* remove duplicate test file
* move all uuidv7 tests into plugin/type_uuid/mysql-test/type_uuid/
* remove mysys/ changes
* auto my_random_bytes() fallback - removes duplicate code from uuid,
and fixes all other users of my_random_bytes() that don't check
the return value (because, perhaps, they don't need crypto-strong
random bytes)
* End of 11.6 -> 11.7 in tests
* clarify the warning text
* UUID_VERSION_MASK()/UUID_VARIANT_MASK() must not depend on the version
* allow 4x more monotonic uuidv7 per millisecond - instead of stretching
1000 microseconds over 12 bits, let's use extra 2 bits as a counter
* rename for compatibility with Percona Server (uuid_v4, uuid_v7)
- Moving the class UUIDv1 into a separate file sql_type_uuid_v1.h
- Adding a new class UUIDv4, similar to UUIDv1
- Changing the way how my_random_bytes() failures are handled.
Instead of raising an error it now raises a note.
Reasoning: if we're in the middle of a multi-million row
transaction and one UUIDv4 generation fails, it's not a good
idea to throw away the entire transaction. Instead, let's
generate bytes using a my_rnd() loop.
- Adding a new test func_uuid_v4.test to demonstrate that the UUIDv4()
returned type is "UUID NOT NULL".
- Adding a new test func_uuidv4_debug.test to emulate my_random_bytes()
failures
- Adding a template Item_func_uuid_vx to share the code
between the implementations of UUID() and UUIDv4().
This task is to ensure we have a clear definition and rules of how to
repair or optimize a table.
The rules are:
- REPAIR should be used with tables that are crashed and are
unreadable (hardware issues with not readable blocks, blocks with
'unexpected data' etc)
- OPTIMIZE table should be used to optimize the storage layout for the
table (recover space for delete rows and optimize the index
structure.
- ALTER TABLE table_name FORCE should be used to rebuild the .frm file
(the table definition) and the table (with the original table row
format). If the table is from and older MariaDB/MySQL release with a
different storage format, it will convert the data to the new
format. ALTER TABLE ... FORCE is used as part of mariadb-upgrade
Here follows some more background:
The 3 ways to repair a table are:
1) ALTER TABLE table_name FORCE" (not other options).
As an alias we allow: "ALTER TABLE table_name ENGINE=original_engine"
2) "REPAIR TABLE" (without FORCE)
3) "OPTIMIZE TABLE"
All of the above commands will optimize row space usage (which means that
space will be needed to hold a temporary copy of the table) and
re-generate all indexes. They will also try to replicate the original
table definition as exact as possible.
For ALTER TABLE and "REPAIR TABLE without FORCE", the following will hold:
If the table is from an older MariaDB version and data conversion is
needed (for example for old type HASH columns, MySQL JSON type or new
TIMESTAMP format) "ALTER TABLE table_name FORCE, algorithm=COPY" will be
used.
The differences between the algorithms are
1) Will use the fastest algorithm the engine supports to do a full repair
of the table (except if data conversions are is needed).
2) Will use the storage engine internal REPAIR facility (MyISAM, Aria).
If the engine does not support REPAIR then
"ALTER TABLE FORCE, ALGORITHM=COPY" will be used.
If there was data incompatibilities (which means that FORCE was used)
then there will be a warning after REPAIR that ALTER TABLE FORCE is
still needed.
The reason for this is that REPAIR may be able to go around data
errors (wrong incompatible data, crashed or unreadable sectors) that
ALTER TABLE cannot do.
3) Will use the storage engine internal OPTIMIZE. If engine does not
support optimize, then "ALTER TABLE FORCE" is used.
The above will ensure that ALTER TABLE FORCE is able to
correct almost any errors in the row or index data. In case of
corrupted blocks then REPAIR possible followed by ALTER TABLE is needed.
This is important as mariadb-upgrade executes ALTER TABLE table_name
FORCE for any table that must be re-created.
Bugs fixed with InnoDB tables when using ALTER TABLE FORCE:
- No error for INNODB_DEFAULT_ROW_FORMAT=COMPACT even if row length
would be too wide. (Independent of innodb_strict_mode).
- Tables using symlinks will be symlinked after any of the above commands
(Independent of the setting of --symbolic-links)
If one specifies an algorithm together with ALTER TABLE FORCE, things
will work as before (except if data conversion is required as then
the COPY algorithm is enforced).
ALTER TABLE .. OPTIMIZE ALL PARTITIONS will work as before.
Other things:
- FORCE argument added to REPAIR to allow one to first run internal
repair to fix damaged blocks and then follow it with ALTER TABLE.
- REPAIR will not update frm_version if ha_check_for_upgrade() finds
that table is still incompatible with current version. In this case the
REPAIR will end with an error.
- REPAIR for storage engines that does not have native repair, like InnoDB,
is now using ALTER TABLE FORCE.
- REPAIR csv-table USE_FRM now works.
- It did not work before as CSV tables had extension list in wrong
order.
- Default error messages length for %M increased from 128 to 256 to not
cut information from REPAIR.
- Documented HA_ADMIN_XX variables related to repair.
- Added HA_ADMIN_NEEDS_DATA_CONVERSION to signal that we have to
do data conversions when converting the table (and thus ALTER TABLE
copy algorithm is needed).
- Fixed typo in error message (caused test changes).
It was wrong to derive Item_func_uuid from Item_func_sys_guid,
because the former is a function returning the UUID data type,
while the latter is a string function returning VARCHAR.
As a result of the wrong hierarchy, Item_func_uuid erroneously derived
Item_str_func::fix_fields(), which contains this code:
/*
In Item_str_func::check_well_formed_result() we may set null_value
flag on the same condition as in test() below.
*/
if (thd->is_strict_mode())
set_maybe_null();
This code is not relevant to UUID() at all.
A simple fix would be to set_maybe_null(false) in
Item_func_uuid::fix_length_and_dec(). However,
it'd fix only exactly this single consequence of the wrong
class hierarchy, and similar bugs could appear again in
the future. Moreover, we're going to add functions UUIDv4()
and UUIDv7() soon (in 11.6). So it's better to fix the class hierarchy
in the right way before adding these new functions.
Fix:
- Adding a new abstract class Item_fbt_func in the template
in sql_type_fixedbin.h
- Deriving Item_typecast_fbt from Item_fbt_func
- Deriving Item_func_uuid from Item_fbt_func
- Adding a new helper class UUIDv1. It derives from UUID, and additionally
initializes the value to "UUID version 1" right in the constructor.
Note, the new coming soon SQL functions UUIDv4() and UUIDv7()
will also have corresponding classes UUIDv4 and UUIDv7.
So now UUID() is a pure "returning UUID" function,
like CAST(expr AS UUID) used to be, without any unintentional
artifacts of functions returning VARCHAR/TEXT.
Cleanup:
- Removing the member Item_func_sys_guid::with_dashes,
as it's not needed any more:
* Item_func_sys_guid now does not have any descendants any more
* Item_func_sys_guid::val_str() itself always displays without dashes
Under terms of MDEV 27490 we'll add support for non-BMP identifiers
and upgrade casefolding information to Unicode version 14.0.0.
In Unicode-14.0.0 conversion to lower and upper cases can increase octet length
of the string, so conversion won't be possible in-place any more.
This patch removes virtual functions performing in-place casefolding:
- my_charset_handler_st::casedn_str()
- my_charset_handler_st::caseup_str()
and fixes the code to use the non-inplace functions instead:
- my_charset_handler_st::casedn()
- my_charset_handler_st::caseup()
Problem:
REPAIR TABLE executed for a pre-MDEV-29959 table (with the old UUID format)
updated the server version in the FRM file without rewriting the data,
so it created a new FRM for old UUIDs. After that MariaDB could not
read UUIDs correctly.
Fix:
- Adding a new virtual method in class Type_handler:
virtual bool type_handler_for_implicit_upgrade() const;
* For the up-to-date data types it returns "this".
* For the data types which need to be implicitly upgraded
during REPAIR TABLE or ALTER TABLE, it returns a pointer
to a new replacement data type handler.
Old VARCHAR and old UUID type handlers override this method.
See more comments below.
- Changing the semantics of the method
Type_handler::Column_definition_implicit_upgrade(Column_definition *c)
to the opposite, so now:
* c->type_handler() references the old data type (to upgrade from)
* "this" references the new data type (to upgrade to).
Before this change Column_definition_implicit_upgrade() was supposed
to be called with the old data type handler (to upgrade from).
Renaming the method to Column_definition_implicit_upgrade_to_this(),
to avoid automatic merges in this method.
Reflecting this change in Create_field::upgrade_data_types().
- Replacing the hard-coded data type tests inside handler::check_old_types()
to a call for the new virtual method
Type_handler::type_handler_for_implicit_upgrade()
- Overriding Type_handler_fbt::type_handler_for_implicit_upgrade()
to call a new method FbtImpl::type_handler_for_implicit_upgrade().
Reasoning:
Type_handler_fbt is a template, so it has access only to "this".
So in case of UUID data types, the type handler for old UUID
knows nothing about the type handler of new UUID inside sql_type_fixedbin.h.
So let's have Type_handler_fbt delegate type_handler_for_implicit_upgrade()
to its Type_collection, which knows both new UUID and old UUID.
- Adding Type_collection_uuid::type_handler_for_implicit_upgrade().
It returns a pointer to the new UUID type handler.
- Overriding Type_handler_var_string::type_handler_for_implicit_upgrade()
to return a pointer to type_handler_varchar (true VARCHAR).
- Cleanup: these two methods:
handler::check_old_types()
handler::ha_check_for_upgrade()
were always called consequently.
So moving the call for check_old_types() inside ha_check_for_upgrade(),
and making check_old_types() private.
- Cleanup: removing the "bool varchar" parameter from fill_alter_inplace_info(),
as its not used any more.
Two new information_schema views are added:
* PERIOD table -- columns TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME,
PERIOD_NAME, START_COLUMN_NAME, END_COLUMN_NAME.
* KEY_PERIOD_USAGE -- works similar to KEY_COLUMN_USAGE, but for periods.
Columns CONSTRAINT_CATALOG, CONSTRAINT_SCHEMA, CONSTRAINT_NAME,
TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, PERIOD_NAME
Two new columns are added to the COLUMNS view:
IS_SYSTEM_TIME_PERIOD_START, IS_SYSTEM_TIME_PERIOD_END - contain YES/NO.
According to the standart draft UUIDv6 and UUIDv7 values
must be compared as opaque raw bytes.
Let's only compare with byte-swapping if both values need
byte swapping.
* modify the test to use different and not monotonous timestamps
* rename methods to be unambiguous (for IDE challenged devs)
* move byte swap checks into helpers
The problem was earlier fixed by a patch for MDEV-27207
68403eeda3
and an additional cleanup patch for MDEV-27207
88dd50b80a
The above patches added MTR tests for INET6.
Now adding UUID specific MTR tests only.
on aarch64 `char` by default is unsigned for performance reasons.
let's adjust checks to work for both signed and unsigned `char`
followup for ef84f8137b
optimizer implicitly assumed that if `a` in `a=b` is not NULL,
then it's safe to convert `a` to the type of `b` and search the
result in the index(b).
which is not always the case, as converting a non-null value
to a different type might produce NULL. And searching for NULL
in the index might find NULL there, so NULL will be equal to NULL,
making `a=b` behave as if it was `a<=>b`
* UUIDs version >= 6 are now stored without byte-swapping
* UUIDs with version >=8 and variant=0 are now considered invalid
* old tables are supported
* old (always byte swapped) and new (swapped for version < 6) UUIDs
can be compared and converted transparently
The main difference in code path between EQ_REF and REF is that for
REF we have to do an extra read_next on the index to check that there
is no more matching rows.
Before this patch we added a preference of EQ_REF by ensuring that REF
would always estimate to find at least 2 rows.
This patch adds the cost of the extra key read_next to REF access and
removes the code that limited REF to at least 2 rows. For some queries
this can have a big effect as the total estimated rows will be halved
for each REF table with 1 rows.
multi_range cost calculations are also changed to take into account
the difference between EQ_REF and REF.
The effect of the patch to the test suite:
- About 80 test case changed
- Almost all changes where for EXPLAIN where estimated rows for REF
where changed from 2 to 1.
- A few test cases using explain extended had a change of 'filtered'.
This is because of the estimated rows are now closer to the
calculated selectivity.
- A very few test had a change of table order.
This is because the change of estimated rows from 2 to 1 or the small
cost change for REF
(main.subselect_sj_jcl6, main.group_by, main.dervied_cond_pushdown,
main.distinct, main.join_nested, main.order_by, main.join_cache)
- No key statistics and the estimated rows are now smaller which cased
estimated filtering to be lower.
(main.subselect_sj_mat)
- The number of total rows are halved.
(main.derived_cond_pushdown)
- Plans with 1 row changed to use RANGE instead of REF.
(main.group_min_max)
- ALL changed to REF
(main.key_diff)
- Key changed from ref + index_only to PRIMARY key for InnoDB, as
OPTIMIZER_ROW_LOOKUP_COST + OPTIMIZER_ROW_NEXT_FIND_COST is smaller than
OPTIMIZER_KEY_LOOKUP_COST + OPTIMIZER_KEY_NEXT_FIND_COST.
(main.join_outer_innodb)
- Cost changes printouts
(main.opt_trace*)
- Result order change
(innodb_gis.rtree)
