st_select_lex::handle_derived() and mysql_handle_list_of_derived() had
exactly the same implementations.
- Adding a new method LEX::handle_list_of_derived() instead
- Removing public function mysql_handle_list_of_derived()
- Reusing LEX::handle_list_of_derived() in st_select_lex::handle_derived()
The problem was that the introduction of max-thread-mem-used can cause
an allocation error very early, even before mysql_parse() is called.
As mysql_parse() calls thd->reset_for_next_command(), which called
clear_error(), the error number was lost.
Fixed by adding an option to have unique messages for each KILL
signal and change max-thread-mem-used to use this new feature.
This removes a lot of problems with the original approach, where
one could get errors signaled silenty almost any time.
ixed by moving clear_error() from reset_for_next_command() to
do_command(), before any memory allocation for the thread.
Related changes:
- reset_for_next_command() now have an optional parameter if we should
call clear_error() or not. By default it's called, but not anymore from
dispatch_command() which was the original problem.
- Added optional paramater to clear_error() to force calling of
reset_diagnostics_area(). Before clear_error() only called
reset_diagnostics_area() if there was no error, so we normally
called reset_diagnostics_area() twice.
- This change removed several duplicated calls to clear_error()
when starting a query.
- Reset max_mem_used on COM_QUIT, to protect against kill during
quit.
- Use fatal_error() instead of setting is_fatal_error (cleanup)
- Set fatal_error if max_thead_mem_used is signaled.
(Same logic we use for other places where we are out of resources)
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()
Issue:
------
While using the LOAD statement to insert data into an
updateable view, the check to verify whether a column
is actually updatable is missing.
Solution for 5.5 and 5.6:
-------------------------
For a view whose column-list in specified in the LOAD
command, this check is not performed. This fix adds the
check.
This is a partial backport of Bug#21097485.
Solution for 5.7 and trunk:
---------------------------
For a view whose column-list is specified in the LOAD
command, this check is already performed. This fix adds the
same check when no column-list is specified.
Partially backporting MDEV-9874 from 10.2 to 10.0
READ_INFO::read_field() raised the ER_INVALID_CHARACTER_STRING error
when reading an escape character followed by a multi-byte character.
Raising wellformedness errors in READ_INFO::read_field() was wrong,
because the main goal of READ_INFO::read_field() is to *unescape* the
data which was presumably escaped using mysql_real_escape_string(),
using the same character set with the one specified in
"LOAD DATA INFILE ... CHARACTER SET ..." (or assumed by default).
During LOAD DATA, multi-byte characters are not always scanned as a single
entity! In case of escaped data, parts of a multi-byte character can be
scanned on different loop iterations. So the old code erroneously tested
welformedness in the middle of a multi-byte character.
Moreover, the data after unescaping can go into a BLOB field, not a text field.
Wellformedness tests are meaningless in this case.
Ater this patch, wellformedness is only checked later, during
Field::store(str,length,cs) time. The loop that scans bytes only
makes sure to revert the changes made by mysql_real_escape_string().
Note, in some cases users can supply data which did not really go through
mysql_real_escape_string() and was escaped by some other means,
or was not escaped at all. The file reported in this MDEV contains
the string "\ä", which is an example of such improperly escaped data, as
- either there should be two backslashes: "\\ä"
- or there should be no backslashes at all: "ä"
mysql_real_escape_string() could not generate "\ä".
The crash happened when if my_error() was called for any reasons during loading
(e.g. a bad multi-byte sequence or a bad GEOMETRY value was found).
The server sent both error and progress packets, so the client disconnected.
The server then crashed on a assert about a wrong packet order in Debug build.
The server also tried to read from a closed socket when calling
READ_INFO::skip_data_till_eof().
As the crash happened only with "mysql" running in interactive mode,
no tests are possible. The problem was not reproducible with
"mysqltest" or "mysql" in batch mode.
LOAD DATA AT MASTER.
Revert "BUG#23080148 - BACKPORT BUG 14653594 AND BUG 20683959 TO"
This reverts commit 1d31f5b3090d129382b50b95512f2f79305715a1.
The commit causes replication incompatibility between minor revisions
and based on discussion with Srinivasarao, the patch is reverted.
MYSQL-5.5
The bug asks for a backport of bug#1463594 and bug#20682959. This
is required because of the fact that if replication is enabled, master
transaction can commit whereas slave can't commit due to not exact
'enviroment'. This manifestation is seen in bug#22024200.
'SYSTEM LOCK' IN PROCESSLIST
Analysis
=========
Show processlist shows 'System Lock' in 'State' field while
LOAD DATA INFILE is running.
thd->proc_info update is missing in LOAD DATA INFILE path.
Thus any request will get last unpdated status from lock_table()
during open_table().
Fix:
=======
Update state information from LOAD DATA INFILE path.
NOT NULL constraint must be checked *after* the BEFORE triggers.
That is for INSERT and UPDATE statements even NOT NULL fields
must be able to store a NULL temporarily at least while
BEFORE INSERT/UPDATE triggers are running.
* move common code to a new set_bad_null_error() function
* move repeated comparison out of the loop
* remove unused code
* unused method Table_triggers_list::set_table
* redundant condition (if (table) after table was dereferenced)
* add an assert
- Part 3: Adding mem_root to push_back() and push_front()
Other things:
- Added THD as an argument to some partition functions.
- Added memory overflow checking for XML tag's in read_xml()
DESCRIPTION
===========
Inability of mysql LOAD XML command to handle empty XML
tags i.e. <row><tag/></row>. Also the behaviour is wrong
and (different than above) when there is a space in empty
tag i.e. <row><tag /></row>
ANALYSIS
========
In read_xml() the case where we encounter a close tag ('/')
we're decreasing the 'level' blindly which is wrong.
Actually when its an without-space-empty-tag (succeeding
char is '>'), we need to skip the decrement. In other words
whenever we hit a close tag ('/'), decrease the 'level'
only when (i) It's not an (without space) empty tag i.e.
<tag/> or, (ii) It is of format <row col="val" .../>
FIX
===
The switch case for '/' is modified. We've removed the
blind decrement of 'level'. We do it only when its not an
without-space-empty-tag. Also we are setting 'in_tag' to
false to let program know that we're done reading current
tag (required in the case of format <row col="val" .../>)
- Changed ER(ER_...) to ER_THD(thd, ER_...) when thd was known or if there was many calls to current_thd in the same function.
- Changed ER(ER_..) to ER_THD_OR_DEFAULT(current_thd, ER...) in some places where current_thd is not necessary defined.
- Removing calls to current_thd when we have access to thd
Part of this is optimization (not calling current_thd when not needed),
but part is bug fixing for error condition when current_thd is not defined
(For example on startup and end of mysqld)
Notable renames done as otherwise a lot of functions would have to be changed:
- In JOIN structure renamed:
examined_rows -> join_examined_rows
record_count -> join_record_count
- In Field, renamed new_field() to make_new_field()
Other things:
- Added DBUG_ASSERT(thd == tmp_thd) in Item_singlerow_subselect() just to be safe.
- Removed old 'tab' prefix in JOIN_TAB::save_explain_data() and use members directly
- Added 'thd' as argument to a few functions to avoid calling current_thd.
* remove unused (and not implemented) WRITE_NET type
* remove cast in my_b_write() macro. my_b_* macros are
function-like, casts are responsibility of the caller
* replace hackish _my_b_write(info,0,0) with the explicit
my_b_flush_io_cache() in my_b_write_byte()
* remove unused my_b_fill_cache()
* replace pbool -> my_bool
* make internal IO_CACHE functions static
* reformat comments, correct typos, remove obsolete comments (ISAM)
* assert valid cache type in init_functions()
* use IO_ROUND_DN() macro where appropriate
* remove unused DBUG_EXECUTE_IF in _my_b_cache_write()
* remove unnecessary __attribute__((unused))
* fix goto error in parse_file.cc
* remove redundant reinit_io_cache() in uniques.cc
* don't do reinit_io_cache() if the cache was not initialized
in ma_check.c
* extract duplicate functionality from various _my_b_*_read
functions into a common wrapper. Same for _my_b_*_write
* create _my_b_cache_write_r instead of having if's in
_my_b_cache_write (similar to existing _my_b_cache_read and
_my_b_cache_read_r)
* don't call mysql_file_write() from my_b_flush_io_cache(),
call info->write_function() instead
remove some 14-year old code that added support for
LOAD DATA replication to IO_CACHE:
* three callbacks, of which only two were actually used and that
were only needed for LOAD DATA replication but were
tested in every IO_CACHE instance
* an additional opaque void * argument in IO_CACHE, also only
used for LOAD DATA replication, but present everywhere
* the code to close IO_CACHE prematurely in LOAD DATA to have
these callbacks called in the correct order and a long
comment explaining what will happen if IO_CACHE is not
closed prematurely
* a variable to track whether IO_CACHE was closed prematurely
(to avoid double-closing it)
