table copy".
This patch only adds test case as the bug itself was addressed
by Ramil's fix for bug 50946 "fast index creation still seems
to copy the table".
The task is to
(a) add a comment on indexes and
(b) increase the maximum length of column, table and the new index comments.
The patch committed on behalf of Yoshinori Matsunobu (Yoshinori.Matsunobu@Sun.COM).
corruption and crash results
An index creation statement where the index key
is larger/wider than the column it references
should throw an error.
A statement like:
CREATE TABLE t1 (a CHAR(1), PRIMARY KEY (A(255)))
did not error, but a segmentation fault followed when
an insertion was attempted on the table
The partial key validiation clause has been
restructured to (hopefully) better document which
uses of partial keys are valid.
freezes (win) the server
The check for equality was assuming the field object is always
created. If it's not it was de-referencing a NULL pointer.
Fixed to use the data in the create object instead.
An ALTER TABLE statement which added a column and added
a non-partial index on it failed with:
"ERROR 1089 (HY000): Incorrect sub part key; the used
key part isn't a string, the used length is longer than
the key part, or the storage engine doesn't support unique
sub keys"
In a check introduced to fix an earlier bug (no. 26794),
to allow for indices on spatial type columns, the
test expression was flawed (a logical OR was used instead
of a logical AND), which led to this regression.
The code in question does a sanity check on the key, and
the flawed code mistakenly classified any index created
in the way specified above as a partial index. Since
many data types does not allow partial indices, the
statement would fail.
We set up DATE and TIMESTAMP differently in field-creation than we
did in field-MD creation (for CREATE). Admirably, ALTER TABLE
detected this and didn't damage any data, but it did initiate a
full copy/conversion, which we don't really need to do.
Now we describe Field and Create_field the same for those types.
As a result, ALTER TABLE that only changes meta-data (like a
field's name) no longer forces a data-copy when there needn't
be one.
The problem was that appending values to the end of an existing
ENUM or SET column was being treated as table data modification,
preventing a immediately (fast) table alteration that occurs when
only table metadata is being modified.
The cause was twofold: adding a enumeration or set members to the
end of the list of valid member values was not being considered
a "compatible" table alteration, and for SET columns, the check
was being done upon the max display length and not the underlying
(pack) length of the field.
The solution is to augment the function that checks wether two ENUM
or SET fields are compatible -- by comparing the pack lengths and
performing a limited comparison of the member values.
Problem: mysqld doesn't detect that enum data must be reinserted performing
'ALTER TABLE' in some cases.
Fix: reinsert data altering an enum field if enum values are changed.
The problem was that PACK_KEYS and MAX_ROWS clause in ALTER TABLE did not trigger
table reconstruction.
The fix is to rebuild a table if PACK_KEYS or MAX_ROWS are specified.
The problem was that when comparing tables for a possible
fast alter table, the comparison was being performed using
the parsed information and not the final definition.
The solution is to use the possible final table layout to
compare if a fast alter is possible or not.
added get_field_default_value() function which obtains default value from the field
(used in store_create_info() & get_schema_column_record() functions)
INSERT/DELETE/UPDATE followed by ALTER TABLE within LOCK TABLES
may cause table corruption on Windows.
That happens because ALTER TABLE writes outdated shared state
info into index file.
Fixed by removing obsolete workaround.
Affects MyISAM tables on Windows only.
To avoid unnecessary work the mysql_alter_table function takes the
list of table fields and applies all changes to it (drops/moves/renames/etc).
Then this function compares the new list and the old one. If the changes
require only .frm to be modified then the actual data isn't copied. To detect
changes all columns attributes but names are compared. When a column has been
moved and has replaced another column with the same attributes except name
the mysql_alter_table function wrongly decides that two fields has been just
renamed. As a result the data from the moved column and from all columns
after it is not copied.
Now the mysql_alter_table function forces table data copying by setting
the need_copy_table flag when it finds a moved column. The flag is set at
the stage when the modified fields are created.
mode.
When a new DATE/DATETIME field without default value is being added by the
ALTER TABLE the '0000-00-00' value is used as the default one. But it wasn't
checked whether such value was allowed by the set sql mode. Due to this
'0000-00-00' values was allowed for DATE/DATETIME fields even in the
NO_ZERO_DATE mode.
Now the mysql_alter_table() function checks whether the '0000-00-00' value
is allowed for DATE/DATETIME fields by the set sql mode.
The new error_if_not_empty flag is used in the mysql_alter_table() function
to indicate that it should abort if the table being altered isn't empty.
The new new_datetime_field field is used in the mysql_alter_table() function
for error throwing purposes.
The new error_if_not_empty parameter is added to the copy_data_between_tables()
function to indicate the it should return error if the source table isn't empty.
and invalidation in the most general case (non-temporary table and
not simple RENAME or ENABLE/DISABLE KEYS or partitioning command).
See comment for sql/sql_table.cc for more information.
These changes are prerequisite for 5.1 version of fix for bug #23667
"CREATE TABLE LIKE is not isolated from alteration by other connections"
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.
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.
table
ROW_FORMAT option is lost during CREATE/DROP INDEX.
This fix forces CREATE/DROP INDEX to retain ROW_FORMAT by instructing
mysql_alter_table() that ROW_FORMAT is not used during creating/dropping
indexes.
with other alterations causes lost tables
Using RENAME clause combined with other clauses of ALTER TABLE led to
data loss (the data was there but not accessible). This could happen if the
changes do not change the table much. Adding and droppping of fields and
indices was safe. Renaming a column with MODIFY or CHANGE was unsafe operation,
if the actual column didn't change (changing from int to int, which is a noop)
Depending on the storage engine (SE) the behavior is different:
1)MyISAM/MEMORY - the ALTER TABLE statement completes
without any error but next SELECT against the new table fails.
2)InnoDB (and every other transactional table) - The ALTER TABLE statement
fails. There are the the following files in the db dir -
`new_table_name.frm` and a temporary table's frm. If the SE is file
based, then the data and index files will be present but with the old
names. What happens is that for InnoDB the table is not renamed in the
internal DDIC.
Fixed by adding additional call to mysql_rename_table() method, which should
not include FRM file rename, because it has been already done during file
names juggling.
