command and reported to a client.
The fact that a timestamp field will be set to NO on UPDATE wasn't shown
by the SHOW COMMAND and reported to a client through connectors. This led to
problems in the ODBC connector and might lead to a user confusion.
A new filed flag called ON_UPDATE_NOW_FLAG is added.
Constructors of the Field_timestamp set it when a field should be set to NOW
on UPDATE.
The get_schema_column_record function now reports whether a timestamp field
will be set to NOW on UPDATE.
After adding an index the <VARBINARY> IN (SELECT <BINARY> ...)
clause returned a wrong result: the VARBINARY value was illegally padded
with zero bytes to the length of the BINARY column for the index search.
(<VARBINARY>, ...) IN (SELECT <BINARY>, ... ) clauses are affected too.
UNIQUE (eq-ref) lookups result in table being considered as a "constant" table.
Queries that consist of only constant tables are processed in do_select() in a
special way that doesn't invoke evaluate_join_record(), and therefore doesn't
increase the counters join->examined_rows and join->thd->row_count.
The patch increases these counters in this special case.
NOTICE:
This behavior seems to contradict what the documentation says in Sect. 5.11.4:
"Queries handled by the query cache are not added to the slow query log, nor
are queries that would not benefit from the presence of an index because the
table has zero rows or one row."
No test case in 5.0 as issue shows only in slow query log, and other counters
can give subtly different values (with regard to counting in create_sort_index(),
synthetic rows in ROLLUP, etc.).
BETWEEN was more lenient with regard to what it accepted as a DATE/DATETIME
in comparisons than greater-than and less-than were. ChangeSet makes < >
comparisons similarly robust with regard to trailing garbage (" GMT-1")
and "missing" leading zeros. Now all three comparators behave similarly
in that they throw a warning for "junk" at the end of the data, but then
proceed anyway if possible. Before < > fell back on a string- (rather than
date-) comparison when a warning-condition was raised in the string-to-date
conversion. Now the fallback only happens on actual errors, while warning-
conditions still result in a warning being to delivered to the client.
The bug is a regression introduced by the fix for bug30596. The problem
was that in cases when groups in GROUP BY correspond to only one row,
and there is ORDER BY, the GROUP BY was removed and the ORDER BY
rewritten to ORDER BY <group_by_columns> without checking if the
columns in GROUP BY and ORDER BY are compatible. This led to
incorrect ordering of the result set as it was sorted using the
GROUP BY columns. Additionaly, the code discarded ASC/DESC modifiers
from ORDER BY even if its columns were compatible with the GROUP BY
ones.
This patch fixes the regression by checking if ORDER BY columns form a
prefix of the GROUP BY ones, and rewriting ORDER BY only in that case,
preserving the ASC/DESC modifiers. That check is sufficient, since the
GROUP BY columns contain a unique index.
causes out of memory errors
The code in mysql_create_function() and mysql_drop_function() assumed
that the only reason for UDFs being uninitialized at that point is an
out-of-memory error during initialization. However, another possible
reason for that is the --skip-grant-tables option in which case UDF
initialization is skipped and UDFs are unavailable.
The solution is to check whether mysqld is running with
--skip-grant-tables and issue a proper error in such a case.
HOUR(), MINUTE(), ... returned spurious results when used on a DATE-cast.
This happened because DATE-cast object did not overload get_time() method
in superclass Item. The default method was inappropriate here and
misinterpreted the data.
Patch adds missing method; get_time() on DATE-casts now returns SQL-NULL
on NULL input, 0 otherwise. This coincides with the way DATE-columns
behave.
variable in where clause.
Problem: the new_item() method of Item_uint used an incorrect
constructor. "new Item_uint(name, max_length)" calls
Item_uint::Item_uint(const char *str_arg, uint length) which assumes the
first argument to be the string representation of the value, not the
item's name. This could result in either a server crash or incorrect
results depending on usage scenarios.
Fixed by using the correct constructor in new_item():
Item_uint::Item_uint(const char *str_arg, longlong i, uint length).
Calculating the estimated number of records for a range scan may take a
significant time, and it was impossible for a user to interrupt that
process by killing the connection or the query.
Fixed by checking the thread's 'killed' status in check_quick_keys() and
interrupting the calculation process if it is set to a non-zero value.
tables or more
The problem was that the optimizer used the join buffer in cases when
the result set is ordered by filesort. This resulted in the ORDER BY
clause being ignored, and the records being returned in the order
determined by the order of matching records in the last table in join.
Fixed by relaxing the condition in make_join_readinfo() to take
filesort-ordered result sets into account, not only index-ordered ones.
