A 0xHHHH / b'..' literal keeps its hex_hybrid type through COALESCE/IF/CASE/...,
but was evaluated, sized and stored as a string, so it behaved differently from
a bare literal (10+COALESCE(0x31) gave 11, not 59).
Type_handler_hex_hybrid now implements the numeric side to match the bare
literal: val_int/val_real/val_decimal read bytes as a hybrid, Item_decimal_precision
returns the integer precision, Item_save_in_field stores like the bare literal.
The traditional type merge keeps the hybrid through a typeless NULL (as for BIT),
and Item_hybrid_func_fix_attributes attributes it binary/unsigned.
When setup_copy_fields() needs to copy a non-aggregate function value,
it doesn't construct an Item_copy directly. Instead, it calls
Type_handler::create_item_copy, which is a kind of factory. The base
Type_handler::create_item_copy returns Item_copy_string. Some type
handlers override it, like timestamp and fixed binary. However, the
numeric type handlers (e.g., float, double, int, decimal) did not, so
they fell through to that base and got Item_copy_string.
A SELECT that aggregates will copy each non aggregate function value
into a temporary table through an Item_copy object, whose concrete
type is chosen by the create_item_copy method on the value's type
handler. For numeric types that method returned Item_copy_string,
which stores the value as text. A FLOAT keeps only FLT_DIG
significant digits as text, too few to reproduce its 24 bit mantissa,
so the copied value differed from the original. With one row per
group, CAST(c1 AS FLOAT) - MIN(CAST(c1 AS FLOAT)) returned a large
number instead of zero.
Add Item_copy_real with Item_copy_float and Item_copy_double variants
that keep the value as a double, the same way Item_cache_real does, and
let the float and double type handlers create them. This mirrors the
existing copy items for timestamp and fixed binary types.
Type_handler_int_result::Item_decimal_precision assumes that
max_length includes space for a sign, but Item_int literals don't
include such a space. When aggregate_attributes_int propagates these
into functions via a Item_type_holder, the formula computes
precision-1 (or 0 for 1-digit cases), producing the incorrect
calculation with AVG.
This fix changes aggregate_attributes_int to follow the convention the
Type_handler expects, that max_length = max digit-count + (signed ? 1
: 0). This matches the TODO comment that begins with "TODO: rewrite
aggregate_attributes_int()... " which suggested this idea.
Year::year_precision(): Make static, so that VYear::VYear
and VYear_op::VYear_op() will avoid invoking this function with
an unnecessary "this" pointer to an uninitialized object.
Item_singerow_subselect::fix_length_and_dec() incorrectly calculated
its Item::max_length when the underlying expression was Item_int.
The reason of the problem:
Item_int has an optimized max_length to make CONCAT(1) create a VARCHAR(1)
column rather than a VARCHAR(2) column. Its max_length does not include one
extra character for the sign in case the value is positive but the value
is not marked as Item::unsigned==true.
So copying max_length from the underlying Item_int (with value==9)
in cases like this:
SELECT CONCAT((SELECT 9 FROM t0));
was not correct.
Implementing a new virtual method
Type_handler::Item_type_std_attributes_generic(const Item *item)
- The default implementation just copies attributes from "item" as is.
- In case of Type_handler_int_result it evaluates max_length
using item->decimal_precision() rather than item->max_length.
This works correctly for both "optimized" items like Item_int and
non-"optimized" Items whose max_length includes +1 for the sign
in case of signed expressions.
all params are initialized to use Type_handler_null.
NULL params do not have a value to read from the packet buffer,
so their Item_param_set_param_func() should do nothing.
Type_handler_null inherits from Type_handler_string_result,
that is, Type_handler_null *must* override parent's
Item_param_set_param_func().
- Removed duplicate words, like "the the" and "to to"
- Removed duplicate lines (one double sort line found in mysql.cc)
- Fixed some typos found while searching for duplicate words.
Command used to find duplicate words:
egrep -rI "\s([a-zA-Z]+)\s+\1\s" | grep -v param
Thanks to Artjoms Rimdjonoks for the command and pointing out the
spelling errors.
In commit fa7d4abf16
when the 16-bit type alias decimal_digits_t was introduced,
some incompatible use of the 32-bit uint data type was overlooked.
Only for converting Item_result_field::max_length (uint), we will use
explicit conversion.
Search conditions were evaluated using val_int(), which was wrong.
Fixing the code to use val_bool() instead.
Details:
- Adding a new item_base_t::IS_COND flag which marks Items used
as <search condition> in WHERE, HAVING, JOIN ON, CASE WHEN clauses.
The flag is at the parse time.
These expressions must be evaluated using val_bool() rather than val_int().
Note, the optimizer creates more Items which are used as search conditions.
Most of these items are not marked with IS_COND yet. This is OK for now,
but eventually these Items can also be fixed to have the flag.
- Adding a method Item::is_cond() which tests if the Item has the IS_COND flag.
- Implementing Item_cache_bool. It evaluates the cached expression using
val_bool() rather than val_int().
Overriding Type_handler_bool::Item_get_cache() to create Item_cache_bool.
- Implementing Item::save_bool_in_field(). It uses val_bool() rather than
val_int() to evaluate the expression.
- Implementing Type_handler_bool::Item_save_in_field()
using Item::save_bool_in_field().
- Fixing all Item_bool_func descendants to implement a virtual val_bool()
rather than a virtual val_int().
- To find places where val_int() should be fixed to val_bool(), a few
DBUG_ASSERT(!is_cond()) where added into val_int() implementations
of selected (most frequent) classes:
Item_field
Item_str_func
Item_datefunc
Item_timefunc
Item_datetimefunc
Item_cache_bool
Item_bool_func
Item_func_hybrid_field_type
Item_basic_constant descendants
- Fixing all places where DBUG_ASSERT() happened during an "mtr" run
to use val_bool() instead of val_int().
A mixture of a multi-byte *TEXT column and a short binary column
produced a too large column.
For example, COALESCE(tinytext_utf8mb4, short_varbinary)
produced a BLOB column instead of an expected TINYBLOB.
- Adding a virtual method Type_all_attributes::character_octet_length(),
returning max_length by default.
- Overriding Item_field::character_octet_length() to extract
the octet length from the underlying Field.
- Overriding Item_ref::character_octet_length() to extract
the octet length from the references Item (e.g. as VIEW fields).
- Fixing Type_numeric_attributes::find_max_octet_length() to
take the octet length using the new method character_octet_length()
instead of accessing max_length directly.
Fixing applying the COLLATE clause to a parameter caused an error error:
COLLATION '...' is not valid for CHARACTER SET 'binary'
Fix:
- Changing the collation derivation for a non-prepared Item_param
to DERIVATION_IGNORABLE.
- Allowing to apply any COLLATE clause to expressions with DERIVATION_IGNORABLE.
This includes:
1. A non-prepared Item_param
2. An explicit NULL
3. Expressions derived from #1 and #2
For example:
SELECT ? COLLATE utf8mb_unicode_ci;
SELECT NULL COLLATE utf8mb_unicode_ci;
SELECT CONCAT(?) COLLATE utf8mb_unicode_ci;
SELECT CONCAT(NULL) COLLATE utf8mb_unicode_ci
- Additional change: preserving the collation of an expression when
the expression gets assigned to a PS parameter and evaluates to SQL NULL.
Before this change, the collation of the parameter was erroneously set
to &my_charset_binary.
- Additional change: removing the multiplication to mbmaxlen from the
fix_char_length_ulonglong() argument, because the multiplication already
happens inside fix_char_length_ulonglong().
This fixes a too large column size created for a COLLATE clause.
Some fixes related to commit f838b2d799 and
Rows_log_event::do_apply_event() and Update_rows_log_event::do_exec_row()
for system-versioned tables were provided by Nikita Malyavin.
This was required by test versioning.rpl,trx_id,row.
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.
Functions extracting non-negative datetime components:
- YEAR(dt), EXTRACT(YEAR FROM dt)
- QUARTER(td), EXTRACT(QUARTER FROM dt)
- MONTH(dt), EXTRACT(MONTH FROM dt)
- WEEK(dt), EXTRACT(WEEK FROM dt)
- HOUR(dt),
- MINUTE(dt),
- SECOND(dt),
- MICROSECOND(dt),
- DAYOFYEAR(dt)
- EXTRACT(YEAR_MONTH FROM dt)
did not set their max_length properly, so in the DECIMAL
context they created a too small DECIMAL column, which
led to the 'Out of range value' error.
The problem is that most of these functions historically
returned the signed INT data type.
There were two simple ways to fix these functions:
1. Add +1 to max_length.
But this would also change their size in the string context
and create too long VARCHAR columns, with +1 excessive size.
2. Preserve max_length, but change the data type from INT to INT UNSIGNED.
But this would break backward compatibility.
Also, using UNSIGNED is generally not desirable,
it's better to stay with signed when possible.
This fix implements another solution, which it makes all these functions
work well in all contexts: int, decimal, string.
Fix details:
- Adding a new special class Type_handler_long_ge0 - the data type
handler for expressions which:
* should look like normal signed INT
* but which known not to return negative values
Expressions handled by Type_handler_long_ge0 store in Item::max_length
only the number of digits, without adding +1 for the sign.
- Fixing Item_extract to use Type_handler_long_ge0
for non-negative datetime components:
YEAR, YEAR_MONTH, QUARTER, MONTH, WEEK
- Adding a new abstract class Item_long_ge0_func, for functions
returning non-negative datetime components.
Item_long_ge0_func uses Type_handler_long_ge0 as the type handler.
The class hierarchy now looks as follows:
Item_long_ge0_func
Item_long_func_date_field
Item_func_to_days
Item_func_dayofmonth
Item_func_dayofyear
Item_func_quarter
Item_func_year
Item_long_func_time_field
Item_func_hour
Item_func_minute
Item_func_second
Item_func_microsecond
- Cleanup: EXTRACT(QUARTER FROM dt) created an excessive VARCHAR column
in string context. Changing its length from 2 to 1.
During the 10.5->10.6 merge please use the 10.6 code on conflicts.
This is the 10.5 version of the patch (a backport of the 10.6 version).
Unlike 10.6 version, it makes changes in plugin/type_inet/sql_type_inet.*
rather than in sql/sql_type_fixedbin.h
Item_bool_rowready_func2, Item_func_between, Item_func_in
did not check if a not-NULL argument of an arbitrary data type
can produce a NULL value on conversion to INET6.
This caused a crash on DBUG_ASSERT() in conversion failures,
because the function returned SQL NULL for something that
has Item::maybe_null() equal to false.
Adding setting NULL-ability in such cases.
Details:
- Removing the code in Item_func::setup_args_and_comparator()
performing character set aggregation with optional narrowing.
This aggregation is done inside Arg_comparator::set_cmp_func_string().
So this code was redundant
- Removing Item_func::setup_args_and_comparator() as it git simplified to
just to two lines:
convert_const_compared_to_int_field(thd);
return cmp->set_cmp_func(thd, this, &args[0], &args[1], true);
Using these lines directly in:
- Item_bool_rowready_func2::fix_length_and_dec()
- Item_func_nullif::fix_length_and_dec()
- Adding a new virtual method:
- Type_handler::Item_bool_rowready_func2_fix_length_and_dec().
- Adding tests detecting if the data type conversion can return SQL NULL into
the following methods of Type_handler_inet6:
- Item_bool_rowready_func2_fix_length_and_dec
- Item_func_between_fix_length_and_dec
- Item_func_in_fix_comparator_compatible_types
This is the 10.6 version of the patch.
Item_bool_rowready_func2, Item_func_between, Item_func_in
did not check if a not-NULL argument of an arbitrary data type
can produce a NULL value on conversion to INET6.
This caused a crash on DBUG_ASSERT() in conversion failures,
because the function returned SQL NULL for something that
has Item::maybe_null() equal to false.
Adding setting NULL-ability in such cases.
Details:
- Removing the code in Item_func::setup_args_and_comparator()
performing character set aggregation with optional narrowing.
This aggregation is done inside Arg_comparator::set_cmp_func_string().
So this code was redundant
- Removing Item_func::setup_args_and_comparator() as it git simplified to
just to two lines:
convert_const_compared_to_int_field(thd);
return cmp->set_cmp_func(thd, this, &args[0], &args[1], true);
Using these lines directly in:
- Item_bool_rowready_func2::fix_length_and_dec()
- Item_func_nullif::fix_length_and_dec()
- Adding a new virtual method:
- Type_handler::Item_bool_rowready_func2_fix_length_and_dec().
- Adding tests detecting if the data type conversion can return SQL NULL into
the following methods of Type_handler_fbt:
- Item_bool_rowready_func2_fix_length_and_dec
- Item_func_between_fix_length_and_dec
- Item_func_in_fix_comparator_compatible_types
(Variant#3: Allow cross-charset comparisons, use a special
CHARSET_INFO to create lookup keys. Review input addressed.)
Equalities that compare utf8mb{3,4}_general_ci strings, like:
WHERE ... utf8mb3_key_col=utf8mb4_value (MB3-4-CMP)
can now be used to construct ref[const] access and also participate
in multiple-equalities.
This means that utf8mb3_key_col can be used for key-lookups when
compared with an utf8mb4 constant, field or expression using '=' or
'<=>' comparison operators.
This is controlled by optimizer_switch='cset_narrowing=on', which is
OFF by default.
IMPLEMENTATION
Item value comparison in (MB3-4-CMP) is done using utf8mb4_general_ci.
This is valid as any utf8mb3 value is also an utf8mb4 value.
When making index lookup value for utf8mb3_key_col, we do "Charset
Narrowing": characters that are in the Basic Multilingual Plane (=BMP) are
copied as-is, as they can be represented in utf8mb3. Characters that are
outside the BMP cannot be represented in utf8mb3 and are replaced
with U+FFFD, the "Replacement Character".
In utf8mb4_general_ci, the Replacement Character compares as equal to any
character that's not in BMP. Because of this, the constructed lookup value
will find all index records that would be considered equal by the original
condition (MB3-4-CMP).
Approved-by: Monty <monty@mariadb.org>
When aggregating pairs BIT+NULL and NULL+BIT for result, e.g.
in COALESCE(), preserve the BIT data type (ignore explicit NULLs).
The same fix applied to YEAR.
The MDEV-29693 conflict resolution is from Monty, as well as is
a bug fix where ANALYZE TABLE wrongly built histograms for
single-column PRIMARY KEY.
Also includes a fix for safe_malloc error reporting.
Other things:
- Copied main.log_slow from 10.4 to avoid mtr issue
Disabled test:
- spider/bugfix.mdev_27239 because we started to get
+Error 1429 Unable to connect to foreign data source: localhost
-Error 1158 Got an error reading communication packets
- main.delayed
- Bug#54332 Deadlock with two connections doing LOCK TABLE+INSERT DELAYED
This part is disabled for now as it fails randomly with different
warnings/errors (no corruption).
Raise notes if indexes cannot be used:
- in case of data type or collation mismatch (diferent error messages).
- in case if a table field was replaced to something else
(e.g. Item_func_conv_charset) during a condition rewrite.
Added option to write warnings and notes to the slow query log for
slow queries.
New variables added/changed:
- note_verbosity, with is a set of the following options:
basic - All old notes
unusable_keys - Print warnings about keys that cannot be used
for select, delete or update.
explain - Print unusable_keys warnings for EXPLAIN querys.
The default is 'basic,explain'. This means that for old installations
the only notable new behavior is that one will get notes about
unusable keys when one does an EXPLAIN for a query. One can turn all
of all notes by either setting note_verbosity to "" or setting sql_notes=0.
- log_slow_verbosity has a new option 'warnings'. If this is set
then warnings and notes generated are printed in the slow query log
(up to log_slow_max_warnings times per statement).
- log_slow_max_warnings - Max number of warnings written to
slow query log.
Other things:
- One can now use =ALL for any 'set' variable to set all options at once.
For example using "note_verbosity=ALL" in a config file or
"SET @@note_verbosity=ALL' in SQL.
- mysqldump will in the future use @@note_verbosity=""' instead of
@sql_notes=0 to disable notes.
- Added "enum class Data_type_compatibility" and changing the return type
of all Field::can_optimize*() methods from "bool" to this new data type.
Reviewer & Co-author: Alexander Barkov <bar@mariadb.com>
- The code that prints out the notes comes mainly from Alexander
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.
