repair it
Multi-table delete that is optimized with QUICK_RANGE reports table
corruption.
DELETE statement must not use KEYREAD optimization, and sets
table->no_keyread to 1. This was ignored in QUICK_RANGE optimization.
With this fix QUICK_RANGE optimization honors table->no_keyread
value and does not enable KEYREAD when it is requested.
When only one row was present, the subtraction of nearly the same number
resulted in catastropic cancellation, introducing an error in the
VARIANCE calculation near 1e-15. That was sqrt()ed to get STDDEV, the
error was escallated to near 1e-8.
The simple fix of testing for a row count of 1 and forcing that to yield
0.0 is insufficient, as two rows of the same value should also have a
variance of 0.0, yet the error would be about the same.
So, this patch changes the formula that computes the VARIANCE to be one
that is not subject to catastrophic cancellation.
In addition, it now uses only (faster-than-decimal) floating point numbers
to calculate, and renders that to other types on demand.
An update that used a join of a table to itself and modified the
table on one side of the join reported the table as crashed or
updated wrong rows.
Fixed by creating temporary table for self-joined multi update statement.
Handling of large signed/unsigned values was not consistent, so some string functions could return bogus results.
The current fix is to simply patch up the val_str() methods for those string items.
It would be good clean this code up in general, to make similar problems much harder to make. This is left as an exercise for the reader.
If SELECT-part of CREATE VIEW statement contains '\Z',
it is not handled correctly.
The problem was in String::print().
Symbol with code 032 (26) is replaced with '\z',
which is not supported by the lexer.
The fix is to replace the symbol with '\Z'.
Applied innodb-5.0-ss1040 and innodb-5.0-ss1099 snapshots.
Bugs fixed:
- Bug #21468: InnoDB crash during recovery with corrupted data pages: XA bug?
- Bug #24299: Identifiers in foreign keys cannot contain U+0160, U+0360, ..., U+FF60
- Bug #24386: Performance degradation caused by instrumentation in mutex_struct
- Bug #24712: SHOW TABLE STATUS for file-per-table showing incorrect time fields
Having broken .frm, particulary number of field names does
not match number of fields, causes server crash.
Refuse to open a table if number of field names in a table
is not equal to number of fields in a table.
No test case, since it requires broken .frm file.
the UDF
When deleting a user defined function MySQL must remove it from both the
in-memory hash table and the mysql.proc system table.
Finding (and removal therefore) from the internal hash table is case
insensitive (or whatever the default charset is), whereas finding and
removal from the system table is case sensitive.
As a result if you supply a function name that is not in the same character
case to DROP FUNCTION the server will remove the function only from the
in-memory hash table and will keep the row in mysql.proc system table.
This will cause inconsistency between the two structures (that is fixed
only by restarting the server).
Fixed by using the name in the precise case (from the in-memory hash table)
to delete the row in the mysql.proc system table.
Problem:
When creating a temporary field for a temporary table in create_tmp_field_from_field(), a resulting field is created as an exact copy of an original one (in Field::new_field()). However, Field_enum and Field_set contain a pointer (typelib) to memory allocated in the parent table's MEM_ROOT, which under some circumstances may be deallocated later by the time a temporary table is used.
Solution:
Override the new_field() method for Field_enum and Field_set and create a separate copy of the typelib structure in there.
Blocked evaluation of constant objects of the classes
Item_func_is_null and Item_is_not_null_test at the
prepare phase in the cases when the objects used subqueries.
Removed an assertion that was not valid for the cases where the query
in a prepared statement contained a single-row non-correlated
subquery that was used as an argument of the IS NULL predicate.
