The problem becomes apparent only if HAVE_purify is undefined.
It related to the part of code placed in open_table_from_share() fuction
where we initialize record buffer only if HAVE_purify is enabled.
So in case of HAVE_purify=OFF record buffer is not initialized
on open table stage.
Next we read key, find NULL value and update appropriate null bit
but do not update record buffer. After that the record is stored
in the join cache(store_record_in_cache). For CHAR fields we
strip trailing spaces and in our case this procedure uses
uninitialized record buffer.
The fix is to skip stripping space procedure in case of null values
for CHAR fields(partially based on 6.0 JOIN_CACHE implementation).
error causes debug assertion
The IGNORE option of the multiple-table UPDATE command was
not intended to suppress errors caused by the
sql_safe_updates mode. This flag will raise an error if the
execution of UPDATE does not use a key for row retrieval,
and should continue do so regardless of the IGNORE option.
However the implementation of IGNORE does not support
exceptions to the rule; it always converts errors to
warnings and cannot be extended. The Internal_error_handler
interface offers the infrastructure to handle individual
errors, making sure that the error raised by
sql_safe_updates is not silenced.
Fixed by implementing an Internal_error_handler and using it
for UPDATE IGNORE commands.
removed in MySQL 6.0
CREATE TABLE... TYPE= returns the warning "The syntax
'TYPE=storage_engine' is deprecated and will be removed in
MySQL 6.0. Please use 'ENGINE=storage_engine' instead"
This syntax is deprecated already from version 5.4.4, so
the message has been changed.
In addition, the deprecation macro was changed to reflect
the ServerPT decision not to include version number in the
warning message.
A number of test result files have been changed as a
consequence of the change in the deprecation macro.
Queries optimized with GROUP_MIN_MAX didn't cleanup KEYREAD
optimization properly. As a result subsequent queries may
return incomplete rows (fields are initialized to default
values).
Grouping by a subquery in a query with a distinct aggregate
function lead to a wrong result (wrong and unordered
grouping values).
There are two related problems:
1) The query like this:
SELECT (SELECT t1.a) aa, COUNT(DISTINCT b) c
FROM t1 GROUP BY aa
returned wrong result, because the outer reference "t1.a"
in the subquery was substituted with the Item_ref item.
The Item_ref item obtains data from the result_field object
that refreshes once after the end of each group. This data
is not applicable to filesort since filesort() doesn't care
about groups (and doesn't update result_field objects with
copy_fields() and so on). Also that data is not applicable
to group separation algorithm: end_send_group() checks every
record with test_if_group_changed() that evaluates Item_ref
items, but it refreshes those Item_ref-s only after the end
of group, that is a vicious circle and the grouped column
values in the output are shifted.
Fix: if
a) we grouping by a subquery and
b) that subquery has outer references to FROM list
of the grouping query,
then we substitute these outer references with
Item_direct_ref like references under aggregate
functions: Item_direct_ref obtains data directly
from the current record.
2) The query with a non-trivial grouping expression like:
SELECT (SELECT t1.a) aa, COUNT(DISTINCT b) c
FROM t1 GROUP BY aa+0
also returned wrong result, since JOIN::exec() substitutes
references to top-level aliases in SELECT list with Item_copy
caching items. Item_copy items have same refreshing policy
as Item_ref items, so the whole groping expression with
Item_copy inside returns wrong result in filesort() and
end_send_group().
Fix: include aliased items into GROUP BY item tree instead
of Item_ref references to them.
logging is disabled
The server would hit an assertion because of a DBUG violation.
There was a missing DBUG_RETURN and instead a plain return
was used.
This patch replaces the return with DBUG_RETURN.
Performing fulltext prefix search (a word with truncation
operator) may cause a dead-loop. ft_min_word_len value
doesn't matter actually.
The problem was introduced along with "smarter index merge"
optimization.
Fixed 2 problems :
1. test_if_order_by_key() was continuing on the primary key
as if it has a primary key suffix (as the secondary keys do).
This leads to crashes in ORDER BY <pk>,<pk>.
Fixed by not treating the primary key as the secondary one
and not depending on it being clustered with a primary key.
2. The cost calculation was trying to read the records
per key when operating on ORDER BYs that order on all of the
secondary key + some of the primary key.
This leads to crashes because of out-of-bounds array access.
Fixed by assuming we'll find 1 record per key in such cases.
Detailed revision comments:
r6489 | sunny | 2010-01-21 02:57:50 +0200 (Thu, 21 Jan 2010) | 2 lines
branches/5.1: Factor out test for bug#44030 from innodb-autoinc.test
into a separate test/result files.
Detailed revision comments:
r6488 | sunny | 2010-01-21 02:55:08 +0200 (Thu, 21 Jan 2010) | 2 lines
branches/5.1: Factor out test for bug#44030 from innodb-autoinc.test
into a separate test/result files.
Several items said to be deprecated in the 4.1 manual
have never been removed. This worklog adds deprecation
warnings when these items are used, and warns the user
that the items will be removed in MySQL 5.6.
A couple of previously deprecation decision have been
reversed (see single file comments)
subselect_single_select_engine::exec()
When a subquery doesn't need to be evaluated because
it returns only aggregate functions and these aggregates
can be calculated from the metadata about the table it
was not updating all the relevant members of the JOIN
structure to reflect that this is a constant query.
This caused problems to the enclosing subquery
('<> SOME' in the test case above) trying to read some
data about the tables.
Fixed by setting const_tables to the number of tables
when the SELECT is optimized away.
REORGANIZE PARTITION
There were several problems which lead to this this,
all related to bad error handling.
1) There was several bugs preventing the ddl-log to be used for
cleaning up created files on error.
2) The error handling after the copy partition rows did not close
and unlock the tables, resulting in deletion of partitions
which were in use, which lead InnoDB to put the partition to
drop in a background queue.
error in the query.
Fixes a leak after materializing a GROUP BY subquery to a
temp table when the subquery has a blob column in the SELECT
list.
Fixed by correctly destructing temporary buffers after doing
the conversion.
'CREATE TABLE IF NOT EXISTS ... SELECT' statement were causing 'CREATE
TEMPORARY TABLE ...' to be written to the binary log in row-based
mode (a.k.a. RBR), when there was a temporary table with the same name.
Because the 'CREATE TABLE ... SELECT' statement was executed as
'INSERT ... SELECT' into the temporary table. Since in RBR mode no
other statements related to temporary tables are written into binary log,
this sometimes broke replication.
This patch changes behavior of 'CREATE TABLE [IF NOT EXISTS] ... SELECT ...'.
it ignores existence of temporary table with the
same name as table being created and is interpreted
as attempt to create/insert into base table. This makes behavior of
'CREATE TABLE [IF NOT EXISTS] ... SELECT' consistent with
how ordinary 'CREATE TABLE' and 'CREATE TABLE ... LIKE' behave.
Selecting of the CONCAT_WS(...<PS parameter>...) result into
a user variable may return wrong data.
Item_func_concat_ws::val_str contains a number of memory
allocation-saving optimization tricks. After the fix
for bug 46815 the control flow has been changed to a
branch that is commented as "This is quite uncommon!":
one of places where we are trying to concatenate
strings inplace. However, that "uncommon" place
didn't care about PS parameters, that have another
trick in Item_sp_variable::val_str(): they use the
intermediate Item_sp_variable::str_value field,
where they may store a reference to an external
argument's buffer.
The Item_func_concat_ws::val_str function has been
modified to take into account val_str functions
(such as Item_sp_variable::val_str) that return a
pointer to an internal Item member variable that
may reference to a buffer provided.
MySQL handles the join syntax "JOIN ... USING( field1,
... )" and natural joins by building the same parse tree as
a corresponding join with an "ON t1.field1 = t2.field1 ..."
expression would produce. This parse tree was not cleaned up
properly in the following scenario. If a thread tries to
lock some tables and finds that the tables were dropped and
re-created while waiting for the lock, it cleans up column
references in the statement by means a per-statement free
list. But if the statement was part of a stored procedure,
column references on the stored procedure's free list weren't
cleaned up and thus contained pointers to freed objects.
Fixed by adding a call to clean up the current prepared
statement's free list.
flush_cached_records() was not correctly checking for errors after calling
Item::val_xxx() methods. The expressions may contain subqueries
or stored procedures that cause errors that should stop the statement.
Fixed by correctly checking for errors and propagating them up the call stack.
error in the query.
Fixes a leak after materializing a GROUP BY subquery to a
temp table when the subquery has a blob column in the SELECT
list.
Fixed by correctly destructing temporary buffers for re-usable
queries
check_access() returning false for a database does not
guarantee that the access is granted to it.
This wrong condition in filling the INFORMATION_SCHEMA
tables causes extra tables to be returned to the user
even if he has no rights to see them.
Fixed by correcting the condition.
fulltext search and row op.
The search for fulltext indexes is searching for some special
predicate layouts. While doing so it's not checking for the number
of columns of the expressions it tries to calculate.
And since row expressions can't return a single scalar value there
was a crash.
Fixed by checking if the expressions are scalar (in addition to
being constant) before calling Item::val_xxx() methods.
column is used for ORDER BY
Problem: filesort isn't meant for null length sort data
(e.g. char(0)), that leads to a server crash.
Fix: disregard sort order if sort data record length is 0 (nothing
to sort).
in multitable delete/subquery
SQL_BUFFER_RESULT should not have an effect on non-SELECT
statements according to our documentation.
Fixed by not passing it through to multi-table DELETE (similarly
to how it's done for multi-table UPDATE).
In statement-based or mixed-mode replication, use DROP TEMPORARY TABLE
to drop multiple tables causes different errors on master and slave,
when one or more of these tables do not exist. Because when executed
on slave, it would automatically add IF EXISTS to the query to ignore
all ER_BAD_TABLE_ERROR errors.
To fix the problem, do not add IF EXISTS when executing DROP TEMPORARY
TABLE on the slave, and clear the ER_BAD_TABLE_ERROR error after
execution if the query does not expect any errors.
Problem was when calculating the range of partitions for
pruning.
Solution was to get the calculation correct. I also simplified
it a bit for easier understanding.
Several problems fixed :
1. Non constant expressions in UNION ... ORDER BY were not correctly cleaned up
in st_select_lex_unit::cleanup() causing crashes in EXPLAIN EXTENDED because of
fields quoted by these expressions pointing to the already freed temporary table
used to calculate the UNION.
Fixed by correctly cleaning up expressions of any depth.
2. Subqueries in the order by part of UNION ... ORDER BY ... caused a crash in
EXPLAIN EXTENDED because of a transformation attempt made during EXPLAIN EXTENDED
execution. Fixed by not doing the transformation when in EXPLAIN.
3. Fulltext functions caused crash when in the ORDER BY part of an un-parenthesized
UNION that gets "promoted" to be valid for the whole union, e.g.
SELECT * FROM t1 UNION SELECT * FROM t2 ORDER BY MATCHES (a) AGAINST ('abc' IN BOOLEAN MODE).
This is a case that demonstrates a more general problem of parts of the query being
moved to another level. When doing such transformation late in the optimization run
when most of the flags about the contents of the query are already aggregated it's possible
to "split" the flags so that they correctly reflect the new queries after the transformation.
In specific the ST_SELECT_LEX::ftfunc_list is holding all the free text function for all the
parts of the second SELECT in the UNION and we don't know what part of that is in the ORDER BY
that we're to move to the UNION level and what part is about the other parts of the second SELECT.
Fixed by throwing and error when such statements are about to be processed by adding a check
for the presence of MATCH() inside the ORDER BY clause that's going to get promoted to UNION.
To workaround this new limitation one must parenthesize the UNION SELECTs and provide a real
global ORDER BY for the UNION outside of the parenthesis.
At the end of execution top level join execution
we cleanup this join with true argument.
It leads to underlying join cleanup(subquery) with true argument too
and to tmp_table_param->field array cleanup which is required later.
The problem is that Item_func_set_user_var does not set
result_filed which leads to unnecessary repeated excution of subquery
on final stage.
The fix is to set result_field for Item_func_set_user_var.
on re-execution of prepared statement
Problem: some (see eq_ref_table()) ORDER BY/GROUP BY optimization
is called before each PS execution. However, we don't properly
initialize its stucture every time before the call.
Fix: properly initialize the sturture used.
freezes (win) the server
The check for equality was assuming the field object is always
created. If it's not it was de-referencing a NULL pointer.
Fixed to use the data in the create object instead.
