write.c:
revert upstream's fix. use a simpler one
sql/item_xmlfunc.cc:
useless, but ok
sql/mysqld.cc:
simplify upstream's fix
storage/heap/hp_delete.c:
remove upstream's fix.
we'll use a much less expensive approach.
