- During insertion of clustered inde, InnoDB does the check for
foreign key constraints. It rebuild the tuple based on foreign
column names when there is no foreign index. While rebuilding,
InnoDB should ignore the dropped columns.
dict_foreign_qualify_index(): Reject corrupted or garbage indexes.
For index stubs that are created on virtual columns, no
dict_field_t::col would be assign. Instead, the entire table
definition would be reloaded on a successful operation.
Problem:
=======
InnoDB drops the column which has foreign key relations on it. So it
tries to load the foreign key during rename process of copy algorithm
even though the foreign_key_check is disabled.
Solution:
========
During alter copy algorithm, InnoDB ignores the error while loading
the foreign key constraint if foreign key check is disabled. It
should throw the warning about failure of the foreign key constraint
when foreign key check is disabled.
CHECK constraint is checked by check_expression() which walks its
items and gets into Item_field::check_vcol_func_processor() to check
for conformity with foreign key list.
WITHOUT OVERLAPS is checked for same conformity in
mysql_prepare_create_table().
Long uniques are already impossible with InnoDB foreign keys. See
ER_CANT_CREATE_TABLE in test case.
2 accompanying bugs fixed (test main.constraints failed):
1. check->name.str lived on SP execute mem_root while "check" obj
itself lives on SP main mem_root. On second SP execute check->name.str
had garbage data. Fixed by allocating from thd->stmt_arena->mem_root
which is SP main mem_root.
2. CHECK_CONSTRAINT_IF_NOT_EXISTS value was mixed with
VCOL_FIELD_REF. VCOL_FIELD_REF is assigned in check_expression() and
then detected as CHECK_CONSTRAINT_IF_NOT_EXISTS in
handle_if_exists_options().
Existing cases for MDEV-16932 in main.constraints cover both fixes.
FOREIGN_KEY_CHECKS is disabled
- Referenced index can be null While renaming the referenced column name.
In that case, rename the referenced column name in dict_foreign_t and
find the equivalent referenced index.
In main.index_merge_myisam we remove the test that was added in
commit a2d24def8c because
it duplicates the test case that was added in
commit 5af12e4635.
FOREIGN_KEY_CHECKS is disabled
- dict_foreign_find_index() can return NULL if InnoDB already dropped
the foreign index when FOREIGN_KEY_CHECKS is disabled.
Add support of referential constraints directly in column defininions:
create table t1 (id1 int primary key);
create table t2 (id2 int references t1(id1));
Referenced field name can be omitted if equal to foreign field name:
create table t1 (id int primary key);
create table t2 (id int references t1);
Until 10.5 this syntax was understood by the parser but was silently
ignored.
In case of generated columns this syntax is disabled at parser level
by ER_PARSE_ERROR. Note that separate FOREIGN KEY clause for generated
columns is disabled at storage engine level.
This allows one to run the test suite even if any of the following
options are changed:
- character-set-server
- collation-server
- join-cache-level
- log-basename
- max-allowed-packet
- optimizer-switch
- query-cache-size and query-cache-type
- skip-name-resolve
- table-definition-cache
- table-open-cache
- Some innodb options
etc
Changes:
- Don't print out the value of system variables as one can't depend on
them to being constants.
- Don't set global variables to 'default' as the default may not
be the same as the test was started with if there was an additional
option file. Instead save original value and reset it at end of test.
- Test that depends on the latin1 character set should include
default_charset.inc or set the character set to latin1
- Test that depends on the original optimizer switch, should include
default_optimizer_switch.inc
- Test that depends on the value of a specific system variable should
set it in the test (like optimizer_use_condition_selectivity)
- Split subselect3.test into subselect3.test and subselect3.inc to
make it easier to set and reset system variables.
- Added .opt files for test that required specfic options that could
be changed by external configuration files.
- Fixed result files in rockdsb & tokudb that had not been updated for
a while.
dict_create_foreign_constraints_low(): Tolerate the keywords
IGNORE and ONLINE between the keywords ALTER and TABLE.
We should really remove the hacky FOREIGN KEY constraint parser
from InnoDB.
dict_create_foreign_constraints_low(): Clean up the way in
which the error messages are initialized, and ensure that
the table name is always initialized.
The code path where the table was not being rebuilt during ALTER TABLE
was not covered by the test. Add coverage, and remove the debug assertion
that could fail in this case.
ha_innobase::commit_inplace_alter_table(): Do not crash if
innobase_update_foreign_cache() returns an error. It can return
an error on ALTER TABLE if an inconsistent FOREIGN KEY constraint
was created earlier when SET foreign_key_checks=0 was in effect.
Instead, report a warning to the client that constraints cannot
be loaded.
In RENAME TABLE, when an error occurs while renaming FOREIGN KEY
constraint, that error would be overwritten when renaming the
InnoDB internal tables related to FULLTEXT INDEX.
row_rename_table_for_mysql(): Do not attempt to rename the internal
tables if an error already occurred.
This problem was originally reported as Oracle Bug#27545888.
row_ins_check_foreign_constraint(): Do not overwrite hard errors
with the soft error DB_LOCK_WAIT. This prevents an infinite
wait loop when DB_INTERRUPTED was returned. For DB_LOCK_WAIT,
row_insert_for_mysql() would keep invoking row_ins_step() and the
transaction would remain active until the server shutdown is initiated.
table_already_fk_prelocked() was looking for a table in the wrong
list (not the complete list of prelocked tables, but only in its tail,
starting from the current table - which is always empty for the last
added table), so for circular FKs it kept adding same tables to the list
indefinitely.
Backport of d6d7e169fb
