- Adding new virtual methods in Type_handler:
* Column_definition_prepare_stage1()
* Column_definition_prepare_stage2()
* calc_pack_length()
- Using new methods to remove type specific code in:
* Global function calc_pack_length()
* Column_definition::prepare_create_field()
* The loop body mysql_prepare_create_table()
* Column_definition::sp_prepare_create_field()
Introducing a new class Type_holder (used internally in sql_union.cc),
to reuse exactly the same data type attribute aggregation Type_handler API
for hybrid functions and UNION.
This fixes a number of bugs in UNION:
- MDEV-9495 Wrong field type for a UNION of a signed and an unsigned INT expression
- MDEV-9497 UNION and COALESCE produce different field types for DECIMAL+INT
- MDEV-12594 UNION between fixed length double columns does not always preserve scale
- MDEV-12595 UNION converts INT to BIGINT
- MDEV-12599 UNION is not symmetric when mixing INT and CHAR
Details:
- sql_union.cc: Reusing attribute aggregation for UNION.
Adding new methods:
* st_select_lex_unit::join_union_type_handlers()
* st_select_lex_unit::join_union_type_attributes()
* st_select_lex_unit::join_union_item_types()
Removing the old join_types()-based code.
- Changing Type_handler::Item_hybrid_func_fix_attributes()
to accept "name", Type_handler_hybrid_field_type, Type_all_attributes
as three separate parameters instead of a single Item_hybrid_func parameter,
to make it possible to pass both Item_hybrid_func and Type_holder.
- Moving the former special GEOMETRY and ENUM/SET attribute aggregation code
from Item_type_holder::join_types() to
* Type_handler_typelib::Item_hybrid_func_fix_attributes().
* Type_handler_geometry::Item_hybrid_func_fix_attrubutes().
This makes GEOMETRY/ENUM/SET symmetric with all other data types
(from the UNION point of view).
Removing Item_type_holder::join_types() and Item_type_holder::get_full_info().
- Adding new methods into Type_all_attributes:
* Type_all_attributes::set_geometry_type() and
Item_hybrid_func::set_geometry_type().
* Adding Type_all_attributes::get_typelib().
* Adding Type_all_attributes::set_typelib().
- Adding Type_handler_typelib as a common parent for
Type_handler_enum and Type_handler_set, to avoid code duplication: they have
already had two common methods, and we're adding one more shared method.
- Adding Type_all_attributes::set_maybe_null(), as some type handlers
may want to set maybe_null (e.g. Type_handler_geometry) during data type
attribute aggregation.
- Changing Type_geometry_attributes() to accept Type_handler
and Type_all_attributes as two separate parameters, instead
of a single Item parameter, to make it possible to pass Type_holder.
- Adding Item_args::add_argument().
- Moving Item_args::alloc_arguments() from "protected" to "public".
- Moving Item_type_holder::Item_type_holder() from item.cc to item.h, as
now it's very simple.
Btw, this constructor should probably be eventually removed.
It's now used only in sql_show.cc, which could be modified to use
Item_return_decimal (for symmetry with Item_return_xxx created for all
other data types). Or, another option: remove all Item_return_xxx and
use Item_type_holder for all data types instead.
- storage/tokudb/mysql-test/tokudb/r/type_float.result
Recording new results (MDEV-12594).
- mysql-test/r/cte_recursive.result
Recording new results (MDEV-9497)
- mysql-test/r/subselect*.result
Recording new results (MDEV-12595)
- mysql-test/r/metadata.result
Recording new results (MDEV-9495)
- mysql-test/r/temp_table.result
Recording new results (MDEV-12594)
- mysql-test/r/type_float.result
Recording new results (MDEV-12594)
This is a join patch fixing these two bugs:
MDEV-12560 Wrong data type for SELECT NULL UNION SELECT Point(1,1)
MDEV-12665 Hybrid functions do not preserve geometry type
1. Implementing the task according to the description:
a. Adding Type_handler::type_handler_for_tmp_table().
b. Adding Type_handler::type_handler_for_union_table.
c. Adding helper methods Type_handler::varstring_type_handler(const Item*),
Type_handler::blob_type_handler(const Item*)
d. Removing Item::make_string_field() and
Item_func_group_concat::make_string_field().
They are not needed any more.
e. Simplifying Item::tmp_table_field_from_field_type() to just two lines.
f. Renaming Item_type_holder::make_field_by_type() and implementing
virtual Item_type_holder::create_tmp_field() instead.
The new implementation is also as simple as two lines.
g. Adding a new virtual method Type_all_attributes::get_typelib(),
to access to TYPELIB definitions for ENUM and SET columns.
h. Simplifying the code branch for TIME_RESULT, DECIMAL_RESULT, STRING_RESULT
in Item::create_tmp_field(). It's now just one line.
i. Implementing Type_handler_enum::make_table_field() and
Type_handler_set::make_table_field().
2. Code simplification in Field_str constructor calls.
a. Changing the "CHARSET_INFO *cs" argument in constuctors for Field_str
and its descendants to "const DTCollation &collation". This is to
avoid two step initialization:
- setting Field_str::derivation and Field_str::repertoire to the
default values first
- then resetting them using:
set_derivation(item->derivation, item->repertoire).
b. Removing Field::set_derivation()
c. Adding a new constructor DTCollation(CHARSET_INFO *cs),
for the old code compatibility.
3. Changes in test results
As a side effect some test results have changed, because
in the old version Item::make_string_field() converted
TINYBLOB to VARCHAR(255). Now TINYBLOB is preserved.
a. sp-row.result
This query:
CREATE TABLE t1 AS SELECT tinyblob_sp_variable;
Now preserves TINYBLOB as the data type.
Before the patch a VARCHAR(255) was created.
b. gis-debug.result
This is a debug test, to make sure that + and - operators
are commutative and non-commutative correspondingly.
The exact data type is not really important.
(But anyway, it now chooses a better data type that fits the result)
This is a joint patch for:
- MDEV-12426 Add Field::type_handler()
- MDEV-12432 Range optimizer for ENUM and SET does not return "Impossible WHERE" in some case
With the new type handler approach being added to Field, it was easier to fix
MDEV-12432 rather than to reproduce the old ENUM/SET behavior.
The patch does the following:
1. Adds Field::type_handler(), according to the task description.
2. Fixes the asymmetry between Fields and Items of ENUM and SET field types.
Field_enum::cmp_type() returned INT_RESULT
Item*::cmp_type() returned STRING_RESULT for ENUM and SET expressions
This asymmetry was originally done for easier coding in the optimizer sources.
However, in 10.1 we moved a lot of code to methods of the class Field:
- test_if_equality_guarantees_uniqueness()
- can_be_substituted_to_equal_item()
- get_equal_const_item()
- can_optimize_keypart_ref()
- can_optimize_hash_join()
- can_optimize_group_min_max()
- can_optimize_range()
- can_optimize_outer_join_table_elimination()
As of 10.2 only a few lines of the code in opt_range.cc, field.cc and field.h
still relayed on the fact that Field_enum::cmp_type() returns INT_RESULT:
- Some asserts in field.cc
- Field_year::get_copy_func()
- Item_func_like::get_mm_leaf()
- Item_bool_func::get_mm_leaf()
These lines have been fixed.
3. Item_bool_func::get_mm_leaf() did not work well for ENUM/SET,
see MDEV-12432. So the ENUM/SET code was rewritten, and the relevant
code in Field_enum::store() and Field_set::store() was fixed to
properly return errors to the caller.
4. The result of Field_decimal::result_type() was changed from REAL_RESULT
to DECIMAL_RESULT. Data type aggregation (e.g. in COALESCE()) is now more
precise for old DECIMAL, because Item::decimal_precision() now goes through
the DECIMAL_RESULT branch. Earlier it went through the REAL_RESULT branch.
- Adding Type_handler::make_table_field() and moving pieces of the code
from Item::tmp_table_field_from_field_type() to virtual implementations
for various type handlers.
- Adding a new Type_all_attributes, to access to Item's extended
attributes, such as decimal_precision() and geometry_type().
- Adding a new class Record_addr, to pass record related information
to Type_handler methods (ptr, null_ptr and null_bit) as a single structure.
Note, later it will possibly be extended for BIT-alike field purposes,
by adding new members (bit_ptr_arg, bit_ofs_arg).
- Moving the code from Field_new_decimal::create_from_item()
to Type_handler_newdecimal::make_table_field().
- Removing Field_new_decimal() and Field_geom() helper constructor
variants that were used for temporary field creation.
- Adding Item_field::type_handler(), Field::type_handler() and
Field_blob::type_handler() to return correct type handlers for
blob variants, according to Field_blob::packlength.
- Adding Type_handler_blob_common, as a common parent for
Type_handler_tiny_blob, Type_handler_blob, Type_handler_medium_blob
and Type_handler_long_blob.
- Implementing Type_handler_blob_common::Item_hybrid_func_fix_attributes().
It's needed for cases when TEXT variants of different character sets are mixed
in LEAST, GREATEST, CASE and its abreviations (IF, IFNULL, COALESCE), e.g.:
CREATE TABLE t1 (
a TINYTEXT CHARACTER SET latin1,
b TINYTEXT CHARACTER SET utf8
);
CREATE TABLE t2 AS SELECT COALESCE(a,b) FROM t1;
Type handler aggregation returns TINYTEXT as a common data type
for the two columns. But as conversion from latin1 to utf8
happens for "a", the maximum possible length of "a" grows from 255 to 255*3.
Type_handler_blob_common::Item_hybrid_func_fix_attributes() makes sure
to update the blob type handler according to max_length.
- Adding Type_handler::blob_type_handler(uint max_octet_length).
- Adding a few m_type_aggregator_for_result.add() pairs, because
now Item_xxx::type_handler() can return pointers to type_handler_tiny_blob,
type_handler_blob, type_handler_medium_blob, type_handler_long_blob.
Before the patch only type_handler_blob was possible result of type_handler().
- Making type_handler_tiny_blob, type_handler_blob, type_handler_medium_blob,
type_handler_long_blob public.
- Removing the condition in Item_sum_avg::create_tmp_field()
checking Item_sum_avg::result_type() against DECIMAL_RESULT.
Now both REAL_RESULT and DECIMAL_RESULT are symmetrically handled
by tmp_table_field_from_field_type().
- Removing Item_geometry_func::create_field_for_create_select(),
as the inherited version perfectly works.
- Fixing Item_func_as_wkb::field_type() to return MYSQL_TYPE_LONG_BLOB
rather than MYSQL_TYPE_BLOB. It's needed to make sure that
tmp_table_field_from_field_type() creates a LONGBLOB field for AsWKB().
- Fixing Item_func_as_wkt::fix_length_and_dec() to set max_length to
UINT32_MAX rather than MAX_BLOB_WIDTH, to make sure that
tmp_table_field_from_field_type() creates a LONGTEXT field for AsWKT().
- Removing Item_func_set_user_var::create_field_for_create_select(),
as the inherited version works fine.
- Adding Item_func_get_user_var::create_field_for_create_select() to
make sure that "CREATE TABLE t1 AS SELECT @string_user variable"
always creates a field of LONGTEXT/LONGBLOB type.
- Item_func_ifnull::create_field_for_create_select()
behavior has changed. Before the patch it passed set_blob_packflag=false,
which meant to create LONGBLOB for all blob variants.
Now it takes into account max_length, which gives better column
data types for:
CREATE TABLE t2 AS SELECT IFNULL(blob_column1, blob_column2) FROM t1;
- Fixing Item_func_nullif::fix_length_and_dec() to use
set_handler(args[2]->type_handler()) instead of
set_handler_by_field_type(args[2]->field_type()).
This is needed to distinguish between BLOB variants.
- Implementing Item_blob::type_handler(), to make sure to create
proper BLOB field variant, according to max_length, for queries like:
CREATE TABLE t1 AS
SELECT some_blob_field FROM INFORMATION_SCHEMA.SOME_TABLE;
- Fixing Item_field::real_type_handler() to make sure that
the code aggregating fields for UNION gets a proper BLOB
variant type handler from fields.
- Adding a special code into Item_type_holder::make_field_by_type(),
to make sure that after aggregating field types it also properly
takes into account max_length when mixing TEXT variants of different
character sets and chooses a proper TEXT variant:
CREATE TABLE t1 (
a TINYTEXT CHARACTER SET latin1,
b TINYTEXT CHARACTER SET utf8
);
CREATE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;
- Adding tests, for better coverage of IFNULL, NULLIF, UNION.
- The fact that tmp_table_field_from_field_type() now takes
into account BLOB variants (instead of always creating LONGBLOB),
tests results for WEIGHT_STRING() and NULLIF() and UNION
have become more precise.
This patch does the following:
1. Adds a new method Type_handler_hybrid_field_type::aggregate_for_min_max()
- For non-traditional data types it uses
type_handler_data->m_type_aggregator_for_result.find_handler()
This allows pluggable data types to define in the future their
own behavior of the result data type detection for LEAST/GREATEST.
Also, this disallows expressions of the GEOMETRY data type
(and its variants such as POINT) to be mixed in with
numeric and temporal data types in LEAST/GREATEST.
- For traditional data types it reproduces the old behavior of
the result data type detection (but not attributes, see below).
2. Adds a new virtual method Type_handler::Item_func_min_max_fix_attributes()
and reuses as much as possible the code that calculates data type attributes
for CASE-alike functions (e.g. CASE..THEN, COALESCE, IF).
As the old code responsible for attributes calculation in the old
implementation of Item_func_min_max::fix_length_and_dec()
was not fully correct, this automatically fixes the following bugs:
- MDEV-12497 Wrong data type for LEAST(latin1_expr, utf8_expr)
The old fix_length_and_dec() calculated max_length before
character set aggregation. Now max_length is calculated after, in
Item_func::count_string_length() called from
Item_func::aggregate_attributes_string() called from
Type_handler_string_result::Item_hybrid_func_fix_attributes() called from
Type_handler::Item_func_min_max_fix_attributes() called from
Item_func_min_max::fix_length_and_dec().
- MDEV-12504 Wrong data type for LEAST(date_expr,time_expr)
The old fix_length_and_dec() simply used the maximum of max_length
among all arguments to set its own max_length and did not take
into account that a mixture of DATE and TIME becomes DATETIME.
Now this is correctly handled by:
Type_handler_datetime_common::Item_hybrid_func_fix_attributes() called from
Type_handler::Item_func_min_max_fix_attributes() called from
Item_func_min_max::fix_length_and_dec().
3. Removes the old implementation of Item_func_min_max::fix_length_and_dec()
and replaces it to calls of the new methods.
4. Cleanup: moves the code related to unsigned_flag processing
from Type_handler_hybrid_field_type::aggregate_for_result()
to Type_handler_int_result::Item_hybrid_func_fix_attributes().
This is done:
- to avoid code duplication in
Type_handler_hybrid_field_type::aggregate_for_min_max()
- to get rid of one more call for field_type(), which is unfriendly
to the conceipt of pluggable data types.
- Adding a new virtual method Type_handler::Item_time_precision()
- Adding a new virtual method Type_handler::Item_datetime_precision()
- Removing Item::temporal_precision() and adding Item::time_precision()
and Item::datetime_precision() instead.
- Moving Item_func_convert_tz::fix_length_and_dec() from item_timefunc.cc
to item_timefunc.h. It's only two lines, and we're changing it anyway.
- Removing Item_temporal_typecast::fix_length_and_dec_generic(),
moving this code to
Type_handler::Item_{date|time|datetime}_typecast_fix_length_and_dec().
This allows to get rid of one more field_type() call.
Also, in the old reduction, Item_date_typecast::fix_length_and_dec()
unnecessarily called args[0]->temporal_precision(). The new reduction
does not call args[0]->datetime_precision(), as DATE does not
have fractional digits.
This patch implements MDEV-12514 according to the task descriptions.
It automatically fixes:
MDEV-12515 Wrong value when storing DATE_ADD() and ADDTIME() to a numeric field
Additionally:
a. Moves Item_func::set_attributes_temporal() to
Type_str_attributes::fix_attributes_temporal(),
which is a more proper place and name for it.
b. Continues replacing calls for:
set_handler_by_field_type(MYSQL_TYPE_XXX)
to corresponding:
set_handler(&type_handler_xxx)
which is faster.
Note, we should eventually get rid of almost all set_handler_by_field_type().
c. Makes type_handler_string, type_handler_time2, type_handler_newdate,
type_handler_datetime2 public.
(all built-in handlers will become public eventually)
d. Removing Item_temporal_func::sql_mode, as it was not used.
This patch makes the following changes (according to the task description):
- Adds Type_handler::Item_func_round_fix_length_and_dec().
- Splits the code from Item_func_round::fix_length_and_dec() into new
Item_func_round methods fix_arg_int(), fix_arg_decimal(), fix_arg_double().
- Calls the new Item_func_round methods from the relevant implementations of
Type_handler_xxx::Item_func_round_fix_length_and_dec().
- Adds a new error message ER_ILLEGAL_PARAMETER_DATA_TYPE_FOR_OPERATION
- Makes ROUND() return the new error for GEOMETRY
Additionally:
- Inherits Item_func_round directly from Item_func_numhybrid as it
uses nothing from Item_func_num1.
- Fixes "MDEV-12000 ROUND(expr,const_expr_returning_NULL) creates DOUBLE(0,0)".
Now if args[1] returns NULL, the data type is set to DOUBLE with
NOT_FIXED_DEC decimals instead of 0 decimals.
This patch also fixes:
MDEV-11815 SP variables of temporal data types do not replicate correctly
Temporal values are now printed in temporal literal format, with the
SQL-standard data type prefix:
TIME'10:20:30', DATE'2001-01-01', TIMESTAMP'2001-01-01 10:20:30'
Previously temporal values were printed using the text string notation, e.g.
_latin1'10:20:30' COLLATE latin1_swedish_ci, hence the bug.
The problem happened because Item_ident_for_show::field_type() always
returned MYSQL_TYPE_DOUBLE and ignored the actual data type of the
referenced Field. As a result, the execution always used
Item_ident_for_show::val_real() to send the default value of the field,
so most default values for non-numeric types were displayed as '0'.
This patch:
1. Cleanup:
a. Removes Send_field::charsetnr, as it's been unused since
introduction of Item::charset_for_protocol() in MySQL-5.5.
b. Adds the "const" qualifier to Field::char_length().
This is needed for (5.a), see below.
2. Introduces a new virtual method Type_handler::charset_for_protocol(),
returning item->collation.collation for string data types, or
&my_charset_bin for non-string data types.
3. Changes Item::charset_for_protocol() from virtual to non-virtual.
It now calls type_handler()->charset_for_protocol().
As a good side effect, duplicate code in Item::charset_for_protocol() and
Item_temporal_hybrid_func::charset_for_protocol() is now gone.
4. Fixes Item_ident_for_show::field_type() to correctly return
its data type according to the data type of the referenced field.
This actually fixes the problem reported in MDEV-11672.
Now the default value is sent using a correct method, e.g.
val_str() for VARCHAR/TEXT, or val_int() for INT/BIGINT.
This required additional changes:
a. in DBUG_ASSERT in Protocol::store(const char *,size_t,CHARSET_INFO),
This method is now used by mysqld_list_fields(), which
(unlike normal SELECT queries) does not set
field_types/field_pos/field_count.
b. Item_ident_for_show::Item_ident_for_show() now set standard attributes
(collation, decimals, max_length, unsigned_flag) according to the
referenced field, to make charset_for_protocol() return the correct
value and to make mysqld_list_fields() correctly send default
values.
5. In order to share the code between Item_field::set_field() and
Item_ident_for_show::Item_ident_for_show():
a. Introduces a new method Type_std_attributes::set(const Field*)
b. To make (a) possible, moves Item::fix_char_length() from Item
to Type_std_attributes, also moves char_to_byte_length_safe()
from item.h to sql_type.h
c. Additionally, moves Item::fix_length_and_charset() and
Item::max_char_length() from Item to Type_std_attributes.
This is not directly needed for the fix and is done just for symmetry
with fix_char_length(), as these three methods are directly related
to each other.
This patch fixes a number of data type aggregation problems in IN and CASE:
- MDEV-11497 Wrong result for (int_expr IN (mixture of signed and unsigned expressions))
- MDEV-11514 IN with a mixture of TIME and DATETIME returns a wrong result
- MDEV-11554 Wrong result for CASE on a mixture of signed and unsigned expressions
- MDEV-11555 CASE with a mixture of TIME and DATETIME returns a wrong result
1. The problem reported in MDEV-11514 and MDEV-11555 was in the wrong assumption
that items having the same cmp_type() can reuse the same cmp_item instance.
So Item_func_case and Item_func_in used a static array of cmp_item*,
one element per one XXX_RESULT.
TIME and DATETIME cannot reuse the same cmp_item, because arguments of
these types are compared very differently. TIME and DATETIME must have
different instances in the cmp_item array. Reusing the same cmp_item
for TIME and DATETIME leads to unexpected result and unexpected warnings.
Note, after adding more data types soon (e.g. INET6), the problem would
become more serious, as INET6 will most likely have STRING_RESULT, but
it won't be able to reuse the same cmp_item with VARCHAR/TEXT.
This patch introduces a new class Predicant_to_list_comparator,
which maintains an array of cmp_items, one element per distinct
Type_handler rather than one element per XXX_RESULT.
2. The problem reported in MDEV-11497 and MDEV-11554 happened because
Item_func_in and Item_func_case did not take into account the fact
that UNSIGNED and SIGNED values must be compared as DECIMAL rather than INT,
because they used item_cmp_type() to aggregate the arguments.
The relevant code now resides in Predicant_to_list_comparator::add_value()
and uses Type_handler_hybrid_field_type::aggregate_for_comparison(),
like Item_func_between does.
This patch implements the task according to the description:
1. The old code from Item_func_in::fix_length_and_dec() was decomposed
into smaller methods:
- all_items_are_consts()
- compatible_types_scalar_bisection_possible()
- compatible_types_row_bisection_possible()
- fix_in_vector()
- fix_for_scalar_comparison_using_bisection()
- fix_for_scalar_comparison_using_cmp_items()
- fix_for_row_comparison_using_bisection()
- fix_for_row_comparison_using_cmp_items()
The data type dependend pieces where moved as methods to Type_handler.
2. Splits in_datetime into separate:
- in_datetime, for DATETIME and DATE,
- in_time, for TIME
to make the code more symmetric across data types.
Additionally:
- Adds a test func_debug.test to see which calculation strategy
(bisect or no bisect) is chosen to handle IN with various arguments.
- Adds a new helper method (to avoid duplicate code):
cmp_item_rows::prepare_comparators()
- Changes the propotype for cmp_item_row::alloc_comparators(),
to avoid duplicate code, and to use less current_thd.
- Changes "friend" sections in cmp_item_row and in_row from
an exact Item_func_in method to the entire class Item_func_in,
as their internals are now needed in multiple Item_func_in methods.
- Added more comments (e.g. on bisection, on the problem reported in MDEV-11511)
- Removes "Item_result Item_func_opt_neg::m_compare_type" and introduces
"Type_handler_hybrid_field_type Item_func_opt_neg::m_comparator" instead.
- Removes Item_func_between::compare_as_dates, because
the new member m_comparator now contains the precise information
about the data type that is used for comparison, which is important
for TIME vs DATETIME.
- Adds a new method:
Type_handler_hybrid_field_type::aggregate_for_comparison(const Type_handler*),
as a better replacement for item_cmp_type(), which additionally can handle
TIME vs DATE/DATETIME/TIMESTAMP correctly. Additionally, it correctly
handles TIMESTAMP which fixes the problem reported in MDEV-11482.
The old compare_as_dates/find_date_time_item() based code didn't handle
comparison between TIME and TIMESTAMP correctly and erroneously used TIME
comparison instead of DATETIME comparison.
- Adds a new method:
Type_handler_hybrid_field_type::aggregate_for_comparison(Item **, uint nitems),
as a better replacement for agg_cmp_type(), which can handle TIME.
- Splits Item_func_between::val_int() into pieces val_int_cmp_xxx(),
one new method per XXX_RESULT.
- Adds a new virtual method Type_handler::Item_func_between_val_int()
whose implementations use Item_func_between::val_int_cmp_xxx().
- Makes type_handler_longlong and type_handler_newdecimal public,
as they are now needed in item_cmpfunc.cc.
Note:
This patch does not change Item_func_in to use the new aggregation methods,
so it still uses collect_cmp_type()/item_cmp_type() based aggregation.
Item_func_in will be changed in a separate patch and item_cmp_type() will be
removed.
