The general log write function (general_log_print) uses printf style
arguments which need to be pre-processed, meaning that the all arguments
are copied to a single buffer and the problem is that the buffer size is
constant (1022 characters) but queries can be much larger then this.
The solution is to introduce a new log write function that accepts a
buffer and it's length as arguments. The function is to be used when
a formatted output is not required, which is the case for almost all
query write-to-log calls.
This is a incompatible change with respect to the log format of prepared
statements.
The problem was that the RETURNS column in the mysql.proc was of
CHAR(64). That was not enough for storing long-named datatypes.
The fix is to change CHAR(64) to LONGBLOB, and to throw warnings
at the time a stored routine is created if some data is truncated
during writing into mysql.proc.
The root cause of the issue was that the CREATE FUNCTION grammar,
for User Defined Functions, was using the sp_name rule.
The sp_name rule is intended for fully qualified stored procedure names,
like either ident.ident, or just ident but with a default database
implicitly selected.
A UDF does not have a fully qualified name, only a name (ident), and should
not use the sp_name grammar fragment during parsing.
The fix is to re-organize the CREATE FUNCTION grammar, to better separate:
- creating UDF (no definer, can have AGGREGATE, simple ident)
- creating Stored Functions (definer, no AGGREGATE, fully qualified name)
With the test case provided, another issue was exposed which is also fixed:
the DROP FUNCTION statement was using sp_name and also failing when no database
is implicitly selected, when droping UDF functions.
The fix is also to change the grammar so that DROP FUNCTION works with
both the ident.ident syntax (to drop a stored function), or just the ident
syntax (to drop either a UDF or a Stored Function, in the current database)
insert_id after succ. mysql_change_user() call.
See also WL 4066.
This bug reveals two problems:
- the problem on the client side which was described originally;
- the problem in protocol / the server side: connection context
on client and server should be like after mysql_real_connect()
and be consistent. The server however just resets character
set variables to the global defaults.
The fix seems to be as follows:
- extend the protocol so that the client be able to send
character set information in COM_CHANGE_USER command;
- change the server so that it understands client character set
in the command;
- change the client:
- reset character set to the default value (which has been
read from the configuration);
- send character set in COM_CHANGE_USER command.
The problem was that aborted_threads variable was updated
twice when a client connection had been aborted.
The fix is to refactor a code to have aborted_threads updated
only in one place.
UPGRADE)
Bug 17565 (RENAME DATABASE destroys events)
Bug#28360 (RENAME DATABASE destroys routines)
Removed the
RENAME DATABASE db1 TO db2
statement.
Implemented the
ALTER DATABASE db UPGRADE DATA DIRECTORY NAME
statement, which has the same function.
When dumping database from a 4.x server, the mysqldump client
inserted a delimiter sign inside special commentaries of the form:
/*!... CREATE DATABASE IF NOT EXISTS ... ;*/
During restoration that dump file was splitten by delimiter signs on
the client side, and the rest of some commentary strings was prepended
to following statements.
The 4x_server_emul test case option has been added for use with the
DBUG_EXECUTE_IF debugging macro. This option affects debug server
builds only to emulate particular behavior of a 4.x server for
the mysqldump client testing. Non-debugging builds are not affected.
Bug#21422 GRANT/REVOKE possible inside stored function, probably in a trigger
Bug#17244 GRANT gives strange error message when used in a stored function
GRANT/REVOKE statements are non-transactional (no explicit transaction
boundaries) in nature and hence are forbidden inside stored functions and
triggers, but they weren't being effectively forbidden. Furthermore, the
absence of implict commits makes changes made by GRANT/REVOKE statements to
not be rolled back.
The implemented fix is to issue a implicit commit with every GRANT/REVOKE
statement, effectively prohibiting these statements in stored functions
and triggers. The implicit commit also fixes the replication bug, and looks
like being in concert with the behavior of DDL and administrative statements.
Since this is a incompatible change, the following sentence should be
added to the Manual in the very end of the 3rd paragraph, subclause
13.4.3 "Statements That Cause an Implicit Commit": "Beginning with
MySQL 5.0.??, the GRANT and REVOKE statements cause an implicit commit."
Patch contributed by Vladimir Shebordaev
The SELECT query with more than 31 nested dependent SELECT queries returned
wrong result.
New error message has been added: ER_TOO_HIGH_LEVEL_OF_NESTING_FOR_SELECT.
It will be reported as: "Too high level of nesting for select".
Problem: thd->thread_specific_used flag is not set executing a statement
containig connection_id() function using PS protocol, that leads to
improper binlog event creation.
Fix: set the flag in the Item_func_connection_id::fix_fields().
Bug #27417 thd->no_trans_update.stmt lost value inside of SF-exec-stack
Once had been set the flag might later got reset inside of a stored routine
execution stack.
The reason was in that there was no check if a new statement started at time
of resetting.
The artifact affects most of binlogable DML queries. Notice, that multi-update
is wrapped up within
bug@27716 fix, multi-delete bug@29136.
Fixed with saving parent's statement flag of whether the statement modified
non-transactional table, and unioning (merging) the value with that was gained
in mysql_execute_command.
Resettling thd->no_trans_update members into thd->transaction.`member`;
Asserting code;
Effectively the following properties are held.
1. At the end of a substatement thd->transaction.stmt.modified_non_trans_table
reflects the fact if such a table got modified by the substatement.
That also respects THD::really_abort_on_warnin() requirements.
2. Eventually thd->transaction.stmt.modified_non_trans_table will be computed as
the union of the values of all invoked sub-statements.
That fixes this bug#27417;
Computing of thd->transaction.all.modified_non_trans_table is refined to base to
the stmt's value for all the case including insert .. select statement which
before the patch had an extra issue bug@28960.
Minor issues are covered with mysql_load, mysql_delete, and binloggin of insert in
to temp_table select.
The supplied test verifies limitely, mostly asserts. The ultimate testing is defered
for bug@13270, bug@23333.
--long-query-time is now given in seconds with microseconds as decimals
--min_examined_row_limit added for slow query log
long_query_time user variable is now double with 6 decimals
Added functions to get time in microseconds
Added faster time() functions for system that has gethrtime() (Solaris)
We now do less time() calls.
Added field->in_read_set() and field->in_write_set() for easier field manipulation by handlers
set_var.cc and my_getopt() can now handle DOUBLE variables.
All time() calls changed to my_time()
my_time() now does retry's if time() call fails.
Added debug function for stopping in mysql_admin_table() when tables are locked
Some trivial function and struct variable renames to avoid merge errors.
Fixed compiler warnings
Initialization of some time variables on windows moved to my_init()
Bug#25422 (Hang with log tables)
Bug 17876 (Truncating mysql.slow_log in a SP after using cursor locks the
thread)
Bug 23044 (Warnings on flush of a log table)
Bug 29129 (Resetting general_log while the GLOBAL READ LOCK is set causes
a deadlock)
Prior to this fix, the server would hang when performing concurrent
ALTER TABLE or TRUNCATE TABLE statements against the LOG TABLES,
which are mysql.general_log and mysql.slow_log.
The root cause traces to the following code:
in sql_base.cc, open_table()
if (table->in_use != thd)
{
/* wait_for_condition will unlock LOCK_open for us */
wait_for_condition(thd, &LOCK_open, &COND_refresh);
}
The problem with this code is that the current implementation of the
LOGGER creates 'fake' THD objects, like
- Log_to_csv_event_handler::general_log_thd
- Log_to_csv_event_handler::slow_log_thd
which are not associated to a real thread running in the server,
so that waiting for these non-existing threads to release table locks
cause the dead lock.
In general, the design of Log_to_csv_event_handler does not fit into the
general architecture of the server, so that the concept of general_log_thd
and slow_log_thd has to be abandoned:
- this implementation does not work with table locking
- it will not work with commands like SHOW PROCESSLIST
- having the log tables always opened does not integrate well with DDL
operations / FLUSH TABLES / SET GLOBAL READ_ONLY
With this patch, the fundamental design of the LOGGER has been changed to:
- always open and close a log table when writing a log
- remove totally the usage of fake THD objects
- clarify how locking of log tables is implemented in general.
See WL#3984 for details related to the new locking design.
Additional changes (misc bugs exposed and fixed):
1)
mysqldump which would ignore some tables in dump_all_tables_in_db(),
but forget to ignore the same in dump_all_views_in_db().
2)
mysqldump would also issue an empty "LOCK TABLE" command when all the tables
to lock are to be ignored (numrows == 0), instead of not issuing the query.
3)
Internal errors handlers could intercept errors but not warnings
(see sql_error.cc).
4)
Implementing a nested call to open tables, for the performance schema tables,
exposed an existing bug in remove_table_from_cache(), which would perform:
in_use->some_tables_deleted=1;
against another thread, without any consideration about thread locking.
This call inside remove_table_from_cache() was not required anyway,
since calling mysql_lock_abort() takes care of aborting -- cleanly -- threads
that might hold a lock on a table.
This line (in_use->some_tables_deleted=1) has been removed.
