A bug in the restore_prev_nj_state function allowed interleaving
inner tables of outer join operations with outer tables. With the
current implementation of the nested loops algorithm it could lead
to wrong result sets for queries with nested outer joins.
Another bug in this procedure effectively blocked evaluation of some
valid execution plans for queries with nested outer joins.
with the space character.
When the my_strnncollsp_simple function compares two strings and one is a prefix
of another then this function compares characters in the rest of longer key
with the space character to find whether the longer key is greater or less.
But the sort order of the collation isn't used in this comparison. This may
lead to a wrong comparison result, wrongly created index or wrong order of the
result set of a query with the ORDER BY clause.
Now the my_strnncollsp_simple function uses collation sort order to compare
the characters in the rest of longer key with the space character.
An assertion abort could occur for some grouping queries that employed
decimal user variables with assignments to them.
The problem appeared the constructors of the class Field_new_decimal
because the function my_decimal_length_to_precision did not guarantee
returning decimal precision not greater than DECIMAL_MAX_PRECISION.
The cast operation ignored the cases when the precision and/or the scale exceeded
the limits, 65 and 30 respectively. No errors were reported in these cases.
For some queries this may lead to an assertion abort.
Fixed by throwing errors for such cases.
The SELECT INTO OUTFILE FIELDS ENCLOSED BY digit or minus sign,
followed by the same LOAD DATA INFILE statement, used wrond encoding
of non-string fields contained the enclosed character in their text
representation.
Example:
SELECT 15, 9 INTO OUTFILE 'text' FIELDS ENCLOSED BY '5';
Old encoded result in the text file:
5155 595
^ was decoded as the 1st enclosing character of the 2nd field;
^ was skipped as garbage;
^ ^ was decoded as a pair of englosing characters of the 1st field;
^ was decoded as traling space of the first field;
^^ was decoded as a doubled enclosed character.
New encoded result in the text file:
51\55 595
^ ^ pair of enclosing characters of the 1st field;
^^ escaped enclosed character.
AsText() needs to know the maximum number of
characters a IEEE double precision value can
occupy to make sure there's enough buffer space.
The number was too small to hold all possible
values and this caused buffer overruns.
Fixed by correcting the calculation of the
maximum digits in a string representation of an
IEEE double precision value as printed by
String::qs_append(double).
This bug may manifest itself for select queries over a multi-table view
that includes an ORDER BY clause in its definition. If the select list of
the query contains references to the same view column with different
aliases the names of the columns in the result output will be nevertheless
the same, coinciding with one of the alias.
The bug happened because the method Item_ref::get_tmp_table_item that
was inherited by the class Item_direct_view_ref ignored the fact that
the name of the view column reference must be inherited by the fields
of the temporary table that was created in order to get the result rows
sorted.
The `SELECT 'r' INTO OUTFILE ... FIELDS ENCLOSED BY 'r' ' statement
encoded the 'r' string to a 4 byte string of value x'725c7272'
(sequence of 4 characters: r\rr).
The LOAD DATA statement decoded this string to a 1 byte string of
value x'0d' (ASCII Carriage Return character) instead of the original
'r' character.
The same error also happened with the FIELDS ENCLOSED BY clause
followed by special characters: 'n', 't', 'r', 'b', '0', 'Z' and 'N'.
NOTE 1: This is a result of the undocumented feature: the LOAD DATA INFILE
recognises 2-byte input sequences like \n, \t, \r and \Z in addition
to documented 2-byte sequences: \0 and \N. This feature should be
documented (here backspace character is a default ESCAPED BY character,
in the real-life example it may be any ESCAPED BY character).
NOTE 2, changed behaviour:
Now the `SELECT INTO OUTFILE' statement with the `FIELDS ENCLOSED BY'
clause followed by one of: 'n', 't', 'r', 'b', '0', 'Z' or 'N' characters
encodes this special character itself by doubling it ('r' --> 'rr'),
not by prepending it with an escape character.
This bug may manifest itself not only with the queries for which
the index-merge access method is chosen. It also may display
itself for queries with DISTINCT.
The bug was in how the Unique::get method used the merge_buffers
function. To compare elements in the the queue employed by
merge_buffers() it must use the buffpek_compare function rather
than the function for binary comparison.
When a UNION statement forced conversion of an UTF8
charset value to a binary charset value, the byte
length of the result values was truncated to the
CHAR_LENGTH of the original UTF8 value.
spaces.
When the my_strnncollsp_simple function compares two strings and one is a prefix
of another then this function compares characters in the rest of longer key
with the space character to find whether the longer key is greater or less.
But the sort order of the collation isn't used in this comparison. This may
lead to a wrong comparison result, wrongly created index or wrong order of the
result set of a query with the ORDER BY clause.
Now the my_strnncollsp_simple function uses collation sort order to compare
the characters in the rest of longer key with the space character.
query / no aggregate of subquery
The optimizer counts the aggregate functions that
appear as top level expressions (in all_fields) in
the current subquery. Later it makes a list of these
that it uses to actually execute the aggregates in
end_send_group().
That count is used in several places as a flag whether
there are aggregates functions.
While collecting the above info it must not consider
aggregates that are not aggregated in the current
context. It must treat them as normal expressions
instead. Not doing that leads to incorrect data about
the query, e.g. running a query that actually has no
aggregate functions as if it has some (and hence is
expected to return only one row).
Fixed by ignoring the aggregates that are not aggregated
in the current context.
One other smaller omission discovered and fixed in the
process : the place of aggregation was not calculated for
user defined functions. Fixed by calling
Item_sum::init_sum_func_check() and
Item_sum::check_sum_func() as it's done for the rest of
the aggregate functions.
"Federared Transactions Failure"
Bug occurs when the user performs an operation which inserts more than
one row into the federated table and the federated table references a
remote table stored within a transactional storage engine. When the
insert operation for any one row in the statement fails due to
constraint violation, the federated engine is unable to perform
statement rollback and so the remote table contains a partial commit.
The user would expect a statement to perform the same so a statement
rollback is expected.
This bug was fixed by implementing bulk-insert handling into the
federated storage engine. This will relieve the bug for most common
situations by enabling the generation of a multi-row insert into the
remote table and thus permitting the remote table to perform
statement rollback when neccessary.
The multi-row insert is limited to the maximum packet size between
servers and should the size overflow, more than one insert statement
will be sent and this bug will reappear. Multi-row insert is disabled
when an "INSERT...ON DUPLICATE KEY UPDATE" is being performed.
The bulk-insert handling will offer a significant performance boost
when inserting a large number of small rows.
This patch builds on Bug29019 and Bug25511
"Federated INSERT failures"
Federated does not correctly handle "INSERT...ON DUPLICATE KEY UPDATE"
However, implementing such support is not reasonably possible without
increasing complexity of the storage engine: checking that constraints
on remote server match local server and parsing error messages.
This patch causes 'ON DUPLICATE KEY' to fail with ER_DUP_KEY message
if a conflict occurs and not to fail silently.
SHOW CREATE TABLE or SELECT FROM I_S.
Actually, the bug discovers two problems:
- the original query is not preserved properly. This is the problem
of BUG#16291;
- the resultset of SHOW CREATE TABLE statement is binary.
This patch fixes the second problem for the 5.0.
Both problems will be fixed in 5.1.
Problem: like_range() returned wrong ranges for contractions (like 'ch' in Czech').
Fix: adding a special code to handle tricky cases:
- contraction head followed by a wild character
- full contraction
- contraction part followed by another contraction part,
but they are not a contraction together.
"REPLACE/INSERT IGNORE/UPDATE IGNORE doesn't work"
Federated does not record neccessary HA_EXTRA flags in order to
support REPLACE/INSERT IGNORE/UPDATE IGNORE.
Implement ::extra() to capture flags neccessary for functionality.
New function append_ident() to better escape identifiers consistantly.
Fulltext index may get corrupt by certain gbk characters.
The problem was that when skipping leading non-true-word-characters,
we assumed that these characters are always 1 byte long. This is not
the case with gbk character set, since non-true-word-characters may
be 2 bytes long.
Affects 5.0 only.
Thanks to Martin Friebe for finding and submitting a fix for this bug!
A table with maximum number of key segments and maximum length key name
would have a corrupted .frm file, due to an incorrect calculation of the
complete key length. Now the key length is computed correctly (I hope) :-)
MyISAM would reject a table with the maximum number of keys and the maximum
number of key segments in all keys. It would allow one less than this total
maximum. Now MyISAM accepts a table defined with the maximum. (This is a
very minor issue.)
CHECK TABLE against ARCHIVE table may falsely report table corruption,
or cause server crash.
Fixed by using proper buffer for CHECK TABLE.
Affects both 5.0 and 5.1.
