UPDATES THE TABLE ENTRIES (formerly 55385)
BUG#11764529: MULTI UPDATE+INNODB REPORTS ER_KEY_NOT_FOUND
IF A TABLE IS UPDATED TWICE (formerly 57373)
If multiple-table update updates a row through two aliases and
the first update physically moves the row, the second update will
fail to locate the row. This results in different errors
depending on storage engine:
* MyISAM: Got error 134 from storage engine
* InnoDB: Can't find record in 'tbl'
None of these errors accurately describe the problem.
Furthermore, since MyISAM is non-transactional, the update
executed first will be performed while the second will not.
In addition, for two equal multiple-table update statements,
one could succeed and the other fail based on whether or not
the record actually moved or not. This was inconsistent.
Two update operations may physically move a row:
1) Update of a column in a clustered primary key
2) Update of a column used to calculate which partition the
row belongs to
BUG#11764529 is about case 1) above, BUG#11762751 was about case 2).
The fix for these bugs is to return with an error if multiple-table
update is about to:
a) Update a table through multiple aliases, and
b) Perform an update that may physically more the row
in at least one of these aliases
This avoids
* partial updates as described for MyISAM above,
* provides the same error message that describes the actual problem
for all SEs
* inconsistent behavior where a statement fails or succeeds based on
e.g. the partitioning algorithm of the table.
The problem was that doing ALTER TABLE on a table which had a key
on a TEXT/BLOB column with a prefix longer than the maximum number
of characteres in this column (as per the character set), by mistake,
caused an error (Error 1170 - ER_BLOB_KEY_WITHOUT_LENGTH).
This bug not repeatable in 5.5.
This patch adds a regression test to alter_table.test and
contains no code changes.
("-") IN DATABASE NAMES IN ALTER DATABASE.
mysqldump did not quote database name in 'ALTER DATABASE'
statements in its output. This can further cause a failure
while loading if database name contains a hyphen '-'.
This happened as, while printing the 'ALTER DATABASE'
statements, the database name was not quoted.
Fixed by quoting the database name.
A separate fix for 5.1 (as 5.1 and 5.5 have seriously
differged in the related pieces of the code).
A patch for 5.5 was approved earlier.
Problem: ucs2 was correctly disallowed in "SET NAMES" only,
while mysql_real_connect() and mysql_change_user() still allowed
to use ucs2, which made server crash.
Fix: disallow ucs2 in mysql_real_connect() and mysql_change_user().
@ sql/sql_priv.h
- changing return type for thd_init_client_charset() to bool,
to return errors to the caller
@ sql/sql_var.cc
- using new function
@ sql/sql_connect.cc
- thd_client_charset_init:
in case of unsupported client character set send error and return true;
in case of success return false
- check_connection:
Return error if character set initialization failed
@ sql/sql_parse.cc
- check charset in the very beginnig of the CMD_CHANGE_USER handling code
@ tests/mysql_client_test.c
- adding tests
The loop that was looping over subqueries' references to outer field used a
local boolean variable to tell whether the field was grouped or not. But the
implementor failed to reset the variable after each iteration. Thus a field
that was not directly aggregated appeared to be.
Fixed by resetting the variable upon each new iteration.
Problem: ucs2 was correctly disallowed in "SET NAMES" only,
while mysql_real_connect() and mysql_change_user() still allowed
to use ucs2, which made server crash.
Fix: disallow ucs2 in mysql_real_connect() and mysql_change_user().
@ sql/set_var.cc
Using new function.
@ sql/sql_acl.cc
- Return error if character set initialization failed
- Getting rid of pointer aliasing:
Initialize user_name to NULL, to avoid double free().
@ sql/sql_connect.cc
- in case of unsupported client character set send error and return true
- in case of success return false
@ sql/sql_connect.h
- changing return type for thd_init_client_charset() to bool,
to return errors to the caller
@ sql/sql_parse.h
- introducing a new function, to reuse in all places where we need
to check client character set.
@ tests/mysql_client_test.c
Adding test
MONTHNAME(0) claims that it is about to return NOT NULL
value, whereas it actually returns NULL.
As a result storage_engine variable (which cannot be NULL)
protection was bypassed and NULL value was accepted, causing
server crash.
Fixed MONTHNAME(0) to report valid NULL flag.
Problem:
IF() did not copy collation derivation and repertoire from
an argument if the opposite argument was NULL:
IF(cond, res1, NULL)
IF(cond, NULL, res2)
only CHARSET_INFO pointer was copied.
This resulted in illegal mix of collations error.
Fix:
copy all collation parameters from the non-NULL argument:
CHARSET_INFO pointer, derivation, repertoire.
memory reference
There are two issues present here.
1) There is a possibility that we test a byte beyond the
allocated buffer
2) We compare a byte that might never have been
initalized to see if it's 0.
The first issue is not triggered by existing code, but an
ASSERT has been added to safe-guard against introducing
new code that triggers it.
The second issue is what triggers the Valgrind warnings
reported in the bug report. A buffer is allocated in
class String to hold the value. This buffer is populated
by the character data constituting the string, but is not
zero-terminated in most cases. Testing if it is indeed
zero-terminated means that we check a byte that has never
been explicitly set, thus causing Valgrind to trigger.
Note that issue 2 is not a serious problem. The variable
is read, and if it's not zero, we will set it to zero.
There are no further consequences.
Note that this patch does not fix the underlying problems
with issue 1, as it is deemed too risky to fix at this
point (as noted in the bug report). As discussed in
the report, the c_ptr() method should probably be
replaced, but this requires a thorough analysis of the
~200 calls to the method.
With --mem if fails with
+UNEXPECTED ERROR NUMBER: 1290
In var/log/mysqld.2.err we have:
[ERROR] LOAD DATA INFILE in the slave SQL Thread can only read from --slave-load-tmpdir. Please, report a bug.
[ERROR] Slave SQL: Error 'The MySQL server is running with the --slave-load-tmpdir option so it cannot execute this statement' on query. Default database: 'test'. Query: 'LOAD DATA INFILE '../../tmp/SQL_LOAD-2-1-1.data' INTO TABLE `t1` FIELDS TERMINATED BY '\t' ENCLOSED BY '' ESCAPED BY '\\' LINES TERMINATED BY '\n' (`a`, `b`)', Error_code: 1290
getcwd() in the server yields something like: /dev/shm/var_auto_iv5Q/mysqld.2/data
Assertion `bitmap_is_set_all(&table->s->all_set)' failed in
handler::ha_reset
This followup fixes the compilation warning
'test_bit' may be used uninitialized in this function
introduced by the previous patch.
Assertion `bitmap_is_set_all(&table->s->all_set)' failed in
handler::ha_reset
This assertion could be triggered if two connections simultaneously
executed two bitmap test functions on the same bitmap. For example,
the assertion could be triggered if one connection executed UPDATE
while a second connection executed SELECT on the same table.
Even if bitmap test functions have read-only semantics and have
const bitmaps as parameter, several of them modified the internal
state of the bitmap. With interleaved execution of two such functions
it was possible for one function to modify the state of the same
bitmap that the other function had just modified. This lead to an
inconsistent state and could trigger the assert.
Internally the bitmap uses 32 bit words for storage. Since bitmaps
can contain any number of bits, the last word in the bitmap may
not be fully used. A 32 bit mask is maintained where a bit is set
if the corresponding bit in the last bitmap word is unused.
The problem was that several test functions applied this mask to
the last word. Sometimes the mask was negated and used to zero out
the remainder of the last word and sometimes the mask was used as-is
to fill the remainder of the last word with 1's. This meant that if
a function first used the negated mask and another function then
used the mask as-is (or vice-versa), the first function would then
get the wrong result.
This patch fixes the problem by changing the implementation of
9 bitmap functions that modified the bitmap state even if the
bitmap was declared const. These functions now preserve the
internal state of the bitmap. This makes it possible for
two connections to concurrently execute two of these functions
on the same bitmap without issues.
The patch also removes dead testing code from my_bitmap.c.
These tests have already been moved to unittest/mysys/bitmap-t.c.
Existing test coverage of my_bitmap has been extended.
No MTR test case added as this would require adding several sync
points to the bitmap functions. The patch has been tested with
a non-deterministic test case posted on the bug report.
