columns without where/group
Simple SELECT with implicit grouping used to return many rows if
the query was ordered by the aggregated column in the SELECT
list. This was incorrect because queries with implicit grouping
should only return a single record.
The problem was that when JOIN:exec() decided if execution needed
to handle grouping, it was assumed that sum_func_count==0 meant
that there were no aggregate functions in the query. This
assumption was not correct in JOIN::exec() because the aggregate
functions might have been optimized away during JOIN::optimize().
The reason why queries without ordering behaved correctly was
that sum_func_count is only recalculated if the optimizer chooses
to use temporary tables (which it does in the ordered case).
Hence, non-ordered queries were correctly treated as grouped.
The fix for this bug was to remove the assumption that
sum_func_count==0 means that there is no need for grouping. This
was done by introducing variable "bool implicit_grouping" in the
JOIN object.
The problem was in incorrect handling of predicates involving
NULL as a constant value by the range optimizer.
For example, when creating a SEL_ARG node from a condition of
the form "field < const" (which would normally result in the
"NULL < field < const" SEL_ARG), the special case when "const"
is NULL was not taken into account, so "NULL < field < NULL"
was produced for the "field < NULL" condition.
As a result, SEL_ARG structures of this form could not be
further optimized which in turn could lead to incorrectly
constructed SEL_ARG trees. In particular, code assuming SEL_ARG
structures to always form a sequence of ordered disjoint
intervals could enter an infinite loop under some
circumstances.
Fixed by changing get_mm_leaf() so that for any sargable
predicate except "<=>" involving NULL as a constant, "empty"
SEL_ARG is returned, since such a predicate is always false.
In MySQL when the mapping for space is changed to something other than
0x20 by defining a different collation, then space is not ignored when
comparing two strings.
This was happening because the function that performs the comparison
of two strings while ignoring ending spaces, was comparing the collation
value of a space with the ascii value of the ' ' character. This should
be changed to do comparison between the collated values.
low myisam_sort_buffer_size
Repair by sort (default) or parallel repair of a MyISAM table
(doesn't matter partitioned or not) as well as bulk inserts
and enable indexes some times didn't failover to repair with
key cache.
The problem was that after unsuccessful attempt, data file was
closed. Whereas repair with key cache requires open data file.
Fixed by reopening data file.
Also fixed a valgrind warning, which may appear during repair
by sort or parallel repair with certain myisam_sort_buffer_size
number of rows and length of an index entry (very dependent).
covering index
When two range predicates were combined under an OR
predicate, the algorithm tried to merge overlapping ranges
into one. But the case when a range overlapped several other
ranges was not handled. This lead to
1) ranges overlapping, which gave repeated results and
2) a range that overlapped several other ranges was cut off.
Fixed by
1) Making sure that a range got an upper bound equal to the
next range with a greater minimum.
2) Removing a continue statement
backport for bug#44059 from mysql-pe to mysql-5.1-bugteam
Using the partition with most rows instead of first partition
to estimate the cardinality of indexes.
is reached
Problem was bad error handling, leaving some new temporary
partitions locked and initialized and some not yet initialized
and locked, leading to a crash when trying to unlock the not
yet initialized and locked partitions
Solution was to unlock the already locked partitions, and not
include any of the new temporary partitions in later unlocks
can lead to bad memory access
Problem: Field_bit is the only field which returns INT_RESULT
and doesn't have unsigned flag. As it's not a descendant of the
Field_num, so using ((Field_num *) field_bit)->unsigned_flag may lead
to unpredictable results.
Fix: check the field type before casting.
From revision r5537 to r5636
r5527 is already applied before
Detailed revision comments:
For HotBackup builds we don't want to hide the symbols.
r5537 | vasil | 2009-07-21 04:31:26 -0500 (Tue, 21 Jul 2009) | 5 lines
branches/zip:
Fixups in ChangeLog: sort filenames alphabetically and wrap to 78 chars per
line.
r5539 | vasil | 2009-07-21 05:28:27 -0500 (Tue, 21 Jul 2009) | 4 lines
branches/zip:
Add a test program to check whether the PAUSE instruction is available.
r5625 | vasil | 2009-08-04 00:52:48 -0500 (Tue, 04 Aug 2009) | 32 lines
branches/zip: Merge 5518:5622 from branches/5.1, resolving conflict in r5622
(after resolving the conflict Makefile.am was not changed so I have made
a dummy change so I can commit and thus record that branches/5.1 has been
merged in branches/zip up to 5622):
------------------------------------------------------------------------
r5622 | vasil | 2009-08-03 15:27:00 +0300 (Mon, 03 Aug 2009) | 20 lines
Changed paths:
M /branches/5.1/Makefile.am
branches/5.1:
Merge a change from MySQL:
------------------------------------------------------------
revno: 2988
committer: Satya B <satya.bn@sun.com>
branch nick: mysql-5.1-bugteam
timestamp: Wed 2009-07-01 11:06:05 +0530
message:
Fix build failure after applying Innodb snapshot 5.1-ss5282
After applying Innodb snapshot 5.1-ss5282, build was broken
because of missing header file.
Adding the header file to Makefile.am after informing the
innodb developers.
modified:
storage/innobase/Makefile.am
------------------------------------------------------------------------
r5626 | vasil | 2009-08-04 00:53:31 -0500 (Tue, 04 Aug 2009) | 4 lines
branches/zip:
Revert the dummy change from c5625.
r5629 | marko | 2009-08-04 06:42:44 -0500 (Tue, 04 Aug 2009) | 1 line
branches/zip: mysql-test: Pass MTR's internal checks.
r5635 | marko | 2009-08-05 06:06:55 -0500 (Wed, 05 Aug 2009) | 2 lines
branches/zip: Replace <number> with NUMBER in some comments,
to avoid problems with Doxygen XML output.
r5636 | marko | 2009-08-05 07:27:30 -0500 (Wed, 05 Aug 2009) | 2 lines
branches/zip: lock_rec_validate_page(): Add the parameter zip_size.
This should help track down Mantis Issue #289.
buffering is used
FORCE INDEX FOR ORDER BY now prevents the optimizer from
using join buffering. As a result the optimizer can use
indexed access on the first table and doesn't need to
sort the complete resultset at the end of the statement.
1. BUG#46000 - using index called GEN_CLUST_INDEX crashes server
Detailed revision comments:
r5895 | jyang | 2009-09-15 03:39:21 +0300 (Tue, 15 Sep 2009) | 5 lines
branches/5.1: Disallow creating index with the name of
"GEN_CLUST_INDEX" which is reserved for the default system
primary index. (Bug #46000) rb://149 approved by Marko Makela.
SELECT ... WHERE ... IN (NULL, ...) does full table scan,
even if the same query without the NULL uses efficient range scan.
The bugfix for the bug 18360 introduced an optimization:
if
1) all right-hand arguments of the IN function are constants
2) result types of all right argument items are compatible
enough to use the same single comparison function to
compare all of them to the left argument,
then
we can convert the right-hand list of constant items to an array
of equally-typed constant values for the further
QUICK index access etc. (see Item_func_in::fix_length_and_dec()).
The Item_null constant item objects have STRING_RESULT
result types, so, as far as Item_func_in::fix_length_and_dec()
is aware of NULLs in the right list, this improvement efficiently
optimizes IN function calls with a mixed right list of NULLs and
string constants. However, the optimization doesn't affect mixed
lists of NULLs and integers, floats etc., because there is no
unique common comparator.
New optimization has been added to ignore the result type
of NULL constants in the static analysis of mixed right-hand lists.
This is safe, because at the execution phase we care about
presence of NULLs anyway.
1. The collect_cmp_types() function has been modified to optionally
ignore NULL constants in the item list.
2. NULL-skipping code of the Item_func_in::fix_length_and_dec()
function has been modified to work not only with in_string
vectors but with in_vectors of other types.
On Mac OS X or Windows, sending a SIGHUP to the server or a
asynchronous flush (triggered by flush_time), would cause the
server to crash.
The problem was that a hook used to detach client API handles
wasn't prepared to handle cases where the thread does not have
a associated session.
The solution is to verify whether the thread has a associated
session before trying to detach a handle.
The 'BEGIN/COMMIT/ROLLBACK' log event could be filtered out if the
database is not selected by --database option of mysqlbinlog command.
This can result in problem if there are some statements in the
transaction are not filtered out.
To fix the problem, mysqlbinlog will output 'BEGIN/ROLLBACK/COMMIT'
in regardless of the database filtering rules.
The 'BEGIN/COMMIT/ROLLBACK' log event could be filtered out if the
database is not selected by --database option of mysqlbinlog command.
This can result in problem if there are some statements in the
transaction are not filtered out.
To fix the problem, mysqlbinlog will output 'BEGIN/ROLLBACK/COMMIT'
in regardless of the database filtering rules.
Backport from 6.0 to 5.1.
Only those sync points are included, which are used in debug_sync.test.
The Debug Sync Facility allows to place synchronization points
in the code:
open_tables(...)
DEBUG_SYNC(thd, "after_open_tables");
lock_tables(...)
When activated, a sync point can
- Send a signal and/or
- Wait for a signal
Nomenclature:
- signal: A value of a global variable that persists
until overwritten by a new signal. The global
variable can also be seen as a "signal post"
or "flag mast". Then the signal is what is
attached to the "signal post" or "flag mast".
- send a signal: Assign the value (the signal) to the global
variable ("set a flag") and broadcast a
global condition to wake those waiting for
a signal.
- wait for a signal: Loop over waiting for the global condition until
the global value matches the wait-for signal.
Please find more information in the top comment in debug_sync.cc
or in the worklog entry.
The problem was that appending values to the end of an existing
ENUM or SET column was being treated as table data modification,
preventing a immediately (fast) table alteration that occurs when
only table metadata is being modified.
The cause was twofold: adding a enumeration or set members to the
end of the list of valid member values was not being considered
a "compatible" table alteration, and for SET columns, the check
was being done upon the max display length and not the underlying
(pack) length of the field.
The solution is to augment the function that checks wether two ENUM
or SET fields are compatible -- by comparing the pack lengths and
performing a limited comparison of the member values.
The bug is not related to MERGE table or TRIGGER. More correct description
would be 'assertion on multi-table UPDATE + NATURAL JOIN + MERGEABLE VIEW'.
On PREPARE stage(see test case) we call mark_common_columns() func which
creates ON condition for NATURAL JOIN and sets appropriate
table read_set bitmaps for fields which are used in ON condition.
On EXECUTE stage mark_common_columns() is not called, we set
necessary read_set bitmaps in setup_conds(). But 'B.f1' field
is already processed and related item alredy fixed before
setup_conds() as updated field and setup_conds can not set
read_set bitmap because of that.
The fix is to set read_set bitmap for appropriate table field even
if Item_direct_view_ref item which represents a refernce to this field
is fixed.
"load data" statements were written to the binlog as a mix of the original statement
and bits recreated from parse-info. This relied on implementation details and broke
with IGNORE_SPACES and versioned comments.
We now completely resynthesize the query for LOAD DATA for binlog (which among other
things normalizes them somewhat with regard to case, spaces, etc.).
We have already parsed the query properly, so we make use of that rather
than mix-and-match string literals and parsed items.
This should make us safe with regard to versioned comments, even those
spanning multiple tokens. Also no longer affected by IGNORE_SPACES.
view definition
During SHOW CREATE VIEW there is no reason to 'anonymize'
errors that name objects that a user does not have access
to. Moreover it was inconsistently implemented. For example
base tables being referenced from a view appear to be ok,
but not views. The manual on the other hand is clear: If a
user has the privileges SELECT and SHOW VIEW, the view
definition is available to that user, period. The fix
changes the behavior to support the manual.
trigger, merge table
The problem with break statements is that they have very
local effects. Hence a break statement within the inner loop
of a nested-loops join caused execution to proceed to the
next table even though a serious error occurred. The problem
was fixed by breaking out the inner loop into its own
method. The change empowers all errors to terminate the
execution.
The errors that will now halt multi-DELETE execution
altogether are
- triggers returning errors
- handler errors
- server being killed
Invalid (old?) table or database name in logs
Problem was still not completely fixed, due to
qouting.
This is the server side only fix (in explain_filename),
the change from filename_to_tablename to use explain_filename
in the InnoDB code must be done before the bug is
fixed.
value from the index (PRIMARY)
With the fix for BUG#46760, we correctly flag the presence of row_type
only when it's actually changed and enables the FAST ALTER TABLE which was
disabled with the BUG#39200.
So the changes made by BUG#46760 makes MySQL data dictionaries to be out of
sync but they are handled already by InnoDB with this BUG#44030.
The test was originally written to handle this but we requested Innodb to
update the test as the data dictionaries were in sync after the fix for
BUG#39200.
Adjusting the innodb-autoinc testcase as mentioned in the comments.
The "socket" variable is not available on Windows even though
the --socket option can be used to specify the pipe name for
local connections that use a named pipe.
The solution is to ensure that the variable is always defined.
checksum)"
The problem was that checksum of GEOMETRY type used memory addresses
in the computation, making it un-repeatable thus useless.
(This patch is a backport from 6.0 branch)
