COLUMNS IN VIEWS
Issue:
charset value for a Column, returned by MYSQL_LIST_FIELDS(), was not same
for Table and View. This was because, for view, field charset was not being
returned.
Solution:
Added definition of function "charset_for_protocol()" in calss
Item_ident_for_show to return field charset value.
This test case was failing on 5.5 and trunk for two reasons.
1) It waited for the "Waiting for table level lock" process
state while this state was renamed "Waiting for table
metadata lock" with the introduction of MDL in 5.5.
2) SET GLOBAL query_cache_size= 100000; gave a warning since
query_cache_size is supposed to be multiples of 1024.
This patch fixes these two issues and re-enables the test case.
RESULT CONSISTED OF MORE THAN ONE ROW
MySQL converts incorrect DATEs and DATETIMEs to '0000-00-00' on
insertion by default. This means that this sequence is possible:
CREATE TABLE t1(date_notnull DATE NOT NULL);
INSERT INTO t1 values (NULL);
SELECT * FROM t1;
0000-00-00
At the same time, ODBC drivers do not (or at least did not in the
90's) understand the DATE and DATETIME value '0000-00-00'. Thus,
to be able to query for the value 0000-00-00 it was decided in
MySQL 4.x (or maybe even before that) that for the special case
of DATE/DATETIME NOT NULL columns, the query "SELECT ... WHERE
date_notnull IS NULL" should return rows with date_notnull ==
'0000-00-00'. This is documented misbehavior that we do not want
to change.
The hack used to make MySQL return these rows is to convert
"date_notnull IS NULL" to "date_notnull = 0". This is, however,
only done if the table date_notnull belongs to is not an inner
table of an outer join. The rationale for this seems to be that
if there is no join match for the row in the outer table,
null-complemented rows would otherwise not be returned because
the null-complemented DATE value is actually NULL. On the other
hand, this means that the "return rows with 0000-00-00 when the
query asks for IS NULL"-hack is not in effect for outer joins.
In this bug, we have a LEFT JOIN that does not misbehave like
the documentation says it should. The fix is to rewrite
"date_notnull IS NULL" to "date_notnull IS NULL OR
date_notnull = 0"
if dealing with an OUTER JOIN, otherwise
"date_notnull IS NULL" to "date_notnull = 0"
as was done before.
Note:
The bug was originally reported as different result on first
and second execution of SP. The reason was that during first
execution the query was correctly rewritten to an inner join
due to a null-rejecting predicate. On second execution the
"IS NULL" -> "= 0" rewrite was done because there was no outer
join. The real problem, though, was incorrect date/datetime
IS NULL handling for OUTER JOINs.
SYNTAX TRIGGERS IN ANY WAY
Table with triggers which were using deprecated (5.0-only) syntax became
unavailable for any DML and DDL after upgrade to 5.1 version of server.
Attempt to execute any statement on such a table resulted in parsing
error reported. Since this included DROP TRIGGER and DROP TABLE
statements (actually, the latter was allowed but was not functioning
properly for such tables) it was impossible to fix the problem without
manual operations on .TRG and .TRN files in data directory.
The problem was that failure to parse trigger body (due to 5.0-only
syntax) when opening trigger file for a table prevented the table
from being open. This made all operations on the table impossible
(except DROP TABLE which due to peculiarity in its implementation
dropped the table but left trigger files around).
This patch solves this problem by silencing error which occurs when
we parse trigger body during table open. Error message is preserved
for the future use and table is marked as having a broken trigger.
We also try to analyze parse tree to recover trigger name, which
will be needed in order to drop the broken trigger. DML statements
which invoke triggers on the table marked as having broken trigger
are prohibited and emit saved error message. The same happens for
DDL which change triggers except DROP TRIGGER and DROP TABLE which
try their best to do what was requested. Table becomes no longer
marked as having broken trigger when last such trigger is dropped.
THE EVENT STATUS.
Any ALTER EVENT statement on a disabled event enabled it back
(unless this ALTER EVENT statement explicitly disabled the event).
The problem was that during processing of an ALTER EVENT statement
value of status field was overwritten unconditionally even if new
value was not specified explicitly. As a consequence this field
was set to default value for status which corresponds to ENABLE.
The solution is to check if status field was explicitly specified in
ALTER EVENT statement before assigning new value to status field.
SEEMS TO BE 'LEAKING' INTO THE SCHEMA NAME SPACE)
and bug#12428824 (Parser stack overflow and crash in sp_add_used_routine
with obscure query).
The first problem was that attempts to call a stored function by
its fully qualified name ended up with unwarranted error "ERROR 1305
(42000): FUNCTION someMixedCaseDb.my_function_name does not exist"
if this function belonged to a schema that had uppercase letters in
its name AND --lower_case_table_names was equal to either 1 or 2.
The second problem was that 5.5 version of MySQL server might have
crashed when a user tried to call stored function with too long name
or too long database name (i.e if a function and database name combined
occupied more than 2*3*64 bytes in utf8). This issue didn't affect
versions of server < 5.5.
The first problem was caused by the fact that in cases when a stored
function was called by its fully qualified name we didn't lowercase
name of its schema before performing look up of the function in
mysql.proc table even although lower_case_table_names mode was on.
As result we were unable to find this function since during its
creation we store lowercased version of schema name in the system
table in this mode and field for schema name uses binary collation.
Calls to stored functions were unaffected by this problem since for
them schema name is converted to lowercase as necessary.
The reason for the second bug was that MySQL Server didn't check length
of function name and database name before proceeding with execution of
stored function. As a consequence too long database name or function
name caused buffer overruns in places where the code assumes that their
length is within fixed limits, like mdl_key_init() in 5.5.
Again this issue didn't affect calls to stored procedures as for them
length of schema name and procedure name are properly checked.
This patch fixes both these bugs by adding calls to check_db_name()
and check_routine_name() to grammar rule which corresponds to a call
to a stored function. These functions ensure that length of database
name and function name for routine called is within standard limit.
Moreover call to check_db_name() handles conversion of database name
to lowercase if --lower_case_table_names mode is on.
Note that even although the second issue seems to be only reproducible
in 5.5 we still add code fixing it to 5.1 to be on the safe side (and
make code a bit more robust against possible future changes).
STATEMENTS FAIL".
Attempt to execute CREATE TABLE LIKE statement on a MyISAM
table with INDEX or DATA DIRECTORY options specified as a
source resulted in "MyISAM table '...' is in use..." error.
According to our documentation such a statement should create
a copy of source table with DATA/INDEX DIRECTORY options
omitted.
The problem was that new implementation of CREATE TABLE LIKE
statement in 5.5 tried to copy value of INDEX and DATA DIRECTORY
parameters from the source table. Since in description of source
table this parameters also included name of this table, attempt
to create target table with these parameter led to file name
conflict and error.
This fix addresses the problem by preserving documented and
backward-compatible behavior. I.e. by ensuring that contents
of DATA/INDEX DIRECTORY clauses for the source table is
ignored when target table is created.
If UNIV_DEBUG or UNIV_BLOB_LIGHT_DEBUG is enabled, add
!rec_offs_any_null_extern() assertions, ensuring that records do not
contain null pointers to externally stored columns in inappropriate
places.
btr_cur_optimistic_update(): Assert !rec_offs_any_null_extern().
Incomplete records must never be updated or deleted. This assertion
will cover also the pessimistic route.
row_build(): Assert !rec_offs_any_null_extern(). Search tuples must
never be built from incomplete index entries.
row_rec_to_index_entry(): Assert !rec_offs_any_null_extern() unless
ROW_COPY_DATA is requested. ROW_COPY_DATA is used for
multi-versioning, and therefore it might be valid to copy the most
recent (uncommitted) version while it contains a null pointer to
off-page columns.
row_vers_build_for_consistent_read(),
row_vers_build_for_semi_consistent_read(): Assert !rec_offs_any_null_extern()
on all versions except the most recent one.
trx_undo_prev_version_build(): Assert !rec_offs_any_null_extern() on
the previous version.
rb:682 approved by Sunny Bains
FUNCTION DOES NOT EXIST IF NOT-PRIV USER RECONNECTS".
The bug itself was fixed by the same patch as bug@11747137
"30977: CONCURRENT STATEMENT USING STORED FUNCTION AND DROP
FUNCTION BREAKS SBR".
Problem: in case of wrong data insert into indexed GEOMETRY fields
(e.g. NULL value for a not NULL field) MyISAM reported
"ERROR 126 (HY000): Incorrect key file for table; try to repair it"
due to misuse of the key deletion function.
Fix: always use R-tree key functions for R-tree based indexes
and B-tree key functions for B-tree based indexes.
This is the 5.1 version of the fix.
Need to free the memory allocated by the option parsing code for empty
strings when resetting the pointer to NULL.
No test case needed, as the existing ones already cover this path.
Re-enable a test that was disabled as collateral damage.
Starting with MySQL 5.5, queries will acquire and hold a shared meta-data lock
(MDL) on tables they process, until the transaction is committed or
rolled back. This will prevent DDL operations on the tables, such as creating
an index.
innodb-index.test: Use a second table for creating the index. The index will
still be "too new" for the transaction that was started before the index
creation was started.
Bug 12430414 - THE TEST PERFSCHEMA.SELECTS.TEST CAN AFFECT SUCCEEDING TESTS
Bug 12430599 - THE TEST PERFSCHEMA.ONE_THREAD_PER_CON. CAN AFFECT SUCCEEDING TESTS
Bug 12431153 - THE TEST PERFSCHEMA.PFS_UPGRADE CAN AFFECT SUCCEEDING TEST
GRADUALLY IF A TRIGGER EXISTS".
This bug manifested itself in two ways:
- Firstly execution of any data-changing statement which
required prelocking (i.e. involved stored function or
trigger) as part of transaction slowed down a bit all
subsequent statements in this transaction. So performance
in transaction which periodically involved such statements
gradually degraded over time.
- Secondly execution of any data-changing statement which
required prelocking as part of transaction prevented
concurrent FLUSH TABLES WITH READ LOCK from proceeding
until the end of transaction instead of end of particular
statement.
The problem was caused by incorrect handling of metadata lock
used in FTWRL implementation for statements requiring prelocked
mode.
Each statement which changes data acquires global IX lock
with STATEMENT duration. This lock is supposed to block
concurrent FTWRL from proceeding until the statement ends.
When entering prelocked mode, durations of all metadata locks
acquired so far were changed to EXPLICIT, to prevent
substatements from releasing these locks. When prelocked mode
was left, durations of metadata locks were changed to
TRANSACTIONAL (with a few exceptions) so they can be properly
released at the end of transaction.
Unfortunately, this meant that the global IX lock blocking
FTWRL with STATEMENT duration was moved to TRANSACTIONAL
duration after execution of statement requiring prelocking.
Since each subsequent statement that required prelocking and
tried to acquire global IX lock with STATEMENT duration got
a new instance of MDL_ticket, which was later moved to
TRANSACTIONAL duration, this led to unwarranted growth of
number of tickets with TRANSACITONAL duration in this
connection's MDL_context. As result searching for other
tickets in it became slow and acquisition of other metadata
locks by this transaction started to hog CPU.
Moreover, this also meant that after execution of statement
requiring prelocking concurrent FTWRL was blocked
until the end of transaction instead of end of statement.
This patch solves this problem by not moving locks to EXPLICIT
duration when thread enters prelocked mode (unless it is a real
LOCK TABLES mode). This step turned out to be not really
necessary as substatements don't try to release metadata locks.
Consequently, the global IX lock blocking FTWRL keeps its
STATEMENT duration and is properly released at the end of
statement and the above issue goes away.
Issue:
------
New test case mysql_embedded.test was failing on pb2.
Description:
------------
To run this test case executable libmysqld/examples/mysql_embedded is required.
But as per /libmysqld/examples/cmake_install.cmake this executable doesn't get
copied to <install_dir> when mysql is installed at <install_dir>.That is the
reason it was passing in my local branch and failed on pb2 when pushed.
Solution;
---------
Added code in mysql-test-run.pl, which will try to see if this file exists.If
It doesn't exist, test case will be skipped with a skip message. New code in
mysql-test-run.pl looks only for directory libmysqld/examples/mysql_embedded
because this is the only place where this file could/does exist.
