This bug was intruduced by the fix for bug#17212 (in 4.1). It is not
ok to call test_if_skip_sort_order since this function will
alter the execution plan. By contract it is not ok to call
test_if_skip_sort_order in this context.
This bug appears only in the case when the optimizer has chosen
an index for accessing a particular table but finds a covering
index that enables it to skip ORDER BY. This happens in
test_if_skip_sort_order.
It was syntactically correct to define
spatial keys over parts of columns (e.g.
ALTER TABLE t1 ADD x GEOMETRY NOT NULL,
ADD SPATIAL KEY (x(32))).
This may lead to undefined results and/or
interpretation.
Fixed by not allowing partial column
specification in a SPATIAL index definition.
Different set of conditions is used to verify
the validity of index definitions over a GEOMETRY
column in ALTER TABLE and CREATE TABLE.
The difference was on how sub-keys notion validity
is checked.
Fixed by extending the CREATE TABLE condition to
support the cases allowed in ALTER TABLE.
Made the SHOW CREATE TABLE not to display spatial
indexes using the sub-key notion.
The previous two patches for this bug worked together so that
no permanent table was memory mapped. The first patch tried to
avoid mapping while a table is in use. It allowed mapping only
if there was exactly one lock on the table, assuming that the
calling thread owned it. During mi_open(), a different call to
memory mapping was coded, which did not have this limitation.
The second patch tried to remove the code duplication and just
called mi_extra() from mi_open() an thus inherited the limitation.
But on open, a thread does not have a lock on the table...
A possible solution would be to check for zero or one lock.
But since I learned that it is safe to memory map a file while
normal file I/O is done on it, I removed the restriction altogether
and allow to memory map while a table is in use.
No test case. I do not see a chance to verify with the test suite
which kind of I/O is used on a table.
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.
Different set of conditions is used to verify
the validity of index definitions over a GEOMETRY
column in ALTER TABLE and CREATE TABLE.
The difference was on how sub-keys notion validity
is checked.
Fixed by extending the CREATE TABLE condition to
support the cases allowed in ALTER TABLE.
Made the SHOW CREATE TABLE not to display spatial
indexes using the sub-key notion.
when the column is to be read from a derived table column which
was specified as a concatenation of string literals.
The bug happened because the Item_string::append did not adjust the
value of Item_string::max_length. As a result of it the temporary
table column defined to store the concatenation of literals was
not wide enough to hold the whole value.
after single-row table substitution could lead to a wrong result set.
The bug happened because the function Item_field::replace_equal_field
erroniously assumed that any field included in a multiple equality
with a constant has been already substituted for this constant.
This not true for fields becoming constant after row substitutions
for constant tables.
sql_yacc.yy:
WL3527: updated the diff to use correct parser words
table.cc:
WL3527: exteneded the fix for bug #20604 to fit the new variables
sql_select.cc:
WL3527: renamed used_keys to covering_keys
