with open HANDLER
Fixes a problem with schema.test visible using embedded server.
The HANDLER was not closed which caused the test to hang.
The problem was not visible if the test was run on a normal server
as the the handler there was implicitly closed by DATABASE DDL
statements doing Events::drop_schema_events().
DATABASE with open HANDLER"
Remove LOCK_create_db, database name locks, and use metadata locks instead.
This exposes CREATE/DROP/ALTER DATABASE statements to the graph-based
deadlock detector in MDL, and paves the way for a safe, deadlock-free
implementation of RENAME DATABASE.
Database DDL statements will now take exclusive metadata locks on
the database name, while table/view/routine DDL statements take
intention exclusive locks on the database name. This prevents race
conditions between database DDL and table/view/routine DDL.
(e.g. DROP DATABASE with concurrent CREATE/ALTER/DROP TABLE)
By adding database name locks, this patch implements
WL#4450 "DDL locking: CREATE/DROP DATABASE must use database locks" and
WL#4985 "DDL locking: namespace/hierarchical locks".
The patch also changes code to use init_one_table() where appropriate.
The new lock_table_names() function requires TABLE_LIST::db_length to
be set correctly, and this is taken care of by init_one_table().
This patch also adds a simple template to help work with
the mysys HASH data structure.
Most of the patch was written by Konstantin Osipov.
This was a deadlock between LOCK TABLES/CREATE DATABASE in one connection
and DROP DATABASE in another. It only happened if the table locked by
LOCK TABLES was in the database to be dropped. The deadlock is similar
to the one in Bug#48940, but with LOCK TABLES instead of an active
transaction.
The order of events needed to trigger the deadlock was:
1) Connection 1 locks table db1.t1 using LOCK TABLES. It will now
have a metadata lock on the table name.
2) Connection 2 issues DROP DATABASE db1. This will wait inside
the MDL subsystem for the lock on db1.t1 to go away. While waiting, it
will hold the LOCK_mysql_create_db mutex.
3) Connection 1 issues CREATE DATABASE (database name irrelevant).
This will hang trying to lock the same mutex. Since this is the connection
holding the metadata lock blocking Connection 2, we have a deadlock.
This deadlock would also happen for earlier trees without MDL, but
there DROP DATABASE would wait for a table to be removed from the
table definition cache.
This patch fixes the problem by prohibiting CREATE DATABASE in LOCK TABLES
mode. In the example above, this prevents Connection 1 from hanging trying
to get the LOCK_mysql_create_db mutex. Note that other commands that use
LOCK_mysql_create_db (ALTER/DROP DATABASE) are already prohibited in
LOCK TABLES mode.
Incompatible change: CREATE DATABASE is now disallowed in LOCK TABLES mode.
Test case added to schema.test.
This deadlock would occur between two connections A and B if statements
where executed in the following way:
1) Connection A executes a DML statement against table s1.t1 with
autocommit off. This causes a shared metadata lock on s1.t1 to be
acquired. (With autocommit on, the metadata lock will be dropped once
the statment completes and the deadlock will not occour.)
2) Connection B tries to DROP DATABASE s1. This will block against the
metadata lock connection A holds on s1.t1. While blocking, connection B
will hold the LOCK_mysql_create_db mutex.
3) Connection A tries to ALTER DATABASE s1. This will block when trying
to get LOCK_mysql_create_db mutex held by connection B.
4) Deadlock between DROP DATABASE and ALTER DATABASE (which has autocommit
off).
If Connection A used an explicitly started transaction rather than having
autocommit off, this deadlock did not happen as ALTER DATABASE is
disallowed inside transactions.
This patch fixes the problem by changing ALTER DATABASE to cause an
implicit commit before executing. This will cause the metadata
lock on s1.t1 to be dropped, allowing DROP DATABASE to proceed.
This will in turn cause the LOCK_mysql_create_db mutex to be unlocked,
allowing ALTER DATABASE to proceed.
Note that SQL commands other than ALTER DATABASE that also use
LOCK_mysql_create_db, already cause an implicit commit.
Incompatible change: ALTER DATABASE (and its synonym ALTER SCHEMA)
now cause an implicit commit. This must be reflected in the
documentation.
Test case added to schema.test.
Moved .progress files into the log directory
Moved 'cluster' database tables into the MySQL database, to not have 'cluster' beeing a reserved database name
Fixed bug where mysqld got a core dump when trying to use a table created by MySQL 3.23
Fixed some compiler warnings
Fixed small memory leak in libmysql
Note that this doesn't changeset doesn't include the new mysqldump.c code required to run some tests. This will be added when I merge 5.0 to 5.1
according to the standard.
The idea is to use Field-classes to implement stored routines
variables. Also, we should provide facade to Item-hierarchy
by Item_field class (it is necessary, since SRVs take part
in expressions).
The patch fixes the following bugs:
- BUG#8702: Stored Procedures: No Error/Warning shown for inappropriate data
type matching;
- BUG#8768: Functions: For any unsigned data type, -ve values can be passed
and returned;
- BUG#8769: Functions: For Int datatypes, out of range values can be passed
and returned;
- BUG#9078: STORED PROCDURE: Decimal digits are not displayed when we use
DECIMAL datatype;
- BUG#9572: Stored procedures: variable type declarations ignored;
- BUG#12903: upper function does not work inside a function;
- BUG#13705: parameters to stored procedures are not verified;
- BUG#13808: ENUM type stored procedure parameter accepts non-enumerated
data;
- BUG#13909: Varchar Stored Procedure Parameter always BINARY string (ignores
CHARACTER SET);
- BUG#14161: Stored procedure cannot retrieve bigint unsigned;
- BUG#14188: BINARY variables have no 0x00 padding;
- BUG#15148: Stored procedure variables accept non-scalar values;
