causes incorrect duplicate entries
Keys for BTREE indexes on ENUM and SET columns of MEMORY tables
with character set UTF8 were computed incorrectly. Many
different column values got the same key value.
Apart of possible performance problems, it made unique indexes
of this type unusable because it rejected many different
values as duplicates.
The problem was that multibyte character detection was tried
on the internal numeric column value. Many values were not
identified as characters. Their key value became blank filled.
Thanks to Alexander Barkov and Ramil Kalimullin for the patch,
which sets the character set of ENUM and SET key segments to
the pseudo binary character set.
mysql-test/r/heap_btree.result:
Bug#24985 - UTF8 ENUM primary key on MEMORY using BTREE
causes incorrect duplicate entries
Added test result.
mysql-test/t/heap_btree.test:
Bug#24985 - UTF8 ENUM primary key on MEMORY using BTREE
causes incorrect duplicate entries
Added test.
sql/ha_heap.cc:
Bug#24985 - UTF8 ENUM primary key on MEMORY using BTREE
causes incorrect duplicate entries
Set key segment charset to my_charset_bin for ENUM and SET
columns.
Using a MEMORY table BTREE index for scanning for updatable rows
could lead to an infinite loop.
Everytime a key was inserted into a btree index, the position
in the index scan was cleared. The search started from the
beginning and found the same key again.
Now we do not clear the position on key insert an more.
heap/hp_write.c:
Bug#26996 - Update of a Field in a Memory Table ends with wrong result
Removed the index-scan-breaking nulling of last_pos.
The comment behind this line ("For heap_rnext/heap_rprev")
was misleading. It should have been "Breaks heap_rnext/heap_rprev".
mysql-test/r/heap_btree.result:
Bug#26996 - Update of a Field in a Memory Table ends with wrong result
Added test result.
mysql-test/t/heap_btree.test:
Bug#26996 - Update of a Field in a Memory Table ends with wrong result
Added test.
when index is used
When the table contained TEXT columns with empty contents
('', zero length, but not NULL) _and_ strings starting with
control characters like tabulator or newline, the empty values
were not found in a "records in range" estimate. Hence count(*)
missed these records.
The reason was a different set of search flags used for key
insert and key range estimation.
I decided to fix the set of flags used in range estimation.
Otherwise millions of databases around the world would require
a repair after an upgrade.
The consequence is that the manual must be fixed, which claims
that TEXT columns are compared with "end space padding". This
is true for CHAR/VARCHAR but wrong for TEXT. See also bug 21335.
myisam/mi_range.c:
Bug#26231 - select count(*) on myisam table returns wrong value
when index is used
Added SEARCH_UPDATE to the search flags so that it compares
like write/update/delete operations do. Only so it expects
the keys at the place where they have been inserted.
myisam/mi_search.c:
Bug#26231 - select count(*) on myisam table returns wrong value
when index is used
Added some comments to explain how _mi_get_binary_pack_key()
works.
mysql-test/r/myisam.result:
Bug#26231 - select count(*) on myisam table returns wrong value
when index is used
Added a test.
mysql-test/t/myisam.test:
Bug#26231 - select count(*) on myisam table returns wrong value
when index is used
Added test result.
TABLE ... WRITE".
CPU hogging occured when connection which had to wait for table lock was
serviced by thread which previously serviced connection that was killed
(note that connections can reuse threads if thread cache is enabled).
One possible scenario which exposed this problem was when thread which
provided binlog dump to replication slave was implicitly/automatically
killed when the same slave reconnected and started pulling data through
different thread/connection.
In 5.* versions memory hogging was added to CPU hogging. Moreover in
those versions the problem also occured when one killed particular query
in connection (using KILL QUERY) and later this connection had to wait for
some table lock.
This problem was caused by the fact that thread-specific mysys_var::abort
variable, which indicates that waiting operations on mysys layer should
be aborted (this includes waiting for table locks), was set by kill
operation but was never reset back. So this value was "inherited" by the
following statements or even other connections (which reused the same
physical thread). Such discrepancy between this variable and THD::killed
flag broke logic on SQL-layer and caused CPU and memory hogging.
This patch tries to fix this problem by properly resetting this member.
There is no test-case associated with this patch since it is hard to test
for memory/CPU hogging conditions in our test-suite.
sql/mysqld.cc:
We should not forget to reset THD::mysys_var::abort after kill operation
if we are going to use thread to which this operation was applied for
handling of other connections.
my_seek: Assertion `fd != -1' failed"
In difficult optimize/repair situations the server could crash.
Under some circumstances the server retries an optimize/repair
with more elaborate options. But it did not check if the first
attempt failed so badly that a second one must not be tried.
This could happen when a new data file has been created
but it was not possible to open it. In this case the
repair leaves behind a table with closed data file.
This must not be used for another repair attempt.
We do now detect the closed data file and do not try
another repair attempt in this situation.
No test case. The required table corruption can not be
repeated easily. There is a test program attached to
bug 25433.
sql/ha_myisam.cc:
Bug#25289 - repair table causes "my_seek.c:56:
my_seek: Assertion `fd != -1' failed"
Added code to detect a closed data file. It could be closed
by a preceeding repair attempt. We must not try another
repair then.
differences in tables
Certain merge tables were wrongly reported as having incorrect definition:
- Some fields that are 1 byte long (e.g. TINYINT, CHAR(1)), might
be internally casted (in certain cases) to a different type on a
storage engine layer. (affects 4.1 and up)
- If tables in a merge (and a MERGE table itself) had short VARCHAR column (less
than 4 bytes) and at least one (but not all) tables were ALTER'ed (even to an
identical table: ALTER TABLE xxx ENGINE=yyy), table definitions went ouf of
sync. (affects 4.1 only)
This is fixed by relaxing a check for underlying conformance and setting
field type to FIELD_TYPE_STRING in case varchar is shorter than 4
when a table is created.
myisam/mi_create.c:
Added a comment.
mysql-test/r/merge.result:
A test case for bug#26881.
mysql-test/t/merge.test:
A test case for bug#26881.
sql/ha_myisam.cc:
Relaxed some checks performed by check_definition():
As comparing of fulltext keys (and key segments) is not yet implemented,
only return an error in case one of keys is fulltext and other is not.
Otherwise, if both keys are fulltext, accept them as is.
As comparing of spatial keys (and key segments) is not yet implemented,
only return an error in case one of keys is spatial and other is not.
Otherwise, if both keys are spatial, accept them as is.
A workaround to handle situation when field is casted from FIELD_SKIP_ZERO
to FIELD_NORMAL. This could happen only in case field length is 1 and row
format is fixed.
sql/sql_parse.cc:
When a table that has varchar field shorter than 4 is created, field type is
set to FIELD_TYPE_VAR_STRING. Later, when a table is modified using alter
table, field type is changed to FIELD_TYPE_STRING (see Field_string::type).
That means HA_OPTION_PACK_RECORD flag might be lost and thus null_bit might
be shifted by alter table, in other words alter table doesn't create 100%
equal table definition.
This is usually not a problem, since when a table is created/altered,
definition on a storage engine layer is based on one that is passed from
sql layer. But it is a problem for merge engine - null_bit is shifted when
a table (merge or underlying) is altered.
Set field type to FIELD_TYPE_STRING in case FIELD_TYPE_VAR_STRING is shorter
than 4 when a table is created as it is done in Field::type.
incorrect key file for table
In certain cases it could happen that deleting a row could
corrupt an RTREE index.
According to Guttman's algorithm, page underflow is handled
by storing the page in a list for later re-insertion. The
keys from the stored pages have to be inserted into the
remaining pages of the same level of the tree. Hence the
level number is stored in the re-insertion list together
with the page.
In the MySQL RTree implementation the level counts from zero
at the root page, increasing numbers for levels down the tree.
If during re-insertion of the keys the tree height grows, all
level numbers become invalid. The remaining keys will be
inserted at the wrong level.
The fix is to increment the level numbers stored in the
reinsert list after a split of the root block during reinsertion.
myisam/rt_index.c:
Bug#25673 - spatial index corruption, error 126
incorrect key file for table
Added a loop in rtree_delete() to increment the level numbers
stored in the reinsert list after a split of the root block
during reinsertion.
Added comments and DBUG statements.
myisam/rt_key.c:
Bug#25673 - spatial index corruption, error 126
incorrect key file for table
Added DBUG statements.
myisam/rt_split.c:
Bug#25673 - spatial index corruption, error 126
incorrect key file for table
Added DBUG statements.
mysql-test/r/gis-rtree.result:
Bug#25673 - spatial index corruption, error 126
incorrect key file for table
Added the test result.
mysql-test/t/gis-rtree.test:
Bug#25673 - spatial index corruption, error 126
incorrect key file for table
Added a test.
Using INSERT DELAYED on MERGE tables could lead to table
corruptions.
The manual lists a couple of storage engines, which can be
used with INSERT DELAYED. MERGE is not in this list.
The attempt to try it anyway has not been rejected yet.
This bug was not detected earlier as it can work under
special circumstances. Most notable is low concurrency.
To be safe, this patch rejects any attempt to use INSERT
DELAYED on MERGE tables.
mysql-test/r/merge.result:
Bug#26464 - insert delayed + update + merge = corruption
Added test result.
mysql-test/t/merge.test:
Bug#26464 - insert delayed + update + merge = corruption
Added test.
sql/ha_myisammrg.h:
Bug#26464 - insert delayed + update + merge = corruption
Removed HA_CAN_INSERT_DELAYED flag from table_flags().
The insert delayed thread upgrades the lock from the first
entry in MYSQL_LOCK::locks only. Hence it is incapable to
handle MERGE tables, which have as many entries in this
array as they have MyISAM sub-tables.
- Add --debugger=dbx
- Fix --debugger=devenv, --debugger=DevEnv and --debugger=/path/devenv
mysql-test/mysql-test-run.pl:
Add support for --debugger=dbx to mysql-test-run.pl
Fix case senitive match for vc, vcexpress or deven
Make it possible to use full path to debugger for
--debugger=/path/vcexpress
When the ORDER BY clause gets fixed it's allowed to search in the current
item_list in order to find aliased fields and expressions. This is ok for a
SELECT but wrong for an UPDATE statement. If the ORDER BY clause will
contain a non-existing field which is mentioned in the UPDATE set list
then the server will crash due to using of non-existing (0x0) field.
When an Item_field is getting fixed it's allowed to search item list for
aliased expressions and fields only for selects.
sql/sql_base.cc:
Bug#25126: Wrongly resolved field leads to a crash.
When an Item_field is getting fixed it's allowed to search item list for
aliased expressions and fields only for selects.
sql/sql_select.cc:
Bug#25126: Wrongly resolved field leads to a crash.
When an Item_field is getting fixed it's allowed to search item list for
aliased expressions and fields only for selects.
mysql-test/r/update.result:
Added a test case for bug#25126: Wrongly resolved field leads to a crash.
mysql-test/t/update.test:
Added a test case for bug#25126: Wrongly resolved field leads to a crash.
