Query_log_event::error_code
A query can perform completely having the local var error of mysql_$query
zero, where $query in insert, update, delete, load,
and be binlogged with error_code e.g KILLED_QUERY while there is no
reason do to so.
That can happen because Query_log_event consults thd->killed flag to
evaluate error_code.
Fixed with implementing a scheme suggested and partly implemented at
time of bug@22725 work-on. error_status is cached immediatly after the
control leaves the main rows-loop and that instance always corresponds
to `error' the local of mysql_$query functions. The cached value
is passed to Query_log_event constructor, not the default thd->killed
which can be changed in between of the caching and the constructing.
similar to bug_27716, but it was stressed on in the synopsis on that there is another
side of the artifact affecting behaviour in transaction.
Fixed with deploying multi_delete::send_error() - otherwise never called - and refining its logic
to perform binlogging job if needed.
The changeset includes the following side effects:
- added tests to check bug_23333's scenarios on the mixture of tables for multi_update;
- fixes bug@30763 with two-liner patch and a test coinciding to one added for bug_23333.
Binlogging of the statement with a side effect like a modified non-trans table did not happen.
The artifact involved all binloggable dml queries.
Fixed with changing the binlogging conditions all over the code to exploit thd->transaction.stmt.modified_non_trans_table
introduced by the patch for bug@27417.
Multi-delete case has own specific addressed by another bug@29136. Multi-update case has been addressed by bug#27716 and
patch and will need merging.
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.
causing wrong error message in Falcon
An error message about a duplicate key could show a wrong key
value when not all columns of the key were used to select the
rows for update.
Some storage engines return a record with only the selected
columns filled.
This is fixed by re-reading the record with a read_set which
includes all columns of the duplicate key after a duplicate key
error happens and before the error message is printed.
When a table is being updated it has two set of fields - fields required for
checks of conditions and fields to be updated. A storage engine is allowed
not to retrieve columns marked for update. Due to this fact records can't
be compared to see whether the data has been changed or not. This makes the
server always update records independently of data change.
Now when an auto-updatable timestamp field is present and server sees that
a table handle isn't going to retrieve write-only fields then all of such
fields are marked as to be read to force the handler to retrieve them.
Sometimes the number of really updated rows (with changed
column values) cannot be determined at the server level
alone (e.g. if the storage engine does not return enough
column values to verify that). So the only dependable way
in such cases is to let the storage engine return that
information if possible.
Fixed the bug at server level by providing a way for the
storage engine to return information about wether it
actually updated the row or the old and the new column
values are the same. It can do that by returning
HA_ERR_RECORD_IS_THE_SAME in ha_update_row().
Note that each storage engine may choose not to try to
return this status code, so this behaviour remains
storage engine specific.
Implementation of mysql_multi_update did not call multi_update::send_error method in some cases
(see the test reported on bug page and test cases in changeset).
Fixed with deploying the method, ::send_error() is refined to get binlogging code which works whenever
there is modified non-transactional table.
thd->no_trans_update.stmt flag is set in to TRUE to ease testing though being the beginning of relative
bug#27417 fix (addresses a part of those issues).
Eliminating two minor issues (small bugs) in multi_update methods.
This patch for multi-update also addresses a part of the issues reported in bug#13270,bug#23333.
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.
The reason for the bug was that replaying of a query on slave could not be possible since its event
was recorded with the killed error. Due to the specific of handling INSERT, which per-row-while-loop is
unbreakable to killing, the query on transactional table should have not appeared in binlog unless
there was a call to a stored routine that got interrupted with killing (and then there must be an error
returned out of the loop).
The offered solution added the following rule for binlogging of INSERT that accounts the above
specifics:
For INSERT on transactional-table if the error was not set the only raised flag
is harmless and is ignored via masking out on time of creation of binlog event.
For both table types the combination of raised error and KILLED flag indicates that there
was potentially partial execution on master and consistency is under the question.
In that case the code continues to binlog an event with an appropriate killed error.
The fix relies on the specified behaviour of stored routine that must propagate the error
to the top level query handling if the thd->killed flag was raised in the routine execution.
The patch adds an arg with the default killed-status-unset value to Query_log_event::Query_log_event.
- 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.
