RPL_SEMI_SYNC_MASTER_CLIENTS=1
Analysis: Uninstalling rpl_semi_sync_slave on slave
will trigger removing the slave logic on Master which
will reduce Rpl_semi_sync_master_clients by one number.
But it happens asynchronously on Master. Having assert
to check this value with zero will have problems on
slow pb2 machines.
Fix: Change assert into wait_for_status_var condition.
GROUP BY
Issue 1:
--------
This problem occurs in the following conditions:
1) A UNION is present in the subquery of select list and
handles multiple columns.
2) Query has a GROUP BY.
A temporary table is created to handle the UNION.
Item_field objects are based on the expressions of the
result of the UNION (ie. the fake_select_lex). While
checking validity of the columns in the GROUP BY list, the
columns of the temporary table are checked in
Item_ident::local_column. But the Item_field objects
created for the temporary table don't have information like
the Name_resolution_context that they belong to or whether
they are dependent on an outer query. Since these members
are null, incorrect behavior is caused.
This can happen when such Item objects are cached to apply
the IN-to-EXISTS transform for Item_row.
Solution to Issue 1:
--------------------
Context information of the first select in the UNION will
be assigned to the new Item_field objects.
Issue 2:
--------
This problem occurs in the following conditions:
1) A UNION is present in the subquery of select list.
2) A column in the UNION's first SELECT refers to a table
in the outer-query making it a dependent union.
3) GROUP BY column refers to the outer-referencing column.
While resolving the select list with an outer-reference, an
Item_outer_ref object is created to handle the
outer-query's GROUP BY list. The Item_outer_ref object
replaces the Item_field object in the item tree.
Item_outer_ref::fix_fields will be called only while fixing
the inner references of the outer query.
Before resolving the outer-query, an Item_type_holder
object needs to be created to handle the UNION. But as
explained above, the Item_outer_ref object has not been
fixed yet. Having a fixed Item object is a pre-condition
for creating an Item_type_holder.
Solution to Issue 2:
--------------------
Use the reference (real_item()) of an Item_outer_ref object
instead of the object itself while creating an
Item_type_holder.
Description: If mysql_stmt_close() encountered error,
it recorded error in prepared statement
but then frees memory assigned to prepared
statement. If mysql_stmt_error() is used
to get error information, it will result
into use after free.
In all cases where mysql_stmt_close() can
fail, error would have been set by
cli_advanced_command in MYSQL structure.
Solution: Don't copy error from MYSQL using set_stmt_errmsg.
There is no automated way to test the fix since
it is in mysql_stmt_close() which does not expect
any reply from server.
Reviewed-By: Georgi Kodinov <georgi.kodinov@oracle.com>
Reviewed-By: Ramil Kalimullin <ramil.kalimullin@oracle.com>
When there are quotes in the USE statement, the mysql client does
not correctly escape them.
The USE statement is processed line by line from the client's parser,
and cannot handle multi-line commands as the server.
The fix is to escape the USE parameters whenever quotes are used.
Problem:-
This crash happens because logged stmt is quite big and while writing
Annotate_rows_log_event it throws EFBIG error but we ignore this error
and do not call cache_data->set_incident().
Solution:-
When we normally write Binlog_log_event we check for error EFBIG, but we did
do this for Annotate_rows_log_event. We check for this error and call
cache_data->set_incident() accordingly.
# Conflicts:
# sql/log.cc
This is another correction of the patch for bug mdev-12670.
If a derived table is merged into a select with STRAIGHT_JOIN
modifier all IN subquery predicates contained in the
specification of the derived table cannot be subject to
conversion to semi-joins.
This patch is a correction of the patch for bug mdev-12670.
With the current code handling semi-joins the following must
be taken into account.
Conversion of an IN subquery predicate into semi-join
has to be blocked if the predicate occurs:
(a) in the ON expression of an outer join
(b) in the ON expression of an inner join embedded directly
or indirectly in the inner nest of an outer join.
The patch for mdev-12670 blocked conversion to semi-joins only
in the case (a), but not in the case (b). This patch blocks
the conversion in both cases.
When an IN subquery predicate was converted to a semi-join that were
materialized and the result of the materialization happened to be
the last in the execution plan then any conjunctive condition with RAND()
turned out to be lost.
Fixed by attaching this condition to the last top base table.
XML
DESCRIPTION
===========
LOAD XML INFILE performance becomes painfully slow if the
tags' value has any space(s) in between them. They're
usually kept intentionally for indentation purpose.
ANALYSIS
========
The extra spaces are calling clear_level() many a times
which is having overhead of clearing taglist etc. This can
be avoided altogether by skipping all such spaces.
FIX
===
Trim all the starting whitespaces from the value before
passing it to read_value()
Backport to 5.5
Current MySQL builds, even on Pushbuild, are not reproducible; they return
different results depending on which directory they are built from (and
Pushbuild uses several different directories). This is because absolute paths
leak into debug information, and even worse, __FILE__. The latter moves code
around enough that we've actually seen sysbench changes on the order of 4% in
some tests.
CMake seemingly insists on using absolute paths, but we can insert our own
layer between CMake and GCC to relativize all paths. Also give the right flags
to get debug information reproducible and turn off build stamping. This makes
the mysqld build 100% bit-for-bit reproducible between runs on my machine,
even when run from different directories.
At some conditions the function opt_sum_query() can apply MIN/MAX
optimizations to to Item_sum objects of a select These optimizations
becomes invalid if this select is the subquery of an IN subquery
predicate that is converted to a EXISTS subquery. Thus in this case
the MIX/MAX optimizations that have been applied in opt_sum_query()
must be rolled back.
This bug appeared in 5.3 when the code for the cost base choice between
materialization and in-to-exists transformation of non-correlated
IN subqueries was introduced. Before this code in-to-exists
transformations were always performed before the call of opt_sum_query().
SYMLINK CHECK RACE CONDITIONS
ANALYSIS:
=========
A potential defect exists in the handling of CREATE
TABLE .. DATA DIRECTORY/ INDEX DIRECTORY which gives way to
the user to gain access to another user table or a system
table.
FIX:
====
The lstat and fstat output of the target files are now
stored which help in determining the identity of the target
files thus preventing the unauthorized access to other
files.
The code that blocked conversion of a IN subselect pedicate to a semi-join
if it occurred in the ON expression of an outer join did not do it correctly.
As a result, the conversion was blocked for IN subselect predicates
encountered in ON expressions of INNER joins or in WHERE conditions
of mergeable views / derived tables. This patch fixes this problem.
This patch corrects the fix for the bug mdev-10693.
It is critical for the function get_best_combination() not to call
create_ref_for_key() for constant tables.
This bug could manifest itself only in multi-table subqueries where
one of the tables is accessed by a constant primary key.
CLIENT (CONTRIBUTION)
DESCRIPTION:
============
Binary data should be printed as hex in the mysql client
when the option binary-as-hex is enabled.
ANALYSIS:
=========
The fix deals only with mysql command line client.
It does not change, at all, the data sent to the
applications. Printing binary data as hex also
allows to use the output in the where clause
of the query.
FIX:
====
A new option 'binary-as-hex' is introduced to print the
binary contents as hex in the mysql client. The option
is disabled by default. When the option is enabled, we
convert the binary data to hex before printing the
contents irrespective of whether it is in tabular,
xml or html format.
/home/travis/build/MariaDB/server/extra/mysqld_safe_helper.c:62:21: warning: too many arguments in call to 'do_usage'
do_usage(argv[0]);
~~~~~~~~ ^
1 warning generated.
Description: If libmysql is compiled with WITH_SSL=NO,
--ssl-* are not useful.
Solution: 1. Restricted WITH_SSL to values : bundled | yes | system
2. Made "bundled" as default value for WITH_SSL. Also,
not specifying WITH_SSL or even specifying WITH_SSL=no
will be treated as/converted to WITH_SSL=bundled.
Reviewed-By: Tor Didriksen <tor.didriksen@oracle.com>
Reviewed-By: Georgi Kodinov <georgi.kodinov@oracle.com>
(cherry picked from commit 3eb2058be34d1a21771fe89ff1a0c08f156899bc)
Description: If libmysql is compiled with WITH_SSL=NO,
--ssl-* are not useful.
Solution: 1. Restricted WITH_SSL to values : bundled | yes | system
2. Made "bundled" as default value for WITH_SSL. Also,
not specifying WITH_SSL or even specifying WITH_SSL=no
will be treated as/converted to WITH_SSL=bundled.
Reviewed-By: Tor Didriksen <tor.didriksen@oracle.com>
Reviewed-By: Georgi Kodinov <georgi.kodinov@oracle.com>
The code that chooses between materialization of a non-correlated
IN subquery and its transformation into an EXISTS correlated
subquery assumes that the execution plan for the outer select
has been already built. However it was not always so if subqueries
occurred in the expressions used for ref access to tables of
the outer select. A call of the function create_ref_for_key() in
get_best_combination() could trigger a premature execution of
the above mentioned code when the execution plan structures for
the outer select were not fully built. This could cause a crash
of the server.
The fix postpones the calls of create_ref_for_key() until the
structures for the execution plan is fully built.
The motivation for this is that Perl is moving towards not having
current directory ./ in @INC by default. This is causing
mysql-test-run.pl to fail in latest Debian Unstable:
https://lists.debian.org/debian-devel-announce/2016/08/msg00013.html
However, we have `use "lib"`, there is no need for current directory
in @INC, except for a gross hack. In mtr_cases.pm, there is a
`require "mtr_misc.pl"`, which hides mtr_misc.pl away in mtr_cases
namespace. And things only work because mysql-test-run.pl loads it
with a different name, `require "lib/mtr_misc.pl"`! (Perl will
`require` only once for each unique filename).
Fix this by only using `require` in main program, and referencing
functions with :: scope from other namespaces. For multi-use in
different namespaces, proper `use` modules should be used.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
FROM THE CURRENT DIRECTORY
DESCRIPTION
===========
When 'mysqlaccess' tool is run, it reads (and executes) the
content of its configuration file 'mysqlaccess.conf' from
the current directory. This is not a recommended behaviour
as someone with ill intentions can insert malicious
instructions into this file which could be executed
whenever this tool is run.
ANALYSIS
========
The configuration file is presently looked for, in the
following folders (in given order):
1. Current directory
2. SYSCONFDIR //This gets expanded
3. /etc/
Owing to the reasons mentioned above, we should not permit
the file to be in the current directory. Since the other
two folders are assumed to be accessible only to authorized
people, the config file is safe to be read from there.
FIX
===
Modified the script so that it looks for the config file
now in the following two folders (in the given order):
1. SYSCONFDIR
2. /etc/
If it's absent from above locations but present in current
directory, an error is thrown asking the user to move the
file to one of the above locations and retry.
NOTE
====
The location paths and their precedence are not documented
for this tool. It needs to be noted as part of the
associated documentation.
