TO POSITION FIRST CAN CAUSE DATA TO BE CORRUPTED".
ALTER TABLE MODIFY/CHANGE ... FIRST did nothing except renaming
columns if new version of the table had exactly the same
structure as the old one (i.e. as result of such statement, names
of columns changed their order as specified but data in columns
didn't). The same thing happened for ALTER TABLE DROP COLUMN/ADD
COLUMN statements which were supposed to produce new version of
table with exactly the same structure as the old version of table.
I.e. in the latter case the result was the same as if old column
was renamed instead of being dropped and new column with default
as value being created.
Both these problems were caused by the fact that ALTER TABLE
implementation incorrectly interpreted both these situations as
simple renaming of columns and assumed that in-place ALTER TABLE
algorithm could have been used for them.
This patch fixes this problem by ensuring that in cases when some
column is moved to the first position or some column is dropped
the default ALTER TABLE algorithm involving table copying is
always used. This is achieved by detecting such situations in
mysql_prepare_alter_table() and setting Alter_info::change_level
to ALTER_TABLE_DATA_CHANGED for them.
mysql-test/r/alter_table.result:
Added test for bug #12652385 - "61493: REORDERING COLUMNS TO
POSITION FIRST CAN CAUSE DATA TO BE CORRUPTED".
mysql-test/t/alter_table.test:
Added test for bug #12652385 - "61493: REORDERING COLUMNS TO
POSITION FIRST CAN CAUSE DATA TO BE CORRUPTED".
sql/sql_table.cc:
Changed mysql_prepare_alter_table() to detect situations in
which we some column moved to the first position or some column
is dropped and ensure that such ALTER TABLE statements won't
be carried out using in-place algorithm. The latter could have
happened before this patch if new version of table had the same
structure as the old one (except the column names).
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.
mysql-test/r/flush.result:
Added test for bug #12641342 - "61401: UPDATE PERFORMANCE
DEGRADES GRADUALLY IF A TRIGGER EXISTS".
mysql-test/t/flush.test:
Added test for bug #12641342 - "61401: UPDATE PERFORMANCE
DEGRADES GRADUALLY IF A TRIGGER EXISTS".
sql/mdl.h:
Added comment describing various types of metadata lock
duration.
sql/sql_class.cc:
Since we no longer change duration of metadata locks to EXPLICIT
when entering prelocked mode (unless it is a real LOCK TABLES)
there is no need to restore proper duration of the locks when
leaving prelocked mode.
sql/sql_class.h:
Do not change duration of metadata locks to EXPLICIT when
entering prelocking mode (unless it is a real LOCK TABLES).
This allows to avoid problems with restoring correct duration
when leaving this mode. It is possible to do this as
substatements won't release metadata locks in any case.
sql/sql_parse.cc:
Added assert checking that we won't release metadata locks
when in substatement.
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.
mysql-test/mysql-test-run.pl:
Added new variable for mysql_embedded executable.
mysql-test/t/disabled.def:
enabled mysql_embedded.test which was disabled earlier.
mysql-test/t/mysql_embedded.test:
Modified test case to first verify if mysql_embedded executable exists. If
it does not, skip the test.
The buf_pool->zip_clean list is only needed for debugging, or for
recomputing buf_pool->page_hash when resizing the buffer pool. Buffer
pool resizing was never fully implemented. Remove the resizing code,
and define buf_pool->zip_clean only in debug builds.
buf_pool->zip_clean, buf_LRU_insert_zip_clean(): Enclose in
#if defined UNIV_DEBUG || UNIV_BUF_DEBUG.
buf_chunk_free(), buf_chunk_all_free(), buf_pool_shrink(),
buf_pool_page_hash_rebuild(), buf_pool_resize(): Remove (unreachable code).
rb:671 approved by Inaam Rana
There is an apparent problem with page_zip_clear_rec().
In btr_cur_optimistic_update() we do this:
page_cur_delete_rec(page_cursor, index, offsets, mtr);
...
rec = btr_cur_insert_if_possible(cursor, new_entry, 0/*n_ext*/, mtr);
ut_a(rec); /* <- We calculated above the insert would fit */
The problem is that page_cur_delete_rec() could fill the modification
log while doing page_zip_clear_rec(), requiring recompression for the
btr_cur_insert_if_possible(). In a pathological case, the data could
fail to recompress.
page_zip_clear_rec(): Leave the page modification log alone. Only
clear the necessary fields.
rb:673 approved by Jimmy Yang
Replace UNIV_BLOB_NULL_DEBUG with UNIV_DEBUG||UNIV_BLOB_LIGHT_DEBUG.
Fix known bogus failures.
btr_cur_optimistic_update(): If rec_offs_any_null_extern(), assert that
the current transaction is an incomplete transaction that is being
rolled back in crash recovery.
row_build(): If rec_offs_any_null_extern(), assert that the transaction
that last updated the record was recovered during crash recovery
(and will soon be rolled back).
btr_cur_compress_if_useful(), btr_compress(): Add the parameter ibool
adjust. If adjust=TRUE, adjust the cursor position after compressing
the page.
btr_lift_page_up(): Return a pointer to the father page.
BTR_KEEP_POS_FLAG: A new flag for btr_cur_pessimistic_update().
btr_cur_pessimistic_update(): If *big_rec != NULL and flags &
BTR_KEEP_POS_FLAG, keep the cursor positioned on the updated record.
Also, do not release the index tree x-lock if *big_rec != NULL.
btr_cur_mtr_commit_and_start(): Commits and restarts a
mini-transaction so that it will retain an x-lock on index->lock and
the page of the cursor. This is invoked when
btr_cur_pessimistic_update() returns *big_rec != NULL.
In all callers of btr_cur_pessimistic_update() that do not pass
BTR_KEEP_POS_FLAG, assert that *big_rec == NULL.
btr_cur_compress(): Unused function [in the built-in MySQL 5.1], remove.
page_rec_get_nth(): Return the nth record on the page (an inverse
function of page_rec_get_n_recs_before()). Refactored from
page_get_middle_rec().
page_get_middle_rec(): Invoke page_rec_get_nth().
page_cur_insert_rec_zip_reorg(): Make use of the page directory
shortcuts in page_rec_get_nth() instead of scanning the whole list of
records.
row_ins_clust_index_entry_by_modify(): Pass BTR_KEEP_POS_FLAG to
btr_cur_pessimistic_update().
row_ins_index_entry_low(): If row_ins_clust_index_entry_by_modify()
returns a big_rec, invoke btr_cur_mtr_commit_and_start() in order to
commit and start the mini-transaction without releasing the x-locks on
index->lock and the cursor page, and write the big_rec. Releasing the
page latch in mtr_commit() caused a race condition.
row_upd_clust_rec(): Pass BTR_KEEP_POS_FLAG to
btr_cur_pessimistic_update(). If it returns a big_rec, invoke
btr_cur_mtr_commit_and_start() in order to commit and start the
mini-transaction without releasing the x-locks on index->lock and the
cursor page, and write the big_rec. Releasing the page latch in
mtr_commit() caused a race condition.
sync_thread_add_level(): Add the parameter ibool relock. When TRUE,
bypass the latching order rules.
rw_lock_add_debug_info(): For nested X-lock requests, pass relock=TRUE
to sync_thread_add_level().
rb:678 approved by Jimmy Yang
UPDATED TWICE
For multi update it is not allowed to update a column
of a table if that table is accessed through multiple aliases
and either
1) the updated column is used as partitioning key
2) the updated column is part of the primary key
and the primary key is clustered
This check is done in unsafe_key_update().
The bug was that for case 2), it was checked whether
updated_column_number == table_share->primary_key
However, the primary_key variable is the index number of the
primary key, not a column number.
Prior to this bugfix, the first column was wrongly believed to be
the primary key. The columns covered by an index is found in
table->key_info[idx_number]->key_part. The bugfix is to check if
any of the columns in the keyparts of the primary key are
updated.
The user-visible effect is that for storage engines with
clustered primary key (e.g. InnoDB but not MyISAM) queries
like
"UPDATE t1 AS A JOIN t2 AS B SET A.primkey=..."
will now error with
"ERROR HY000: Primary key/partition key update is not allowed
since the table is updated both as 'A' and 'B'."
instead of
"ERROR 1032 (HY000): Can't find record in 't1_tb'"
even if primkey is not the first column in the table. This
was the intended behavior of bugfix 11764529.
mysql-test/r/multi_update.result:
Add test for bug#11882110
mysql-test/r/multi_update_innodb.result:
Add test for bug#11882110
mysql-test/t/multi_update.test:
Add test for bug#11882110
mysql-test/t/multi_update_innodb.test:
Add test for bug#11882110
sql/sql_update.cc:
unsafe_key_update() wrongly checked if the primary key index
number was the same as updated column number. Now it is checked
whether any of the columns making up the primary key is updated.
sql/table.h:
Fix comment on TABLE_SHARE::primary_key. Incorrect comment
was introduced by an earlier merge conflict (as per dlenev)
can't parse relative paths "higher" than 3 levels up
When trying to LOAD DATA LOCAL INFILE using a relative path with 3 or
more levels up in the directory hierarchy, mysqld wrongly parses
the path and as a consequence, can't find the file.
This bug was introduced by patch for bug#58205.
The reason for bug is that implementaiton of function cleanup_dirname()
doesn't take into account the begin of buffer being processed during
handling of path to file.
mysys/mf_pack.c:
function cleanup_dirname() was modified: fixed wrong comparison
condition when handling substring "../" at the begining of the buffer.
Some ut_a(!rec_offs_any_null_extern()) assertion failures are indicating
genuine BLOB bugs, others are bogus failures when rolling back incomplete
transactions at crash recovery. This needs more work, and until I get a
chance to work on it, other testing must not be disrupted by this.
Issue:
When libmysqld/example/mysql_embedded is executed, it was getting abort. Its a
regression as it was working in 5.1 and failed in 5.5. Issue is there because
remaining_argc/remaining_argv were not getting assigned correctly in
init_embedded_server() which were being used later in init_common_variable().
Solution:
Rectified code to pass correct argc/argv to be used in init_common_variable().
libmysqld/lib_sql.cc:
Rectified remaining_argc/remaining_argv assignment.
mysql-test/r/mysql_embedded.result:
Result file for the test case added.
mysql-test/t/mysql_embedded.test:
Added test case to verify libmysqld/example/mysql_embedded works.
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.
sql/item.h:
Added definition for charset_for_protocol() function to return field charset.
tests/mysql_client_test.c:
Added a test case test_bug12337762 for the changes done.
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.
mysql-test/r/type_datetime.result:
Add test for BUG#12561818
mysql-test/t/type_datetime.test:
Add test for BUG#12561818
sql/sql_select.cc:
Special handling of NULL for DATE/DATETIME NOT NULL columns:
In the case of outer join,
"date_notnull IS NULL"
is now rewritten to
"date_notnull IS NULL OR date_notnull = 0"
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.
mysql-test/r/trigger-compat.result:
Add results for test case for bug#45235
mysql-test/t/trigger-compat.test:
Add test case for bug#45235.
sql/sp_head.cc:
Added protection against MEM_ROOT double restoring to
sp_head::restore_thd_mem_root() method. Since this
method can be sometimes called twice during parsing
of stored routine (the first time during normal flow
of parsing, and the second time when a syntax error
is detected) we need to shortcut execution of the
method to avoid damaging MEM_ROOT by the second
consecutive call to this method.
sql/sql_trigger.cc:
Added error handler Deprecated_trigger_syntax_handler to
catch non-OOM errors during parsing of trigger body.
Added handling of parse errors into method
Table_triggers_list::check_n_load().
sql/sql_trigger.h:
Added new members to handle broken triggers and error messages.
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.
mysql-test/r/events_bugs.result:
test's result for Bug#11764334 was added.
mysql-test/t/events_bugs.test:
new test for Bug#11764334 was added.
sql/event_db_repository.cc:
mysql_event_fill_row() was modified: set value for status field
in events tables only in case if statement CREATE EVENT
is being processed or if this value was set in ALTER EVENT
statement.
Event_db_repository::create_event was modified: removed redundant
setting of status field after return from call to mysql_event_fill_row().
sql/event_parse_data.h:
Event_parse_data structure was modified: added flag
status_changed that is set to true if status's value
was changed in ALTER EVENT statement.
sql/sql_yacc.yy:
Set flag status_changed if status was set in ALTER EVENT
statement.
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.
mysql-test/r/symlink.result:
Added test for bug #11759990 - "52354: 'CREATE TABLE ..
LIKE ... ' STATEMENTS FAIL".
mysql-test/t/symlink.test:
Added test for bug #11759990 - "52354: 'CREATE TABLE ..
LIKE ... ' STATEMENTS FAIL".
sql/sql_table.cc:
Changed CREATE TABLE LIKE implementation to ignore contents
of DATA/INDEX DIRECTORY clauses for source table when target
table is created. This is documented and backward-compatible
behavior.
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.
mysql-test/r/gis-rtree.result:
Bug#11764487: myisam corruption with insert ignore and invalid spatial data
- test result.
mysql-test/t/gis-rtree.test:
Bug#11764487: myisam corruption with insert ignore and invalid spatial data
- test case.
storage/myisam/mi_update.c:
Bug#11764487: myisam corruption with insert ignore and invalid spatial data
- handling update errors check for HA_ERR_NULL_IN_SPATIAL as well to be
consistent with mi_write();
- always use keyinfo->ck_delete()/ck_insert() instead of _mi_ck_delete()/_mi_ck_write()
to handle index properly, as it may be of B-tree or R-tree type.
storage/myisam/mi_write.c:
Bug#11764487: myisam corruption with insert ignore and invalid spatial data
- always use keyinfo->ck_delete() instead of _mi_ck_delete() to handle
index properly, as it may be of B-tree or R-tree type.
