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.
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.
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" .../>)
A "field" could be either an Item_field or
(if loading into a view) an Item_direct_ref that references Item_field.
Also: when iterating fields, use fields of the TABLE_LIST (table or view),
not fields of a TABLE (actual underlying table - might have more columns).
Bug#18396916 MAIN.OUTFILE_LOADDATA TEST FAILS ON ARM, AARCH64, PPC/PPC64
The recorded results for the failing tests were wrong.
They were introduced by the patch for
Bug#30946 mysqldump silently ignores --default-character-set when used with --tab
Correct results were returned for platforms where 'char' is implemented as unsigned.
This was reported as
Bug#46895 Test "outfile_loaddata" fails (reproducible)
Bug#11755168 46895: TEST "OUTFILE_LOADDATA" FAILS (REPRODUCIBLE)
The patch for that bug fixed only parts of the problem,
leaving the incorrect results in the .result file.
Solution: use 'uchar' for field_terminator and line_terminator on all platforms.
Also: remove some un-necessary casts, leaving the ones we actually need.
Bug#18396916 MAIN.OUTFILE_LOADDATA TEST FAILS ON ARM, AARCH64, PPC/PPC64
The recorded results for the failing tests were wrong.
They were introduced by the patch for
Bug#30946 mysqldump silently ignores --default-character-set when used with --tab
Correct results were returned for platforms where 'char' is implemented as unsigned.
This was reported as
Bug#46895 Test "outfile_loaddata" fails (reproducible)
Bug#11755168 46895: TEST "OUTFILE_LOADDATA" FAILS (REPRODUCIBLE)
The patch for that bug fixed only parts of the problem,
leaving the incorrect results in the .result file.
Solution: use 'uchar' for field_terminator and line_terminator on all platforms.
Also: remove some un-necessary casts, leaving the ones we actually need.
LOCAL AND IMPORT ERRORS
Description:
-----------
This bug happens due to the fact that current algorithm is designed
that in the case of LOCAL load of data, in case of the error, the
remaining part of the file is read in order to return the proper
error message to the client side.
But, the problem with current implementation is that data stream
for the client side is cleared only in the case where line delimiters
exist, which is not a case with, for example fixed width
fields.
Fix:
----
Ported patch provided by Sinisa Milivojevic n bug report for this
issue to 5.5+ versions.
As part of this patch code is changed to clear the data stream
by calling new member function "READ_INFO::skip_data_till_eof".
LOCAL AND IMPORT ERRORS
Description:
-----------
This bug happens due to the fact that current algorithm is designed
that in the case of LOCAL load of data, in case of the error, the
remaining part of the file is read in order to return the proper
error message to the client side.
But, the problem with current implementation is that data stream
for the client side is cleared only in the case where line delimiters
exist, which is not a case with, for example fixed width
fields.
Fix:
----
Ported patch provided by Sinisa Milivojevic n bug report for this
issue to 5.5+ versions.
As part of this patch code is changed to clear the data stream
by calling new member function "READ_INFO::skip_data_till_eof".
REPEATED TWICE IN BINLOG
Problem:
=======
If LOAD DATA ... SET ... is used the last argument of SET is
repeated twice in replication binlog.
Analysis:
========
LOAD DATA statements are reconstructed once again before
they are written to the binary log. When SET clauses are
specified as part of LOAD DATA statement, these SET clause
user command strings need to be stored in order to rebuild
the original user command. During parsing each column and
the value in the SET command are stored in two differenet
lists. All the values are stored in a string list.
When SET expression has more than one value as shown in the
following example:
SET a = @a, b = CONCAT(@b, '| 123456789');
Parser extracts values in the following manner i.e Item name
, value string, actual length of the value of the item with
in the string.
Item a:
Value for a:"= @a, b = CONCAT(@b, '| 123456789')
str_length = 4
Item b:
Value for b:"= CONCAT(@b, '| 123456789')
str_length = 27
During reconstructing the LOAD DATA command the above
strings are retrived as it is and appended to the LOAD DATA
statement. Hence it becomes as shown below.
SET `a`= @a, b = CONCAT(@b, '| 123456789'),
`b`= CONCAT(@b, '| 123456789')
Fix:
===
During reconstruction of SET command, retrieve exact item
value string rather than reading the entire string.
sql/sql_load.cc:
Added code to extract the exact Item value.
REPEATED TWICE IN BINLOG
Problem:
=======
If LOAD DATA ... SET ... is used the last argument of SET is
repeated twice in replication binlog.
Analysis:
========
LOAD DATA statements are reconstructed once again before
they are written to the binary log. When SET clauses are
specified as part of LOAD DATA statement, these SET clause
user command strings need to be stored in order to rebuild
the original user command. During parsing each column and
the value in the SET command are stored in two differenet
lists. All the values are stored in a string list.
When SET expression has more than one value as shown in the
following example:
SET a = @a, b = CONCAT(@b, '| 123456789');
Parser extracts values in the following manner i.e Item name
, value string, actual length of the value of the item with
in the string.
Item a:
Value for a:"= @a, b = CONCAT(@b, '| 123456789')
str_length = 4
Item b:
Value for b:"= CONCAT(@b, '| 123456789')
str_length = 27
During reconstructing the LOAD DATA command the above
strings are retrived as it is and appended to the LOAD DATA
statement. Hence it becomes as shown below.
SET `a`= @a, b = CONCAT(@b, '| 123456789'),
`b`= CONCAT(@b, '| 123456789')
Fix:
===
During reconstruction of SET command, retrieve exact item
value string rather than reading the entire string.
LOAD DATA CAN CAUSE SQL INJECTION
Problem:
=======
A long SET expression in LOAD DATA is incorrectly truncated
when written to the binary log.
Analysis:
========
LOAD DATA statements are reconstructed once again before
they are written to the binary log. When SET clauses are
specified as part of LOAD DATA statement, these SET clause
user command strings need to be stored as it is inorder to
reconstruct the original user command. At present these
strings are stored as part of SET clause item tree's
top most Item node's name itself which is incorrect. As an
Item::name can be of MAX_ALIAS_NAME (256) size. Hence the
name will get truncated to "255".
Because of this the rewritten LOAD DATA statement will be
terminated incorrectly. When this statment is read back by
the mysqlbinlog tool it reads a starting single quote and
continuos to read till it finds an ending quote. Hence any
statement written post ending quote will be considered as
a new statement.
Fix:
===
As name field has length restriction the string value
should not be stored in Item::name. A new String list is
maintained to store the SET expression values and this list
is read during reconstrution.
sql/sql_lex.cc:
Clear the load data set string list during each query
execution.
sql/sql_lex.h:
Added a new String list to store the load data operation's
SET clause user command strings.
sql/sql_load.cc:
Read the SET clause user command strings from load data
set string list.
sql/sql_yacc.yy:
Store the SET caluse user command string as part of load
data set string list.
LOAD DATA CAN CAUSE SQL INJECTION
Problem:
=======
A long SET expression in LOAD DATA is incorrectly truncated
when written to the binary log.
Analysis:
========
LOAD DATA statements are reconstructed once again before
they are written to the binary log. When SET clauses are
specified as part of LOAD DATA statement, these SET clause
user command strings need to be stored as it is inorder to
reconstruct the original user command. At present these
strings are stored as part of SET clause item tree's
top most Item node's name itself which is incorrect. As an
Item::name can be of MAX_ALIAS_NAME (256) size. Hence the
name will get truncated to "255".
Because of this the rewritten LOAD DATA statement will be
terminated incorrectly. When this statment is read back by
the mysqlbinlog tool it reads a starting single quote and
continuos to read till it finds an ending quote. Hence any
statement written post ending quote will be considered as
a new statement.
Fix:
===
As name field has length restriction the string value
should not be stored in Item::name. A new String list is
maintained to store the SET expression values and this list
is read during reconstrution.
QUOTING IN REPLICATION
Problem: Misquoting or unquoted identifiers may lead to
incorrect statements to be logged to the binary log.
Fix: we use specialized functions to append quoted identifiers in
the statements generated by the server.
QUOTING IN REPLICATION
Problem: Misquoting or unquoted identifiers may lead to
incorrect statements to be logged to the binary log.
Fix: we use specialized functions to append quoted identifiers in
the statements generated by the server.
dbug/tests.c:
Added __attribute__((unused)) to get rid of compiler warning
server-tools/instance-manager/guardian.cc:
Added __attribute__((unused)) to get rid of compiler warning
sql/filesort.cc:
Added __attribute__((unused)) to get rid of compiler warning
sql/slave.cc:
Added __attribute__((unused)) to get rid of compiler warning
sql/sql_load.cc:
Added __attribute__((unused)) to get rid of compiler warning
sql/sql_table.cc:
Added __attribute__((unused)) to get rid of compiler warning
storage/maria/ma_blockrec.c:
Added __attribute__((unused)) to get rid of compiler warning
storage/maria/ma_check.c:
Added missing cast
storage/maria/ma_loghandler.c:
Added __attribute__((unused)) to get rid of compiler warning
storage/maria/ma_recovery.c:
Added __attribute__((unused)) to get rid of compiler warning
storage/pbxt/src/cache_xt.cc:
Added __attribute__((unused)) to get rid of compiler warning
storage/xtradb/fil/fil0fil.c:
Removed not used variable
storage/xtradb/handler/ha_innodb.cc:
Use unused variable
vio/viosocket.c:
Remove usage of not used variable
vio/viosslfactories.c:
Added cast
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
- If USER is given, all threads for that user is signaled
- If SOFT is used then the KILL will not be sent to the handler. This can be used to not interrupt critical things in the handler like 'REPAIR'.
Internally added more kill signals. This gives us more information of why a query/connection was killed.
- KILL_SERVER is used when server is going down. In this case the users gets ER_SHUTDOWN as the reason connection was killed.
- Changed signals to number in correct order, which makes it easier to test how the signal should affect the code.
- New error message ER_CONNECTION_KILLED if connection was killed by 'KILL CONNECTION'. Before we got error ER_SHUTDOWN.
Changed names of not used parameters KILL_QUERY & KILL_CONNCTION to mysql_kill() to not conflict with defines in the server
include/mysql.h.pp:
Updated file
include/mysql_com.h:
Changed names of not used parameters KILL_QUERY & KILL_CONNCTION to mysql_kill() to not conflict with defines in the server
mysql-test/r/kill.result:
Added test of KILL USER
mysql-test/suite/rpl/r/rpl_stm_000001.result:
Updated error code
mysql-test/suite/rpl/t/rpl_stm_000001.test:
Updated error codes
mysql-test/t/flush_read_lock_kill.test:
Updated error codes
mysql-test/t/kill.test:
Added test of KILL USER
plugin/handler_socket/handlersocket/database.cpp:
Removed THD:: from KILL
sql/debug_sync.cc:
Removed THD:: from KILL
sql/event_scheduler.cc:
Removed THD:: from KILL
sql/filesort.cc:
Removed THD:: from KILL
sql/ha_ndbcluster_binlog.cc:
Removed THD:: from KILL
sql/handler.cc:
Removed THD:: from KILL
Simplify code.
sql/lex.h:
Added new keywords HARD | SOFT
sql/log.cc:
Removed THD:: from KILL
Added testing of new error ER_CONNECTION_KILLED
sql/log_event.cc:
Removed THD:: from KILL
Added testing of new error ER_CONNECTION_KILLED
sql/mysql_priv.h:
Added new prototypes
sql/mysqld.cc:
Removed THD:: from KILL
Use KILL_SERVER_HARD signal on shutdown.
sql/scheduler.cc:
Removed THD:: from KILL
Simplify test if connection should be killed
sql/share/errmsg.txt:
New error message ER_CONNECTION_KILLED
sql/slave.cc:
Removed THD:: from KILL
sql/sp_head.cc:
Removed THD:: from KILL
sql/sql_base.cc:
Removed THD:: from KILL
sql/sql_cache.cc:
Removed THD:: from KILL
sql/sql_class.cc:
Removed THD:: from KILL
Added killed_errno()
Only signal kill to storage engine if HARD bit is set.
sql/sql_class.h:
Move KILL options out from THD to make them easier to use in sql_yacc.yy
sql/sql_connect.cc:
Removed THD:: from KILL
sql/sql_delete.cc:
Removed THD:: from KILL
sql/sql_error.cc:
Removed THD:: from KILL
sql/sql_insert.cc:
Removed THD:: from KILL
Simplifed testing if thread is killed.
sql/sql_lex.h:
Added kill options to st_lex
sql/sql_load.cc:
Removed THD:: from KILL
sql/sql_parse.cc:
Added kill options to st_lex
Simplifed and optimzed testing of thd->killed at end of query
Added support for KILL USER
Extended sql_kill() to allow use of more kill signals.
sql/sql_repl.cc:
Removed THD:: from KILL
sql/sql_show.cc:
Removed THD:: from KILL
Simplied testing if query/connection was killed
sql/sql_table.cc:
Removed THD:: from KILL
sql/sql_update.cc:
Removed THD:: from KILL
sql/sql_yacc.yy:
Added support for new KILL syntax: KILL [HARD|SOFT] [CONNECTION|QUERY] [ID | USER user_name]
storage/archive/ha_archive.cc:
Simplify compilation
storage/maria/ha_maria.cc:
Removed THD:: from KILL
GCC 4.6 has new -Wunused-but-set-variable flag, which is enabled
by -Wall, that causes GCC to emit a warning whenever a local variable
is assigned to, but otherwise unused (aside from its declaration).
Since the maintainer mode uses -Wall and -Werror, source code which
triggers these warnings will be rejected. That is, these warnings
become hard errors.
The solution is to fix the code which triggers these specific warnings.
In most of the cases, this is a welcome cleanup as code which triggers
this warning is probably dead anyway.
dbug/dbug.c:
Unused but set.
libmysqld/lib_sql.cc:
Length is not necessary as the converted error message is always
null-terminated.
sql/item_func.cc:
Make get_var_with_binlog private to this compilation unit.
If a error was raised, do not attempt to evaluate the user
variable as the statement execution will be interrupted
anyway.
sql/mysqld.cc:
Use a void expression to silence the warning. Avoids the use of
macros that would make the code more unreadable than it already is.
sql/protocol.cc:
Length is not necessary as the converted error message is always
null-terminated. Remove unnecessary casts and assignment.
sql/sql_class.h:
Function is only used in a single compilation unit.
sql/sql_load.cc:
Only use the variable outside of EMBEDDED_LIBRARY.
storage/innobase/btr/btr0cur.c:
Do not retrieve field, only the record length is being used.
storage/perfschema/pfs.cc:
Use a void expression to silence the warning.
tests/mysql_client_test.c:
Unused but set.
unittest/mysys/lf-t.c:
Unused but set.
GCC 4.6 has new -Wunused-but-set-variable flag, which is enabled
by -Wall, that causes GCC to emit a warning whenever a local variable
is assigned to, but otherwise unused (aside from its declaration).
Since the maintainer mode uses -Wall and -Werror, source code which
triggers these warnings will be rejected. That is, these warnings
become hard errors.
The solution is to fix the code which triggers these specific warnings.
In most of the cases, this is a welcome cleanup as code which triggers
this warning is probably dead anyway.
