This is a port of the following changeset from
5.1/storage/innobase to 5.1/storage/innodb_plugin:
------------------------------------------------------------
revno: 3626
revision-id: vasil.dimov@oracle.com-20101013171859-gi9n558yj89x9v3w
parent: klewis@mysql.com-20101012175933-ce9kkgl0z8oeqffa
committer: Vasil Dimov <vasil.dimov@oracle.com>
branch nick: mysql-5.1-innodb
timestamp: Wed 2010-10-13 20:18:59 +0300
message:
Fix Bug#56143 too many foreign keys causes output of show create table to become invalid
Just remove the check whether the file is "too big".
A similar code exists in ha_innobase::update_table_comment() but that
method does not seem to be used.
Also use a CREATE statement with all the FKs instead of ALTERing the
table 550 times because it is faster.
Just remove the check whether the file is "too big".
A similar code exists in ha_innobase::update_table_comment() but that
method does not seem to be used.
Subselect executes twice, at JOIN::optimize stage
and at JOIN::execute stage. At optimize stage
Innodb prebuilt struct which is used for the
retrieval of column values is initialized in.
ha_innobase::index_read(), prebuilt->sql_stat_start is true.
After QUICK_ROR_INTERSECT_SELECT finished his job it
restores read_set/write_set bitmaps with initial values
and deactivates one of the handlers used by
QUICK_ROR_INTERSECT_SELECT in JOIN::cleanup
(it's the case when we reuse original handler as one of
handlers required by QUICK_ROR_INTERSECT_SELECT object).
On second subselect execution inactive handler is activated
in QUICK_RANGE_SELECT::reset, file->ha_index_init().
In ha_index_init Innodb prebuilt struct is reinitialized
with inappropriate read_set/write_set bitmaps. Further
reinitialization in ha_innobase::index_read() does not
happen as prebuilt->sql_stat_start is false.
It leads to partial retrieval of required field values
and we get a mix of field values from different records
in the record buffer.
The fix is to reset
read_set/write_set bitmaps as these values
are required for proper intialization of
internal InnoDB struct which is used for
the retrieval of column values
(see build_template(), ha_innodb.cc)
adding new indexes
A fast alter table requires that the existing (old) table
and indices are unchanged (i.e only new indices can be
added). To verify this, the layout and flags of the old
table/indices are compared for equality with the new.
The PACK_KEYS option is a no-op in InnoDB, but the flag
exists, and is used in the table compare. We need to
check this (table) option flag before deciding whether an
index should be packed or not. If the table has
explicitly set PACK_KEYS to 0, the created indices should
not be marked as packed/packable.
ORDER BY computed col
GROUP BY implies ORDER BY in the MySQL dialect of SQL. Therefore, when an
index on the first table in the query is used, and that index satisfies
ordering according to the GROUP BY clause, the query optimizer estimates the
number of tuples that need to be read from this index. If there is a LIMIT
clause, table statistics on tables following this 'sort table' are employed.
There may be a separate ORDER BY clause however, which mandates reading the
whole 'sort table' anyway. But the previous estimate was left untouched.
Fixed by removing the estimate from EXPLAIN output if GROUP BY is used in
conjunction with an ORDER BY clause that mandates using a temporary table.
Version "5.1.42 SUSE MySQL RPM"
When a query was using a DATE or DATETIME value formatted
using different formatting than "yyyy-mm-dd HH:MM:SS", a
query with a greater-or-equal '>=' condition matched only
greater values in an indexed TIMESTAMP column.
The problem was introduced by the fix for the bug 46362
and partially solved (for DATE and DATETIME columns only)
by the fix for the bug 47925.
The stored_field_cmp_to_item function has been modified
to take into account TIMESTAMP columns like we do for
DATE and DATETIME columns.
result
Row subqueries producing no rows were not handled as UNKNOWN
values in row comparison expressions.
That was a result of the following two problems:
1. Item_singlerow_subselect did not mark the resulting row
value as NULL/UNKNOWN when no rows were produced.
2. Arg_comparator::compare_row() did not take into account that
a whole argument may be NULL rather than just individual scalar
values.
Before bug#34384 was fixed, the above problems were hidden
because an uninitialized (i.e. without any stored value) cached
object would appear as NULL for scalar values in a row subquery
returning an empty result. After the fix
Arg_comparator::compare_row() would try to evaluate
uninitialized cached objects.
Fixed by removing the aforementioned problems.
The EXISTS transformation has additional switches to catch the known corner
cases that appear when transforming an IN predicate into EXISTS. Guarded
conditions are used which are deactivated when a NULL value is seen in the
outer expression's row. When the inner query block supplies NULL values,
however, they are filtered out because no distinction is made between the
guarded conditions; guarded NOT x IS NULL conditions in the HAVING clause that
filter out NULL values cannot be de-activated in isolation from those that
match values or from the outer expression or NULL's.
The above problem is handled by making the guarded conditions remember whether
they have rejected a NULL value or not, and index access methods are taking
this into account as well.
The bug consisted of
1) Not resetting the property for every nested loop iteration on the inner
query's result.
2) Not propagating the NULL result properly from inner query to IN optimizer.
3) A hack that may or may not have been needed at some point. According to a
comment it was aimed to fix#2 by returning NULL when FALSE was actually
the result. This caused failures when #2 was properly fixed. The hack is
now removed.
The fix resolves all three points.
multi-table UPDATE IGNORE.
The problem was that if there was an active SELECT statement
during trigger execution, an error risen during the execution
may cause a crash. The fix is to temporary reset LEX::current_select
before trigger execution and restore it afterwards. This way
errors risen during the trigger execution are processed as
if there was no active SELECT.
inited==INDEX
When an error occurs while sending the data in a temporary table there was no
cleanup performed. This caused a failed assertion in the case when different
access methods were used for populating the table vs. retrieving the data from
the table if IGNORE was specified and sql_safe_updates = 0. In this case
execution continues, but the handler expects to continue with the access
method used for row retrieval.
Fixed by doing the cleanup even if errors occur.
case than in corr index".
Server was unable to find existing or explicitly created supporting
index for foreign key if corresponding statement clause used field
names in case different than one used in key specification and created
yet another supporting index.
In cases when name of constraint (and thus name of generated index)
was the same as name of existing/explicitly created index this led
to duplicate key name error.
The problem was that unlike all other code Key_part_spec::operator==()
compared field names in case sensitive fashion. As result routines
responsible for getting rid of redundant generated supporting indexes
for foreign key were not working properly for versions of field names
using different cases.
(backported from mysql-trunk)
Bug#46754: 'rows' field doesn't reflect partition pruning
The EXPLAIN's result in 'rows' field
was evaluated to number of rows when the table was opened
(not from the table cache) and only the partitions left
after pruning was updated with its correct number
of rows.
The evaluation of the 'rows' field was using handler::records()
which is a potentially expensive call, and ignores the partitioning
pruning.
The fix was to use the handlers stats.records after updating it
with ::info(HA_STATUS_VARIABLE) instead.
"Access compatibility" syntax
The "wild" "DELETE FROM table_name.* ... USING ..." syntax
for multi-table DELETE statements is documented but it was
lost in the fix for the bug 30234.
The table_ident_opt_wild parser rule has been added
to restore the lost syntax.
== MYSQL_TYPE_LONGLONG
A MIN/MAX() function with a subquery as its argument could lead
to a debug assertion on debug builds or wrong data on release
ones.
The problem was a combination of the following factors:
- Item_sum_hybrid::fix_fields() might use the argument
(args[0]) to calculate 'hybrid_field_type' which was later used
to decide how the data should be sent to the client.
- Item_sum::make_field() might use the argument again to
calculate the field's type when sending result set metadata to
the client.
- The argument could be changed in between these two calls via
Item::set_arg() leading to inconsistent metadata being
reported.
Here is what was happening for the bug's test case:
1. Item_sum_hybrid::fix_fields() calculates hybrid_field_type
as MYSQL_TYPE_LONGLONG based on args[0] which is an
Item::SUBSELECT_ITEM at that time.
2. A temporary table is created to execute the
query. create_tmp_field_from_item() creates a Field_long object
according to the subselect's max_length.
3. The subselect item in Item_sum_hybrid is replaced by the
Item_field object referencing the newly created Field_long.
4. Item_sum::make_field() rightfully returns the
MYSQL_TYPE_LONG type when calculating the result set metadata.
5. When sending the actual data, Item::send() relies on the
virtual field_type() function which in our case returns
previously calculated hybrid_field_type == MYSQL_TYPE_LONGLONG.
It looks like the only solution is to never refer to the
argument's metadata after the result metadata has been
calculated in fix_fields(), since the argument itself may be
different by then. In this sense, Item_sum::make_field() should
never be used, because it may rely on the argument's metadata
and is only called after fix_fields(). The "default"
implementation in Item::make_field() should be used instead as
it relies only on field_type(), but not on the argument's type.
Fixed by removing Item_sum::make_field() so that the superclass
implementation Item::make_field() is always used.
After fix for bug 39653 the shortest available secondary index was used for
full table scan. Primary clustered key was used only if no secondary index
can be used. However, when chosen secondary index includes all fields of the
table being scanned it's better to use primary index since the amount of
data to scan is the same but the primary index is clustered.
Now the find_shortest_key function takes this into account.
Queries involving predicates of the form "const NOT BETWEEN
not_indexed_column AND indexed_column" could return wrong data
due to incorrect handling by the range optimizer.
For "c NOT BETWEEN f1 AND f2" predicates, get_mm_tree()
produces a disjunction of the SEL_ARG trees for "f1 > c" and
"f2 < c". If one of the trees is empty (i.e. one of the
arguments is not sargable) the resulting tree should be empty
as well, since the whole expression in this case is not
sargable.
The above logic is implemented in get_mm_tree() as follows. The
initial state of the resulting tree is NULL (aka empty). We
then iterate through arguments and compute the corresponding
SEL_ARG tree (either "f1 > c" or "f2 < c"). If the resulting
tree is NULL, it is simply replaced by the generated
tree. Otherwise it is replaced by a disjunction of itself and
the generated tree. The obvious flaw in this implementation is
that if the first argument is not sargable and thus produces a
NULL tree, the resulting tree will simply be replaced by the
tree for the second argument. As a result, "c NOT BETWEEN f1
AND f2" will end up as just "f2 < c".
Fixed by adding a check so that when the first argument
produces an empty tree for the NOT BETWEEN case, the loop is
aborted with an empty tree as a result. The whole idea of using
a loop for 2 arguments does not make much sense, but it was
probably used to avoid code duplication for several BETWEEN
variants.
'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour
BUG#55474, BUG#55499, BUG#55598, BUG#55616 and BUG#55777 are fixed
in this patch too.
This is the 5.1 part.
It implements:
- if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
and INSERT ... SELECT
- Insert nothing and binlog nothing on master if the existing object
is a view. It only generates a warning that table already exists.
