LOCK TABLES takes a list of tables to lock. It may lock several
tables successfully and then encounter a tables that it can't lock,
e.g. because it's locked. In such case it needs to undo the locks on
the already locked tables. And it does that. But it has also notified
the relevant table storage engine handlers that they should lock.
The only reliable way to ensure that the table handlers will give up
their locks is to end the transaction. This is what UNLOCK TABLE
does : it ends the transaction if there were locked tables by LOCK
tables.
It is possible to end the transaction when the lock fails in
LOCK TABLES because LOCK TABLES ends the transaction at its start
already.
Fixed by ending (again) the transaction when LOCK TABLES fails to
lock a table.
ALTER VIEW is currently not supported as a prepared statement
and should be disabled as such as they otherwise could cause server crashes.
ALTER VIEW is currently not supported when called from stored
procedures or functions for related reasons and should also be disabled.
This patch disables these DDL statements and adjusts the appropriate test
cases accordingly.
Additional tests has been added to reflect on the fact that we do support
CREATE/ALTER/DROP TABLE for Prepared Statements (PS), Stored Procedures (SP)
and PS within SP.
CREATE/DROP TEMPORARY TABLE + ROLLBACK on master
The transaction ability of the storage engines of
the tables on the replication master and the replication
slave must generally be the same.
When the storage engine type of the slave is
non-transactional then transactions on the master that
mix update of transactional and non-transactional tables
should be avoided because they will cause inconsistency of
the data between the master's transactional table and the
slave's non-transactional table.
The effect described by this bug is actually expected.
A detailed test case is added (to be merged later to
the updated rpl_ddl.test), as there was no coverage
by the existing tests.
Some code cleanup is also added by this change.
1. Introduce parse_sql() as a high-level replacement for MYSQLparse().
parse_sql() is responsible to switch and restore "parser context"
(THD::m_lip for now).
2. Fix typo in sp.cc: THD::spcont should be reset *before* calling
the parser.
protocol
Fixed duplicated code, same as last commit.
One could send a malformed packet that caused the server to SEGV. In
recent versions of the password protocol, the client tells the server
what length the ciphertext is (almost always 20). If that length was
large enough to overflow a signed char, then the number would jump to
very large after being casted to unsigned int.
Instead, cast the *passwd char to uchar.
Coding style: classes start with a capital letter.
Rename some classes related to parsing:
create_field -> Create_field
foreign_key -> Foreign_key
key_part_spec -> Key_part_spec
protocol
One could send a malformed packet that caused the server to SEGV. In
recent versions of the password protocol, the client tells the server
what length the ciphertext is (almost always 20). If that length was
large enough to overflow a signed char, then the number would jump to
very large after being casted to unsigned int.
Instead, cast the *passwd char to uchar.
Changed SHOW ENGINES to work in the same way as I_S.ENGINES.
For this: removed the functions mysqld_show_storage_engines and show_handlerton, and
made SHOW ENGINES work via the common function iter_schema_engines.
There in no test case because an engine (except of MyISAM) may be not compiled or disabled
which may affect the test result.
In case of database level grant the database name may be a pattern,
in case of table|column level grant the database name can not be a pattern.
We use 'dont_check_global_grants' as a flag to determine
if it's database level grant command
(see SQLCOM_GRANT case, mysql_execute_command() function) and
set db_is_pattern according to 'dont_check_global_grants' value.
Moving code to check storage engine capabilities to after tables
are locked. Moving code to cache table flags so that table flags
are read from the storage engine at the beginning of the statement
in addition to when the storage engine is opened.
To handle CREATE-SELECT, the decision function is called after the
table is created and it is called with all tables that are in the select
part of the statement as well as the newly created table.
- A race condition caused brief unavailablility when trying to acccess
a table.
- The variable 'grant_option' was removed to resolve the race condition and
to simplify the design pattern. This flag was originally intended to optimize
grant checks.
Bug#4968 ""Stored procedure crash if cursor opened on altered table"
Bug#6895 "Prepared Statements: ALTER TABLE DROP COLUMN does nothing"
Bug#19182 "CREATE TABLE bar (m INT) SELECT n FROM foo; doesn't work from
stored procedure."
Bug#19733 "Repeated alter, or repeated create/drop, fails"
Bug#22060 "ALTER TABLE x AUTO_INCREMENT=y in SP crashes server"
Bug#24879 "Prepared Statements: CREATE TABLE (UTF8 KEY) produces a
growing key length" (this bug is not fixed in 5.0)
Re-execution of CREATE DATABASE, CREATE TABLE and ALTER TABLE
statements in stored routines or as prepared statements caused
incorrect results (and crashes in versions prior to 5.0.25).
In 5.1 the problem occured only for CREATE DATABASE, CREATE TABLE
SELECT and CREATE TABLE with INDEX/DATA DIRECTOY options).
The problem of bugs 4968, 19733, 19282 and 6895 was that functions
mysql_prepare_table, mysql_create_table and mysql_alter_table are not
re-execution friendly: during their operation they modify contents
of LEX (members create_info, alter_info, key_list, create_list),
thus making the LEX unusable for the next execution.
In particular, these functions removed processed columns and keys from
create_list, key_list and drop_list. Search the code in sql_table.cc
for drop_it.remove() and similar patterns to find evidence.
The fix is to supply to these functions a usable copy of each of the
above structures at every re-execution of an SQL statement.
To simplify memory management, LEX::key_list and LEX::create_list
were added to LEX::alter_info, a fresh copy of which is created for
every execution.
The problem of crashing bug 22060 stemmed from the fact that the above
metnioned functions were not only modifying HA_CREATE_INFO structure
in LEX, but also were changing it to point to areas in volatile memory
of the execution memory root.
The patch solves this problem by creating and using an on-stack
copy of HA_CREATE_INFO in mysql_execute_command.
Additionally, this patch splits the part of mysql_alter_table
that analizes and rewrites information from the parser into
a separate function - mysql_prepare_alter_table, in analogy with
mysql_prepare_table, which is renamed to mysql_prepare_create_table.
Don't try determine stack direction at configure time
compiler_flag.m4:
Use AC_TRY_COMPILE and AC_TRY_LINK instead of AC_TRY_RUN where possible
misc.m4, configure.in:
Use fourth argument to AC_TRY_RUN, to be used in cross compilation
Don't try determine stack direction at configure time
