The result of the CHECK OPTION condition evaluation over an
updated record and records of merged tables was arbitrary and
dependant on the order of records in the merged tables during
the execution of SELECT statement.
The CHECK OPTION expression was evaluated over expired record
buffers (with arbitrary data in the fields).
Rowids of tables used in the CHECK OPTION expression were
added to temporary table rows. The multi_update::do_updates()
method was modified to restore necessary record buffers
before evaluation of the CHECK OPTION condition.
database.
If a user has a right to update anything in the current database then the
access was granted and further checks of access rights for underlying tables
wasn't done correctly. The check is done before a view is opened and thus no
check of access rights for underlying tables can be carried out.
This allows a user to update through a view a table from another database for
which he hasn't enough rights.
Now the mysql_update() and the mysql_test_update() functions are forces
re-checking of access rights after a view is opened.
In multi_update::send_data(), the counter of matched rows was not correctly incremented, when during insertion of a new row to a temporay table it had to be converted from HEAP to MyISAM.
This fix changes the logic to increment the counter of matched rows in the following cases:
1. If the error returned from write_row() is zero.
2. If the error returned from write_row() is non-zero, is neither HA_ERR_FOUND_DUPP_KEY nor HA_ERR_FOUND_DUPP_UNIQUE, and a call to create_myisam_from_heap() succeeds.
In certain cases AFTER UPDATE/DELETE triggers on NDB tables that referenced
subject table didn't see the results of operation which caused invocation
of those triggers. In other words AFTER trigger invoked as result of update
(or deletion) of particular row saw version of this row before update (or
deletion).
The problem occured because NDB handler in those cases postponed actual
update/delete operations to be able to perform them later as one batch.
This fix solves the problem by disabling this optimization for particular
operation if subject table has AFTER trigger for this operation defined.
To achieve this we introduce two new flags for handler::extra() method:
HA_EXTRA_DELETE_CANNOT_BATCH and HA_EXTRA_UPDATE_CANNOT_BATCH.
These are called if there exists AFTER DELETE/UPDATE triggers during a
statement that potentially can generate calls to delete_row()/update_row().
This includes multi_delete/multi_update statements as well as insert statements
that do delete/update as part of an ON DUPLICATE statement.
thd->options' OPTION_STATUS_NO_TRANS_UPDATE bit was not restored at the end of SF() invocation, where
SF() modified non-ta table.
As the result of this artifact it was not possible to detect whether there were any side-effects when
top-level query ends.
If the top level query table was not modified and the bit is lost there would be no binlogging.
Fixed with preserving the bit inside of thd->no_trans_update struct. The struct agregates two bool flags
telling whether the current query and the current transaction modified any non-ta table.
The flags stmt, all are dropped at the end of the query and the transaction.
Bug 18914 (Calling certain SPs from triggers fail)
Bug 20713 (Functions will not not continue for SQLSTATE VALUE '42S02')
Bug 21825 (Incorrect message error deleting records in a table with a
trigger for inserting)
Bug 22580 (DROP TABLE in nested stored procedure causes strange dependency
error)
Bug 25345 (Cursors from Functions)
This fix resolves a long standing issue originally reported with bug 8407,
which affect the behavior of Stored Procedures, Stored Functions and Trigger
in many different ways, causing symptoms reported by all the bugs listed.
In all cases, the root cause of the problem traces back to 8407 and how the
server locks tables involved with sub statements.
Prior to this fix, the implementation of stored routines would:
- compute the transitive closure of all the tables referenced by a top level
statement
- open and lock all the tables involved
- execute the top level statement
"transitive closure of tables" means collecting:
- all the tables,
- all the stored functions,
- all the views,
- all the table triggers
- all the stored procedures
involved, and recursively inspect these objects definition to find more
references to more objects, until the list of every object referenced does
not grow any more.
This mechanism is known as "pre-locking" tables before execution.
The motivation for locking all the tables (possibly) used at once is to
prevent dead locks.
One problem with this approach is that, if the execution path the code
really takes during runtime does not use a given table, and if the table is
missing, the server would not execute the statement.
This in particular has a major impact on triggers, since a missing table
referenced by an update/delete trigger would prevent an insert trigger to run.
Another problem is that stored routines might define SQL exception handlers
to deal with missing tables, but the server implementation would never give
user code a chance to execute this logic, since the routine is never
executed when a missing table cause the pre-locking code to fail.
With this fix, the internal implementation of the pre-locking code has been
relaxed of some constraints, so that failure to open a table does not
necessarily prevent execution of a stored routine.
In particular, the pre-locking mechanism is now behaving as follows:
1) the first step, to compute the transitive closure of all the tables
possibly referenced by a statement, is unchanged.
2) the next step, which is to open all the tables involved, only attempts
to open the tables added by the pre-locking code, but silently fails without
reporting any error or invoking any exception handler is the table is not
present. This is achieved by trapping internal errors with
Prelock_error_handler
3) the locking step only locks tables that were successfully opened.
4) when executing sub statements, the list of tables used by each statements
is evaluated as before. The tables needed by the sub statement are expected
to be already opened and locked. Statement referencing tables that were not
opened in step 2) will fail to find the table in the open list, and only at
this point will execution of the user code fail.
5) when a runtime exception is raised at 4), the instruction continuation
destination (the next instruction to execute in case of SQL continue
handlers) is evaluated.
This is achieved with sp_instr::exec_open_and_lock_tables()
6) if a user exception handler is present in the stored routine, that
handler is invoked as usual, so that ER_NO_SUCH_TABLE exceptions can be
trapped by stored routines. If no handler exists, then the runtime execution
will fail as expected.
With all these changes, a side effect is that view security is impacted, in
two different ways.
First, a view defined as "select stored_function()", where the stored
function references a table that may not exist, is considered valid.
The rationale is that, because the stored function might trap exceptions
during execution and still return a valid result, there is no way to decide
when the view is created if a missing table really cause the view to be invalid.
Secondly, testing for existence of tables is now done later during
execution. View security, which consist of trapping errors and return a
generic ER_VIEW_INVALID (to prevent disclosing information) was only
implemented at very specific phases covering *opening* tables, but not
covering the runtime execution. Because of this existing limitation,
errors that were previously trapped and converted into ER_VIEW_INVALID are
not trapped, causing table names to be reported to the user.
This change is exposing an existing problem, which is independent and will
be resolved separately.
When INSERT is done over a view the table being inserted into is
checked to be unique among all views tables. But if the view contains
self-joined table an error will be thrown even if all tables are used under
different aliases.
The unique_table() function now also checks tables' aliases when needed.
created for sorting.
Any outer reference in a subquery was represented by an Item_field object.
If the outer select employs a temporary table all such fields should be
replaced with fields from that temporary table in order to point to the
actual data. This replacement wasn't done and that resulted in a wrong
subquery evaluation and a wrong result of the whole query.
Now any outer field is represented by two objects - Item_field placed in the
outer select and Item_outer_ref in the subquery. Item_field object is
processed as a normal field and the reference to it is saved in the
ref_pointer_array. Thus the Item_outer_ref is always references the correct
field. The original field is substituted for a reference in the
Item_field::fix_outer_field() function.
New function called fix_inner_refs() is added to fix fields referenced from
inner selects and to fix references (Item_ref objects) to these fields.
The new Item_outer_ref class is a descendant of the Item_direct_ref class.
It additionally stores a reference to the original field and designed to
behave more like a field.
View check option clauses were ignored for updates of multi-table
views when the updates could not be performed on fly and the rows
to update had to be put into temporary tables first.
updated.
INSERT ... ON DUPLICATE KEY UPDATE reports that a record was updated when
the duplicate key occurs even if the record wasn't actually changed
because the update values are the same as those in the record.
Now the compare_record() function is used to check whether the record was
changed and the update of a record reported only if the record differs
from the original one.
After fix for bug#21798 JOIN stores the pointer to the buffer for sorting
fields. It is used while sorting for grouping and for ordering. If ORDER BY
clause has more elements then the GROUP BY clause then a memory overrun occurs.
Now the length of the ORDER BY list is always passed to the
make_unireg_sortorder() function and it allocates buffer big enough to be
used for bigger list.
Corrected spelling in copyright text
Makefile.am:
Don't update the files from BitKeeper
Many files:
Removed "MySQL Finland AB & TCX DataKonsult AB" from copyright header
Adjusted year(s) in copyright header
Many files:
Added GPL copyright text
Removed files:
Docs/Support/colspec-fix.pl
Docs/Support/docbook-fixup.pl
Docs/Support/docbook-prefix.pl
Docs/Support/docbook-split
Docs/Support/make-docbook
Docs/Support/make-makefile
Docs/Support/test-make-manual
Docs/Support/test-make-manual-de
Docs/Support/xwf
An update that used a join of a table to itself and modified the
table on one side of the join reported the table as crashed or
updated wrong rows.
Fixed by creating temporary table for self-joined multi update statement.
- Removed not used variables and functions
- Added #ifdef around code that is not used
- Renamed variables and functions to avoid conflicts
- Removed some not used arguments
Fixed some class/struct warnings in ndb
Added define IS_LONGDATA() to simplify code in libmysql.c
I did run gcov on the changes and added 'purecov' comments on almost all lines that was not just variable name changes
Fixed compiler warnings (detected by VC++):
- Removed not used variables
- Added casts
- Fixed wrong assignments to bool
- Fixed wrong calls with bool arguments
- Added missing argument to store(longlong), which caused wrong store method to be called.
(Mostly in DBUG_PRINT() and unused arguments)
Fixed bug in query cache when used with traceing (--with-debug)
Fixed memory leak in mysqldump
Removed warnings from mysqltest scripts (replaced -- with #)
list using a function
When executing dependent subqueries they are re-inited and re-exec() for
each row of the outer context.
The cause for the bug is that during subquery reinitialization/re-execution,
the optimizer reallocates JOIN::join_tab, JOIN::table in make_simple_join()
and the local variable in 'sortorder' in create_sort_index(), which is
allocated by make_unireg_sortorder().
Care must be taken not to allocate anything into the thread's memory pool
while re-initializing query plan structures between subquery re-executions.
All such items mush be cached and reused because the thread's memory pool
is freed at the end of the whole query.
Note that they must be cached and reused even for queries that are not
otherwise cacheable because otherwise it will grow the thread's memory
pool every time a cacheable query is re-executed.
We provide additional members to the JOIN structure to store references
to the items that need to be cached.
Note: bug#21726 does not directly apply to 4.1, as it doesn't have stored
procedures. However, 4.1 had some bugs that were fixed in 5.0 by the
patch for bug#21726, and this patch is a backport of those fixes.
Namely, in 4.1 it fixes:
- LAST_INSERT_ID(expr) didn't return value of expr (4.1 specific).
- LAST_INSERT_ID() could return the value generated by current
statement if the call happens after the generation, like in
CREATE TABLE t1 (i INT AUTO_INCREMENT PRIMARY KEY, j INT);
INSERT INTO t1 VALUES (NULL, 0), (NULL, LAST_INSERT_ID());
- Redundant binary log LAST_INSERT_ID_EVENTs could be generated.
Though this is not storage engine specific problem, I was able to
repeat this problem with BDB and NDB engines only. That was the
reason to add a test case into ndb_update.test. As a result
different bad things could happen.
BDB has removed duplicate rows which is not expected.
NDB returns an error.
For multi table update notify storage engine about UPDATE IGNORE
as it is done in single table UPDATE.
Non-upper-level INSERTs (the ones in the body of stored procedure,
stored function, or trigger) into a table that have AUTO_INCREMENT
column didn't affected the result of LAST_INSERT_ID() on this level.
The problem was introduced with the fix of bug 6880, which in turn was
introduced with the fix of bug 3117, where current insert_id value was
remembered on the first call to LAST_INSERT_ID() (bug 3117) and was
returned from that function until it was reset before the next
_upper-level_ statement (bug 6880).
The fix for bug#21726 brings back the behaviour of version 4.0, and
implements the following: remember insert_id value at the beginning
of the statement or expression (which at that point equals to
the first insert_id value generated by the previous statement), and
return that remembered value from LAST_INSERT_ID() or @@LAST_INSERT_ID.
Thus, the value returned by LAST_INSERT_ID() is not affected by values
generated by current statement, nor by LAST_INSERT_ID(expr) calls in
this statement.
Version 5.1 does not have this bug (it was fixed by WL 3146).
this key does not stop" (version for 5.0 only).
UPDATE statement which WHERE clause used key and which invoked trigger
that modified field in this key worked indefinetely.
This problem occured because in cases when UPDATE statement was
executed in update-on-the-fly mode (in which row is updated right
during evaluation of select for WHERE clause) the new version of
the row became visible to select representing WHERE clause and was
updated again and again.
We already solve this problem for UPDATE statements which does not
invoke triggers by detecting the fact that we are going to update
field in key used for scanning and performing update in two steps,
during the first step we gather information about the rows to be
updated and then doing actual updates. We also do this for
MULTI-UPDATE and in its case we even detect situation when such
fields are updated in triggers (actually we simply assume that
we always update fields used in key if we have before update
trigger).
The fix simply extends this check which is done in check_if_key_used()/
QUICK_SELECT_I::check_if_keys_used() routine/method in such way that
it also detects cases when field used in key is updated in trigger.
As nice side-effect we have more precise and thus more optimal
perfomance-wise check for the MULTI-UPDATE.
Also check_if_key_used()/QUICK_SELECT_I::check_if_keys_used() were
renamed to is_key_used()/QUICK_SELECT_I::is_keys_used() in order to
better reflect that boolean predicate.
Note that this check is implemented in much more elegant way in 5.1
containing a select statement that uses an aggregating IN subquery.
Added a parameter to the function fix_prepare_information
to restore correctly the having clause for the second execution.
Saved andor structure of the having conditions at the proper moment
before any calls of split_sum_func2 that could modify the having structure
adding new Item_ref objects. (These additions, are produced not with
the statement mem_root, but rather with the execution mem_root.)
SELECT right instead of INSERT right was required for an insert into to a view.
This wrong behaviour appeared after the fix for bug #20989. Its intention was
to ask only SELECT right for all tables except the very first for a complex
INSERT query. But that patch has done it in a wrong way and lead to asking
a wrong access right for an insert into a view.
The setup_tables_and_check_access() function now accepts two want_access
parameters. One will be used for the first table and the second for other
tables.
privileges
This problem is 4.1 specific. It doesn't affect 4.0 and was fixed
in 5.x before.
Having any mysql user who is allowed to issue multi table update
statement and any column/table grants, allows this user to update
any table on a server (mysql grant tables are not exception).
check_grant() accepts number of tables (in table list) to be checked
in 5-th param. While checking grants for multi table update, number
of tables must be 1. It must never be 0 (actually we have
DBUG_ASSERT(number > 0) in 5.x in grant_check() function).
NDB table".
SQL-layer was not marking fields which were used in triggers as such. As
result these fields were not always properly retrieved/stored by handler
layer. So one might got wrong values or lost changes in triggers for NDB,
Federated and possibly InnoDB tables.
This fix solves the problem by marking fields used in triggers
appropriately.
Also this patch contains the following cleanup of ha_ndbcluster code:
We no longer rely on reading LEX::sql_command value in handler in order
to determine if we can enable optimization which allows us to handle REPLACE
statement in more efficient way by doing replaces directly in write_row()
method without reporting error to SQL-layer.
Instead we rely on SQL-layer informing us whether this optimization
applicable by calling handler::extra() method with
HA_EXTRA_WRITE_CAN_REPLACE flag.
As result we no longer apply this optimzation in cases when it should not
be used (e.g. if we have on delete triggers on table) and use in some
additional cases when it is applicable (e.g. for LOAD DATA REPLACE).
Finally this patch includes fix for bug#20728 "REPLACE does not work
correctly for NDB table with PK and unique index".
This was yet another problem which was caused by improper field mark-up.
During row replacement fields which weren't explicity used in REPLACE
statement were not marked as fields to be saved (updated) so they have
retained values from old row version. The fix is to mark all table
fields as set for REPLACE statement. Note that in 5.1 we already solve
this problem by notifying handler that it should save values from all
fields only in case when real replacement happens.
