*with --with-charset=utf8*
Problem: wrong LONG TEXT field length is sent to a client
when multibyte server character set used.
Fix: always limit field length sent to a client to 2^32,
as we store it in 4 byte slot.
Note: mysql_client_test changed accordingly.
Problem: storing "SELECT ... INTO @var ..." results in variables we used val_xxx()
methods which returned results of the current row.
So, in some cases (e.g. SELECT DISTINCT, GROUP BY or HAVING) we got data
from the first row of a new group (where we evaluate a clause) instead of
data from the last row of the previous group.
Fix: use val_xxx_result() counterparts to get proper results.
for bug #15936.
On some platforms fenv.h may #undef the min/max macros
defined in my_global.h.
Fixed by moving the #include directive for fenv.h from
mysqld.cc to my_global.h before definitions for min/max.
Bug#41112: crash in mysql_ha_close_table/get_lock_data with alter table
The problem is that the server wasn't handling robustly failures
to re-open a table during a HANDLER .. READ statement. If the
table needed to be re-opened due to it's storage engine being
altered to one that doesn't support HANDLER, a reference (dangling
pointer) to a closed table could be left in place and accessed in
later attempts to fetch from the table using the handler. Also,
if the server failed to set a error message if the re-open
failed. These problems could lead to server crashes or hangs.
The solution is to remove any references to a closed table and
to set a error if reopening a table during a HANDLER .. READ
statement fails.
There is no test case in this change set as the test depends on
a testing feature only available on 5.1 and later.
Both of our own implementations of rint(3) were inconsistent with the
most common behavior of rint() on those platforms that have it: round
to nearest, break ties by rounding to nearest even.
Fixed by leaving just one implementation of rint() in our source tree,
and changing its behavior to match the most common native
implementations on other platforms.
Signed integer format specifier forced to print the binlog header with server_id
negative if the unsigned value sets the sign-bit ON.
Fixed with correcting the specifier to correspond to typeof(server_id) == ulong.
connections
The problem is that tables can enter open table cache for a thread without
being properly cleaned up. This can happen if make_join_statistics() fails
to read a const table because of e.g. a deadlock. It does set a member of
TABLE structure to a value it allocates, but doesn't clean-up this setting
on error nor does it set the rest of the members in JOIN to allow for
automatic cleanup.
As a result when such an error occurs and the next statement depends re-uses
the table from the open tables cache it will get it with this
TABLE::reginfo.join_tab pointing to a memory area that's freed.
Fixed by making sure make_join_statistics() cleans up TABLE::reginfo.join_tab
on error.
In case of ROW item each compared pair does not
check if argumet collations can be aggregated and
thus appropiriate item conversion does not happen.
The fix is to add the check and convertion for ROW
pairs.
returns short string value.
Multibyte character sets were not taken into account when
calculating max_length in Item_param::convert_str_value(). As a
result, string parameters of a prepared statement could be
truncated later when calculating string length in characters by
dividing length in bytes by the charset's mbmaxlen value (e.g. in
Field_varstring::store()).
Fixed by taking charset's mbmaxlen into account when calculating
max_length in Item_param::convert_str_value().
Additional fix:
1. Revert the unification of DROP FUNCTION
and DROP PROCEDURE, because DROP FUNCTION can be used to
drop UDFs (that have a non-qualified name and don't require
database name to be present and valid).
2. Fixed the case sensitivity problem by adding a call to
check_db_name() (similar to the sp_name production).
MATCH() function accepts column list as an argument. It was possible to override
this requirement with aliased non-column select expression. Which results in
server crash.
With this fix aliased non-column select expressions are not accepted by MATCH()
function, returning an error.
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
date_format functions
String::realloc() did not check whether the existing string data fits in
the newly allocated buffer for cases when reallocating a String object
with external buffer (i.e.alloced == FALSE). This could lead to memory
overruns in some cases.
The parser was not using the correct fully-qualified-name
production for DROP FUNCTION.
Fixed by copying the production from DROP PROCEDURE.
Tested in the windows specific suite to make sure it's
tested on a case-insensitive file system.
In 37553 we declared longlong results for
class Item_str_timefunc as per comments/docs,
but didn't add a method for that. And the
default just wasn't good enough for some
cases.
Changeset adds dedicated val_int() to class.
ORDER BY could cause a server crash
Dependent subqueries like
SELECT COUNT(*) FROM t1, t2 WHERE t2.b
IN (SELECT DISTINCT t2.b FROM t2 WHERE t2.b = t1.a)
caused a memory leak proportional to the
number of outer rows.
The make_simple_join() function has been modified to
JOIN class method to store join_tab_reexec and
table_reexec values in the parent join only
(make_simple_join of tmp_join may access these values
via 'this' pointer of the parent JOIN).
NOTE: this patch doesn't include standard test case (this is
"out of memory" bug). See bug #42037 page for test cases.
Problem: some queries using NAME_CONST(.. COLLATE ...)
lead to server crash due to failed type cast.
Fix: return the underlying item's type in case of
NAME_CONST(.. COLLATE ...) to avoid wrong casting.
functions
String::realloc() did not check whether the existing string data fits in the newly
allocated buffer for cases when reallocating a String object with external buffer
(i.e.alloced == FALSE). This could lead to memory overruns in some cases.
When storing a NULL to a TIMESTAMP NOT NULL DEFAULT ...,
NULL returned from some functions threw a 'cannot be NULL error.'
NULL-returns now correctly result in the timestamp-field being
assigned its default value.
If the system time is adjusted back during a query execution
(resulting in the end time being earlier than the start time)
the code that prints to the slow query log gets confused and
prints unsigned negative numbers.
Fixed by not logging the statements that would have negative
execution time due to time shifts.
No test case since this would involve changing the system time.
messed up
"ROW(...) IN (SELECT ... FROM DUAL)" always returned TRUE.
Item_in_subselect::row_value_transformer rewrites "ROW(...)
IN SELECT" conditions into the "EXISTS (SELECT ... HAVING ...)"
form.
For a subquery from the DUAL pseudotable resulting HAVING
condition is an expression on constant values, so further
transformation with optimize_cond() eliminates this HAVING
condition and resets JOIN::having to NULL.
Then JOIN::exec treated that NULL as an always-true-HAVING
and that caused a bug.
To distinguish an optimized out "HAVING TRUE" clause from
"HAVING FALSE" we already have the JOIN::having_value flag.
However, JOIN::exec() ignored JOIN::having_value as described
above as if it always set to COND_TRUE.
The JOIN::exec method has been modified to take into account
the value of the JOIN::having_value field.
Various parts of code used different 'precision' arguments for sprintf("%g") when converting
floating point numbers to a string. This led to differences in results in some cases
depending on whether the text-based or prepared statements protocol is used for a query.
Fixed by changing arguments to sprintf("%g") to always be 15 (DBL_DIG) so that results are
consistent regardless of the protocol.
This patch will be null-merged to 6.0 as the problem does not exists there (fixed by the
patch for WL#2934).
The problem is that the query cache was storing partial results
if the statement failed when sending the results to the client.
This could cause clients to hang when trying to read the results
from the cache as they would, for example, wait indefinitely for
a eof packet that wasn't saved.
The solution is to always discard the caching of a query that
failed to send its results to the associated client.
Views weren't sync()d the same way other structures were.
In creating the FRM for views, obey the same rules for variable
"sync_frm" as for everything else.
The problem is that the query cache stores packets containing
the server status of the time when the cached statement was run.
This might lead to a wrong transaction status in the client side
if a statement is cached during a transaction and is later served
outside a transaction context (and vice-versa).
The solution is to take into account the transaction status when
storing in and serving from the query cache.
The greedy optimizer tracks the current level of nested joins and the position
inside these by setting and maintaining a state that's global for the whole FROM
clause.
This state was correctly maintained inside the selection of the next partial plan
table (in best_extension_by_limited_search()).
greedy_search() also moves the current position by adding the last partial match
table when there's not enough tables in the partial plan found by
best_extension_by_limited_search().
This may require update of the global state variables that describe the current
position in the plan if the last table placed by greedy_search is not a top-level
join table.
Fixed by updating the state after placing the partial plan table in greedy_search()
in the same way this is done on entering the best_extension_by_limited_search().
Fixed the signature of the function called to update the state :
check_interleaving_with_nj
When substituting system constant functions with a constant result
the server was not expecting that the function may return NULL.
Fixed by checking for NULL and returning Item_null (in the relevant
collation) if the result of the system constant function was NULL.
Added global status variable 'Queries' which represents
total amount of queries executed by server including
statements executed by SPs.
note: It's old behaviour of 'Questions' variable.
Table could be marked dependent because it is
either 1) an inner table of an outer join, or 2) it is a part of
STRAIGHT_JOIN. In case of STRAIGHT_JOIN table->maybe_null should not
be assigned. The fix is to set st_table::maybe_null to 'true' only
for those tables which are used in outer join.
The problem is that we cannot insert new record into memory table
when table size exceeds max memory table size.
The fix is to use schema_table_store_record() function which
converts memory table into MyISAM in case of table size exceeding.
Note:
There is no test case for this bug, the reason is that
1. The code that was added already is checked(i.e. works) with existing tests
2. Correct work of schema_table_store_record() is checked with other test cases
(information_schema tests)
So new code is fully covered with existing test cases.
The MONTHNAME/DAYNAME functions
returns binary string, so the LOWER/UPPER functions
are not effective on the result of MONTHNAME/DAYNAME call.
Character set of the MONTHNAME/DAYNAME function
result has been changed to connection character set.
- QUICK_INDEX_MERGE_SELECT deinitializes its rnd_pos() scan when it reaches EOF, but we
need to make the deinitialization in QUICK_INDEX_MERGE_SELECT destructor also. This is because
certain execution strategies can stop scanning without reaching EOF, then then try to do a full
table scan on this table. Failure to deinitialize caused the full scan to use (already empty)
table->sort and produce zero records.
branches/5.0 bug#39483 InnoDB hang on adaptive hash because of out
of order ::open() call by MySQL
Under some conditions MySQL calls ::open with search_latch leading
to a deadlock as we try to acquire dict_sys->mutex inside ::open
breaking the latching order. The fix is to release search_latch.
Reviewed by: Heikki
IF(..., CAST(longtext AS UNSIGNED), signed_val)
(was: LEFT JOIN on inline view crashes server)
Select from a LONGTEXT column wrapped with an expression
like "IF(..., CAST(longtext_column AS UNSIGNED), smth_signed)"
failed an assertion or crashed the server. IFNULL function was
affected too.
LONGTEXT column item has a maximum length of 32^2-1 bytes,
at the same time this is a maximum possible length of any
MySQL item. CAST(longtext_column AS UNSIGNED) returns some
unsigned numeric result of length 32^2-1, so the result of
IF/IFNULL function of this number and some other signed number
will have text length of (32^2-1)+1=32^2 (one byte for the
minus sign) - there is integer overflow, and the length is
equal to zero. That caused assert/crash.
CAST AS UNSIGNED function has been modified to limit maximal
length of resulting number to 67 (maximal length of DECIMAL
and two characters for minus sign and dot).
IF(..., CAST(longtext AS UNSIGNED), signed_val)
(was: LEFT JOIN on inline view crashes server)
Select from a LONGTEXT column wrapped with an expression
like "IF(..., CAST(longtext_column AS UNSIGNED), smth_signed)"
failed an assertion or crashed the server. IFNULL function was
affected too.
LONGTEXT column item has a maximum length of 32^2-1 bytes,
at the same time this is a maximum possible length of any
MySQL item. CAST(longtext_column AS UNSIGNED) returns some
unsigned numeric result of length 32^2-1, so the result of
IF/IFNULL function of this number and some other signed number
will have text length of (32^2-1)+1=32^2 (one byte for the
minus sign) - there is integer overflow, and the length is
equal to zero. That caused assert/crash.
The bug has been fixed by the same solution as in the CASE
function implementation.
Bug#37671 crash on prepared statement + cursor + geometry + too many open files!
if mysql_execute_command() returns error then free materialized_cursor object.
is_rnd_inited is added to satisfy rnd_end() assertion
(handler may be uninitialized in some cases)
BUG#39325 Server crash inside MYSQL_LOG::purge_first_log halts replicaiton
The patch reverses the order of the purging and updating events for log and relay-log.info/index files respectively.
This solves the problem of having holes caused by crashes happening between updating info/index files and purging logs.
NOTE: This is a combined patch for BUG#38826 and BUG#39325. This patch is based on bugteam tree and takes into account reviewers suggestions.
Updated MySQL time handling code to react correctly on UTC leap second additions.
MySQL functions that return the OS current time, like e.g. CURDATE(), NOW() etc
will return :59:59 instead of :59:60 or 59:61.
As a result the reader will receive :59:59 for 2 or 3 consecutive seconds
during the leap second.
This fix will not affect the values returned by UNIX_TIMESTAMP() for leap seconds.
But note that when converting the value returned by UNIX_TIMESTAMP() to broken
down time the correction of leap seconds will still be applied.
Note that this fix will make a difference *only* if the OS is specially configured
to return leap seconds from the OS time calls or when using a MySQL time zone
defintion that has leap seconds.
Even after this change date/time literals (or other broken down time
representations) with leap seconds (ending on :59:60 or 59:61) will still be
considered illegal and discarded by the server with an error or
a warning depending on the sql mode.
Added a test case to demonstrate the effect of the fix.
TABLE_LIST doesn't free Strings in its string lists
(TABLE_LIST::use_index and TABLE_liST::ignore_index), so
calling c_ptr_safe() on that Strings leads to memleaks.
OTOH "safe" c_ptr_safe() is not necessary there and we can
replace it with c_ptr().
an error
Even after the fix for bug 28701 visible behaviors of
SELECT FROM a view and SELECT FROM a regular table are
little bit different:
1. "SELECT FROM regular table USE/FORCE/IGNORE(non
existent index)" fails with a "ERROR 1176 (HY000):
Key '...' doesn't exist in table '...'"
2. "SELECT FROM view USING/FORCE/IGNORE(any index)" fails
with a "ERROR 1221 (HY000): Incorrect usage of
USE/IGNORE INDEX and VIEW". OTOH "SHOW INDEX FROM
view" always returns empty result set, so from the point
of same behaviour view we trying to use/ignore non
existent index.
To harmonize the behaviour of USE/FORCE/IGNORE(index)
clauses in SELECT from a view and from a regular table the
"ERROR 1221 (HY000): Incorrect usage of USE/IGNORE INDEX
and VIEW" message has been replaced with the "ERROR 1176
(HY000): Key '...' doesn't exist in table '...'" message
like for tables and non existent keys.
The SHOW VARIABLES LIKE .../SELECT @@/SELECT ... FROM INFORMATION_SCHEMA.VARIABLES
were assuming that all the system variables are in system charset (UTF-8).
However the variables that are settable through command line will have a different
character set (character_set_filesystem).
Fixed the server to remember the correct character set of basedir, datadir, tmpdir,
ssl, plugin_dir, slave_load_tmpdir, innodb variables; init_connect and init_slave
variables and use it when processing data.
The bug is repeatable with latest(1.0.1) InnoDB plugin on Linux, Win,
If MySQL is compiled with valgrind there are errors about
using of uninitialized variable(orig_table).
The fix is to set field->orig_table correct value.
enable uncacheable flag if we update a view with check option
and check option has a subselect, otherwise, the check option
can be evaluated after the subselect was freed as independent
(See full_local in JOIN::join_free())
We pretended that TIMEDIFF() would always return positive results;
this gave strange results in comparisons of the TIMEDIFF(low,hi)<TIME(0)
type that rendered a negative result, but still gave false in comparison.
We also inadvertantly dropped the sign when converting times to
decimal.
CAST(time AS DECIMAL) handles signs of the times correctly.
TIMEDIFF() marked up as signed. Time/date comparison code switched to
signed for clarity.
ONLY_FULL_GROUP_BY
The check for non-aggregated columns in queries with aggregate function, but without
GROUP BY was treating all the parts of the query as if they are in the SELECT list.
Fixed by ignoring the non-aggregated fields in the WHERE clause.
returns truncated results
Problem: performig conversion from {INT, DECIMAL, REAL} to CHAR
we incorrectly set its max length in some cases that may lead
to truncated results returned.
Fix: properly set CONVERT({INT, DECIMAL, REAL}, CHAR) result's
max length.
It was possible to crash a mysqld build with EXTRA_DEBUG using
CREATE TABLE ... COMMENT with a specially-crafted UTF-8 string.
This CS removes the check that caused it since it no longer
applies in current servers anyway, and adds comments instead
to avoid future confusion.
Problem: memory leak occurs when we open a federated table
that has its share in the hash.
Fix: free not used memory.
Note: the fix should NOT be merged to 5.1 (the code changed).
When a CSV file contained comma separated elements
that were not enclosed in quotes, it was causing the
mysql server to crash.
The old algorithm that parsed the content of a row in
mysql 5.0 was assuming that the values of the fields
in a .CSV file will be enclosed in quotes and will be
separated by commas.
This was causing the old algorithm to fail when the
content of the file resembled the following
3,"sans quotes"
The CSV engine that is part of mysql 5.0 was expecting
the above to be
"3","sans quotes"
The above is just one example of where the engine was
failing for what would be recognized as a valid .CSV
file content otherwise.
The proposed fix changes the old algorithm being used
to parse rows from the .CSV file to handle two separate
cases
1) When the current field of the row is enclosed in quotes
2) When the current field of the row is not enclosed in
quotes
Item_func_div didn't calculate the precision of the result properly.
The result of 5/0.0001 is 5000 so we have to add decimals of the divisor
to the planned precision.
per-file comments:
mysql-test/r/type_newdecimal.result
Bug#31616 div_precision_increment description looks wrong
test result fixed
mysql-test/t/type_newdecimal.test
Bug#31616 div_precision_increment description looks wrong
test case
sql/item_func.cc
Bug#31616 div_precision_increment description looks wrong
precision must be increased with args[1]->decimals parameter
missing after downgrade
Obsolete arc/ directory and view .frm file backup support
has been removed by the patch for bug 17823. However, that
bugfix caused a problem with "live downgrades" of the
server: if we rename some view 4 times under 5.1.29/5.0.72
and then try to rename it under 5.1.28/5.0.70 on the same
database, the server fails with a error:
query 'RENAME TABLE ... TO ...' failed: 6: Error on
delete of '....frm-0001' (Errcode: 2)
Also .frm file of that view may be lost (renamed to .frm~).
The server failed because it tried to rename latest 3
backup .frm files renaming the view: the server used an
integer value of the "revision" field of .frm file to
extract those file names. After the fix for bug 17823 those
files were not created/maintained any more, however the
"revision" field was incremented as usual. So, the server
failed renaming non existent files.
This fix solves the problem by removing the support for
"revision" .frm file field:
1. New server silently ignores existent "revision" fields
in old .frm files and never write it down;
2. Old server assumes, that missing "revision" field in new
.frm files means default value of 0.
3. Accordingly to the fix for bug 17823 the new server
drops arc/ directory on alter/rename view, so after
"live downgrade" old server begins maintenance of the
arc/ directory from scratch without conflicts with .frm
files.
status
The problem appears to be a race condition, when service is being
stopped right after startup. We set the service status to SERVICE_RUNNING
way too early it cannot yet handle stop requests - initialization has
not finished and hEventShutdown that signals server to stop is not yet
created. If somebody issues "net stop MySQL" at this time, MySQL is not
informed about the stop and continues to run as usual, while
NTService::ServiceMain() stucks forever waiting for mysql's "main" thread
to finish.
Solution is to remain in SERVICE_START_PENDING status until after server
initialization is fully complete and only then change the status to
SERVICE_RUNNING. In SERVICE_START_PENDING we do not accept service control
requests, i.e it is not possible to stop service in that time.
I think we don't need to issue an error statement in the convert_search_mode_to_innobase().
Returning the PAGE_CUR_UNSUPP value is enough as allows to handle this
case depending on the requirements.
per-file comments:
sql/ha_innodb.cc
Bug#31435 ha_innodb.cc:3983: ulint convert_search_mode_to_innobase(ha_rkey_function): Asse
no error issued in convert_search_mode_to_innobase.
ha_innobase::records_in_range() returns HA_POS_ERROR if search mode isn't supported.
With fix for bug 25951 index hints are ignored for fulltext
searches, as handling of fulltext indexes is different from
handling regular indexes. Meaning it is not possible to
implement true index hints support for fulltext indexes within
the scope of current fulltext architecture.
The problem is that prior to fix for bug 25951, some useful
index hints still could be given for boolean mode searches.
This patch implements special index hints support for fulltext
indexes with the following characteristics:
- all index hints are still ignored for NLQ mode searches -
it cannot work without an index;
- for 5.1 and up index hints FOR ORDER BY and FOR GROUP BY are
still ignored for fulltext indexes;
- boolean mode searches honor USE/FORCE/IGNORE INDEX hints;
- as opposed to index hints for regular indexes, index hints
for fulltext BOOLEAN mode searches affect the usage of the
index for the whole query.
A string buffers which were included in the 'view' data structure
were allocated on the stack, causing an invalid pointer when used
after the function returned.
The fix: use copy of values for view->md5 & view->queries
- Make send_row_on_empty_set() return FALSE when simplify_cond() has found out
that HAVING is always FALSE
re-committing to put the fix into 5.0 and 5.1
Visual Studio 2008 Express edition does not include message compiler mc.exe
It is not possible to build MySQL server if only VC2008 Express is installed,
because we use mc.exe to generate event log messages.
This patch removes the mc.exe dependency. Generated files message.h,
message.rc and MSG00001.bin are checked into source code repository.
Instructions on how to add or change messages are added to messages.mc
The problem was that the server did not robustly handle a
unilateral roll back issued by the Resource Manager (RM)
due to a resource deadlock within the transaction branch.
By not acknowledging the roll back, the server (TM) would
eventually corrupt the XA transaction state and crash.
The solution is to mark the transaction as rollback-only
if the RM indicates that it rolled back its branch of the
transaction.
fails after the first time
Two separate problems :
1. When flattening joins the linked list used for name resolution
(next_name_resolution_table) was not updated.
Fixed by updating the pointers when extending the table list
2. The items created by expanding a * (star) as a column reference
were marked as fixed, but no cached table was assigned to them
(unlike what Item_field::fix_fields does).
Fixed by assigning a cached table (so the re-preparation is done
faster).
Note that the fix for #2 hides the fix for #1 in most cases
(except when a table reference cannot be cached).
IS NULL was not checking the correct row in a HAVING context.
At the first row of a new group (where the HAVING clause is evaluated)
the column and SELECT list references in the HAVING clause should
refer to the last row of the previous group and not to the current one.
This was not done for IS NULL, because it was using Item::is_null() doesn't
have a Item_is_null_result() counterpart to access the data from the
last row of the previous group. Note that all the Item::val_xxx() functions
(e.g. Item::val_int()) have their _result counterparts (e.g. Item::val_int_result()).
Fixed by implementing a is_null_result() (similarly to int_result()) and
calling this instead of is_null() column and SELECT list references inside
the HAVING clause.
Server crashed during a sort order optimization
of a dependent subquery:
SELECT
(SELECT t1.a FROM t1, t2
WHERE t1.a = t2.b AND t2.a = t3.c
ORDER BY t1.a)
FROM t3;
Bitmap of tables, that the reference to outer table
column uses, in addition to the regular table bit
has the OUTER_REF_TABLE_BIT bit set.
The only_eq_ref_tables function traverses this map
bit by bit simultaneously with join->map2table list.
Obviously join->map2table never contains an entry
for the OUTER_REF_TABLE_BIT pseudo-table, so the
server crashed there.
The only_eq_ref_tables function has been modified
to traverse regular table bits only like the
update_depend_map function (resetting of the
OUTER_REF_TABLE_BIT there is enough, but
resetting of the whole set of PSEUDO_TABLE_BITS
is used there for sure).
The problem is that the offset argument of the limit clause
might be truncated on a 32-bits server built without big
tables support. The truncation was happening because the
original 64-bits long argument was being cast to a 32-bits
(ha_rows) offset counter.
The solution is to check if the conversing resulted in value
truncation and if so, the offset is set to the maximum possible
value that can fit on the type.
If delayed insert fails to upgrade the lock it was not
freeing the temporary memory storage used to keep
newly constructed blob values in memory.
Fixed by iterating over the remaining rows in the delayed
insert rowset and freeing the blob storage for each row.
No test suite because it involves concurrent delayed inserts
on a table and cannot easily be made deterministic.
Added a correct valgrind suppression for Fedora 9.
The problem is that field names constructed due to wild-card
expansion done inside a stored procedure could point to freed
memory if the expansion was performed after the first call to
the stored procedure.
The problem was solved by patch for Bug#38691. The solution
was to allocate the database, table and field names in the
in the statement memory instead of table memory.
The query cache module did not check for the SQL_NO_CACHE keyword before
attempting to query the hash lookup table. This had a small performance impact.
By introducing a check on the query string before obtaining the hash mutex
we can gain some performance if the SQL_NO_CACHE directive is used often.
Select with a "NULL NOT IN" condition containing complex
subselect from the same table as in the outer select failed
with an assertion.
The failure was caused by a concatenation of circumstances:
1) an inner select was optimized by make_join_statistics to use
the QUICK_RANGE_SELECT access method (that implies an index
scan of the table);
2) a subselect was independent (constant) from the outer select;
3) a condition was pushed down into inner select.
During the evaluation of a constant IN expression an optimizer
temporary changed the access method from index scan to table
scan, but an engine handler was already initialized for index
access by make_join_statistics. That caused an assertion.
Unnecessary index initialization has been removed from
the QUICK_RANGE_SELECT::init method (QUICK_RANGE_SELECT::reset
reinvokes this initialization).
with COALESCE and JOIN
The server returned to a client the VARBINARY column type
instead of the DATE type for a result of the COALESCE,
IFNULL, IF, CASE, GREATEST or LEAST functions if that result
was filesorted in an anonymous temporary table during
the query execution.
For example:
SELECT COALESCE(t1.date1, t2.date2) AS result
FROM t1 JOIN t2 ON t1.id = t2.id ORDER BY result;
To create a column of various date/time types in a
temporary table the create_tmp_field_from_item() function
uses the Item::tmp_table_field_from_field_type() method
call. However, fields of the MYSQL_TYPE_NEWDATE type were
missed there, and the VARBINARY columns were created
by default.
Necessary condition has been added.
derived table cause crash
When a multi-UPDATE command fails to lock some table, and
subsequently succeeds, the tables need to be reopened if
they were altered. But the reopening procedure failed for
derived tables.
Extra cleanup has been added.
When running Stored Routines the Status Variable "Questions" was wrongly
incremented. According to the manual it should contain the "number of
statements that clients have sent to the server"
Introduced a new status variable 'questions' to replace the query_id
variable which currently corresponds badly with the number of statements
sent by the client.
The new behavior is ment to be backward compatible with 4.0 and at the
same time work with new features in a similar way.
This is a backport from 6.0
``FLUSH TABLES WITH READ LOCK''
Concurrent execution of 1) multitable update with a
NATURAL/USING join and 2) a such query as "FLUSH TABLES
WITH READ LOCK" or "ALTER TABLE" of updating table led
to a server crash.
The mysql_multi_update_prepare() function call is optimized
to lock updating tables only, so it postpones locking to
the last, and if locking fails, it does cleanup of modified
syntax structures and repeats a query analysis. However,
that cleanup procedure was incomplete for NATURAL/USING join
syntax data: 1) some Field_item items pointed into freed
table structures, and 2) the TABLE_LIST::join_columns fields
was not reset.
Major change:
short-living Field *Natural_join_column::table_field has
been replaced with long-living Item*.
The '@' symbol can not be used in the host name according to rfc952.
The fix:
added function check_host_name(LEX_STRING *str)
which checks that all symbols in host name string are valid and
host name length is not more than max host name length
(just moved check_string_length() function from the parser into check_host_name()).
The problem:
I_S views table does not check the presence of SHOW_VIEW_ACL|SELECT_ACL
privileges for a view. It leads to discrepancy between SHOW CREATE VIEW
and I_S.VIEWS.
The fix:
added appropriate check.
When analyzing the possible index use cases the server was re-using an internal structure.
This is wrong, as this internal structure gets updated during the analysis.
Fixed by making a copy of the internal structure for every place it needs to be used.
Also stopped the generation of empty SEL_TREE structures that unnecessary
complicate the analysis.
