- Adding automatic conversion operator from LEX_STRING to LEX_CSTRING
Now a LEX_STRING can be passed directly to any function expecting
a LEX_CSTRING parameter passed by value or by reference.
- Removing a number of duplicate methods accepting LEX_STRING.
Now the code used the LEX_CSTRING version.
Also fixing: MDEV-31719 Wrong result of: WHERE inet6_column IN ('','::1')
Problem:
When converting an Item value from string to INET6 it's possible
that the Item value itself is a not-NULL string value,
while the following result of the string-to-INET6 conversion returns NULL.
Methods cmp_item_xxx::set(), cmp_item_xxx::store_value_by_template(),
in_inet6::set() did not take this scenario into account and
tested source_item->null_value, which does not indicate if the conversion
failed.
Changing the return data type of the mentioned methods from "void" to "bool".
"true" means that:
- either the source Item was NULL
- or the source Item was not NULL, but the data type coversion to
the destination data type (INET6 in this issue) returned NULL.
"false" means that the Item was not NULL and the data type conversion
to the destination data type worked without error.
This patches fixes the INET6 data type.
After merging to 10.9, this patch should also fix same problems in UUID.
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
Adding tests demonstrating that columns:
- mysql.innodb_table_stats.last_update
- mysql.innodb_index_stats.last_update
contain sane values close to NOW() rathar than a garbage.
Tests cover these three underlying TIMESTAMP data formats:
- MariaDB Field_timestamp0 - UINT4 based
Like in a MariaDB native installation running with mysql56_temporal_format=0
- MariaDB Field_timestampf - BINARY(4) based, with UNSIGNED_FLAG
Like in a MariaDB native installation running with mysql56_temporal_format=1
- MySQL-alike Field_timestampf - BINARY(4) based, without UNSIGNED_FLAG
Like with a MariaDB server running over a MySQL-5.6 directory
(e.g. during a migragion).
Problem:
Field_timestampf implementations differ in MySQL and MariaDB:
- MariaDB sets the UNSIGNED_FLAG in Field::flags
- MySQL does not
The reference table structures
(defined in table_stats_schema and index_stats_schema)
expected the last_update column to have the DATA_UNSIGNED flag,
because MariaDB's Field_timestampf has the UNSIGNED_FLAG.
It worked fine on pure MariaDB installations.
However, if a MariaDB server starts over a MySQL-5.7 data directory during
a migration, the last_update column does not have DATA_UNSIGNED flag,
because MySQL's Field_timestampf does not have the UNSIGNED_FLAG.
This made InnoDB (after the migration from MySQL) complain into the server
error log about the unexpected data type.
The actual fix is done in storage/innobase/dict/dict0stats.cc:
It removes DATA_UNSIGNED from the prtype_mask member of the reference columns,
so now it does not require the underlying columns to have this flag.
The rest of the fix is needed for MTR tests.
The new data type plugin TYPE_MYSQL_TIMESTAMP implements a slightly modified
version of Field_timestampf, which removes the unsigned flag, so
it works like MySQL's Field_timestampf.
The MTR test ALTERs the data type of the columns
table_stats_schema.last_update and index_stats_schema.last_update
from TIMESTAMP to TYPE_MYSQL_TIMESTAMP, then makes InnoDB
verify the structure of the two statistics tables by creating
and populating an InnoDB table t1.
Without the fix made storage/innobase/dict/dict0stats.cc,
MTR complains about unexpected warnings in the server error log:
[ERROR] InnoDB: Column last_update in table mysql.innodb_table_stats is ...
[ERROR] InnoDB: Column last_update in table mysql.innodb_index_stats is ...
With the fix made storage/innobase/dict/dict0stats.cc these warnings
go away.
