This is another attempt to fix the bug mdev-12992.
This patch introduces st_select_lex::context_analysis_place for
the place in SELECT where context analysis is currently performed.
It's similar to st_select_lex::parsing_place, but it is used at
the preparation stage.
This is actually a legacy bug:
SQL_SELECT::test_quick_select() was called
with SQL_SELECT::head not set.
It looks like that this problem can be
reproduced only on queries with ORDER BY
that use IN predicates converted to semi-joins.
This patch corrects the fix for bug mdev-7599.
When the min/max optimization of the function
opt_sum_query() optimizes away all tables of
a subquery it should not ever be rolled back.
If the optimizer chose an execution plan where
a semi-join nest were materialized and the
result of materialization was scanned to access
other tables by ref access it could build a key
over columns of the tables from the nest that
were actually inaccessible.
The patch performs a proper check whether a key
that uses columns of the tables from a materialized
semi-join nest can be employed to access outer tables.
This excludes MDEV-12472 (InnoDB should accept XtraDB parameters,
warning that they are ignored). In other words, MariaDB 10.3 will not
recognize any XtraDB-specific parameters.
This corrects the patch for mdev-10006.
The current code supports only those semi-join nests that are placed at
the join top level. So such nests cannot depend on other tables or nests.
This is a joint patch fixing the following problems:
MDEV-12875 Wrong VIEW column data type for COALESCE(int_column)
MDEV-12886 Different default for INT and BIGINT column in a VIEW for a SELECT with ROLLUP
MDEV-12916 Wrong column data type for an INT field of a cursor-anchored ROW variable
All above problem happened because the global function ::create_tmp_field()
called the top-level Item::create_tmp_field(), which made some tranformation
for INT-result data types. For example, INT(11) became BIGINT(11), because 11
is a corner case and it's not known if it fits or does not fit into INT range,
so Item::create_tmp_field() converted it to BIGINT(11) for safety.
The main idea of this patch is to avoid such tranformations.
1. Fixing Item::create_tmp_field() not to have a special case for INT_RESULT.
Item::create_tmp_field() is changed not to have a special case
for INT_RESULT (which earlier made a decision based on Item's max_length).
It now calls tmp_table_field_from_field_type() for INT_RESULT,
therefore preserves the original data type (e.g. INT, YEAR) without
conversion to BIGINT.
This change is valid, because a number of recent fixes
(e.g. in Item_func_int, Item_hybrid_func, Item_int, Item_splocal)
guarantee that item->type_handler() now properly returns
type_handler_long vs type_handler_longlong. So no adjustment by length
is needed any more for Items returning INT_RESULT.
After this change, Item::create_tmp_field() calls
tmp_table_field_from_field_type() for all XXX_RESULT, except REAL_RESULT.
2. Fixing Item::create_tmp_field() not to have a special case for REAL_RESULT.
Note, the reason for a special case for REAL_RESULT is to have a special
constructor for Field_double(), forcing Field_real::not_fixed to be set
to true.
Taking into account that only Item_sum descendants actually need a special
constructor call Field_double(not_fixed=true), not too loose precision
when mixing individual rows to the aggregate result:
- renaming Item::create_tmp_field() to Item_sum::create_tmp_field().
- changing Item::create_tmp_field() just to call
tmp_table_field_from_field_type() for all XXX_RESULT types.
A special case for REAL_RESULT in Item::create_tmp_field() is now gone.
Item::create_tmp_field() is now symmetric for all XXX_RESULT types,
and now just calls tmp_table_field_from_field_type().
3. Fixing Item_func::create_field_for_create_select() not to have
a special case for STRING_RESULT.
After changes #1 and #2, the code in
Item_func::create_field_for_create_select(), testing result_type(),
becomes useless, because: now Item::create_tmp_field() and
tmp_table_field_from_field_type() do exactly the same thing for all
XXX_RESULT types for Item_func descendants:
a. It calls tmp_table_field_from_field_type for STRING_RESULT directly.
b. For other XXX_RESULT, it goes through Item::create_tmp_field(),
which calls the global function ::create_tmp_field(),
which calls item->create_tmp_field() for FUNC_ITEM,
which calls tmp_table_field_from_field_type() again.
So removing the virtual implementation of
Item_func::create_field_for_create_select().
The inherited Item::create_field_for_create_select() now perfectly
does the job, as it also calls tmp_table_field_from_field_type()
for FUNC_ITEM, independently from XXX_RESULT type.
4. Taking into account #1 and #2, as well as some recent changes,
removing virtual implementations:
- Item_hybrid_func::create_tmp_field()
- Item_hybrid_func::create_field_for_create_select()
- Item_int_func::create_tmp_field()
- Item_int_func::create_field_for_create_select()
- Item_temporal_func::create_field_for_create_select()
The derived versions from Item now perfectly work.
5. Moving a piece of code from create_tmp_field_from_item()
to a new function create_tmp_field_from_item_finalize(),
to reuse it in two places (see #6).
6. Changing the code responsible for BIT->INT/BIGIN tranformation
(which is called for the cases when the created table, e.g. HEAP,
does not fully support BIT) not to call create_tmp_field_from_item(),
because the latter now calls tmp_table_field_from_field_type() instead
of create_tmp_field() and thefore cannot do BIT transformation.
So rewriting this code using a sequence of these calls:
- item->type_handler_long_or_longlong()
- handler->make_and_init_table_field()
- create_tmp_field_from_item_finalize()
7. Miscelaneous changes:
- Moving type_handler_long_or_longlong() from "protected" to "public",
as it's now needed in the global function create_tmp_field().
8. The above changes fixed MDEV-12875, MDEV-12886, MDEV-12916.
So adding tests for these bugs.
MDEV-12858 Out-of-range error for CREATE..SELECT unsigned_int_column+1
MDEV-12859 Out-of-range error for CREATE..SELECT @a:=EXTRACT(MINUTE_MICROSECOND FROM..)
MDEV-12862 Data type of @a:=1e0 depends on the session character set
1. Moving a part of Item::create_tmp_field() into a new helper method
Item::create_tmp_field_int() and reusing it in Item::create_tmp_field()
and Item_func_signed::create_tmp_field().
Fixing the code in Item::create_tmp_field_int() to call
Type_handler::make_table_field() instead of doing "new Field_long[long]"
directly. This change revealed a problem reported in MDEV-12862.
2. Changing the "long vs longlong" cut-off length for
- Item_func::create_tmp_field()
- Item_sum::create_tmp_field()
- Item_func_get_user_var::create_tmp_field()
from MY_INT32_NUM_DECIMAL_DIGITS to (MY_INT32_NUM_DECIMAL_DIGITS - 2).
This fixes MDEV-12858.
After this change, the "convert_int_length" parameter to
Item::create_tmp_field() is not needed any more, because
(MY_INT32_NUM_DECIMAL_DIGITS - 2) is always passed.
So removing the "convert_int_length" parameter.
3. Fixing Item::create_tmp_field() to pass max_char_length() instead
of max_length to the constructor of Field_double().
This fixes MDEV-12862.
4. Additionally, fixing
- Type_handler_{tiny|short|int24|long|longlong}::make_table_field()
- Type_handler_{float|double}::make_table_field()
to pass max_char_length() instead of max_length to Field contructors.
This is needed by the change (1).
5. Adding new tests, and recording new correct results in the old tests in:
- mysql-test/r/type_ranges.result
- storage/tokudb/mysql-test/tokudb/r/type_ranges.result
Significantly reduce the amount of InnoDB, XtraDB and Mariabackup
code changes by defining pfs_os_file_t as something that is
transparently compatible with os_file_t.
In some rare cases queries with UNION ALL
using a derived table specified by
a grouping select with a subquery in WHERE and
impossible HAVING detected after constant row
substitution could hang.
The cause was not a proper return from the
function subselect_single_select_engine::exec()
in the case when the subquery was not optimized
beforehand and the optimization performed
in this function requested for a change of the
subquery engine. This was fixed.
Also a change was applied that avoided execution
of a subquery if impossible having was detected
for the main query at the optimization stage.
When an IN subquery predicate was converted to a semi-join that were
materialized and the result of the materialization happened to be
the last in the execution plan then any conjunctive condition with RAND()
turned out to be lost.
Fixed by attaching this condition to the last top base table.
JOIN_TAB::remove_redundant_bnl_scan_conds() removes select_cond
from a JOIN_TAB if join cache is enabled, and tab->cache_select->cond
is the equal to tab->select_cond.
But after 8d99166c69 the code to initialize join cache was moved
to happen much later than JOIN_TAB::remove_redundant_bnl_scan_conds(),
and that code might, under certain conditions, revert to *not* using
join cache (set_join_cache_denial()).
If JOIN_TAB::remove_redundant_bnl_scan_conds() removes the WHERE
condition from the JOIN_TAB and later set_join_cache_denial() disables
join cache, we end up with no WHERE condition at all.
Fix: move JOIN_TAB::remove_redundant_bnl_scan_conds() to happen
after all possible set_join_cache_denial() calls.
This patch corrects the fix for the bug mdev-10693.
It is critical for the function get_best_combination() not to call
create_ref_for_key() for constant tables.
This bug could manifest itself only in multi-table subqueries where
one of the tables is accessed by a constant primary key.
The usage of windows functions when all tables were optimized away
by min/max optimization were not supported. As result a result,
the queries that used window functions with min/max aggregation
over the whole table returned wrong result sets.
The patch fixed this problem.
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)
The code that chooses between materialization of a non-correlated
IN subquery and its transformation into an EXISTS correlated
subquery assumes that the execution plan for the outer select
has been already built. However it was not always so if subqueries
occurred in the expressions used for ref access to tables of
the outer select. A call of the function create_ref_for_key() in
get_best_combination() could trigger a premature execution of
the above mentioned code when the execution plan structures for
the outer select were not fully built. This could cause a crash
of the server.
The fix postpones the calls of create_ref_for_key() until the
structures for the execution plan is fully built.
- 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.
Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)
Changes:
- This caused some ABI changes
- lex_string_set now uses LEX_CSTRING
- Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
code
- Added item_empty_name and item_used_name to be able to distingush between
items that was given an empty name and items that was not given a name
This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
give the error.
TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
(as part of lower_case_table_names)
This patch fixed some problems that occurred with subqueries that
contained directly or indirectly recursive references to recursive CTEs.
1. A [NOT] IN predicate with a constant left operand and a non-correlated
subquery as the right operand used in the specification of a recursive CTE
was considered as a constant predicate and was evaluated only once.
Now such a predicate is re-evaluated after every iteration of the process
that produces the records of the recursive CTE.
2. The Exists-To-IN transformation could be applied to [NOT] IN predicates
with recursive references. This opened a possibility of materialization
for the subqueries used as right operands. Yet, materialization
is prohibited for the subqueries if they contain a recursive reference.
Now the Exists-To-IN transformation cannot be applied for subquery
predicates with recursive references.
The function st_select_lex::check_subqueries_with_recursive_references()
is called now only for the first execution of the SELECT.
In case of error on opening VIEW (absent table for example) it is still possible to print its definition but some variable is not set (table_list->derived->derived) so it is better do not try to test it when there is safer alternative (table_list itself).
Working features:
CREATE OR REPLACE [TEMPORARY] SEQUENCE [IF NOT EXISTS] name
[ INCREMENT [ BY | = ] increment ]
[ MINVALUE [=] minvalue | NO MINVALUE ]
[ MAXVALUE [=] maxvalue | NO MAXVALUE ]
[ START [ WITH | = ] start ] [ CACHE [=] cache ] [ [ NO ] CYCLE ]
ENGINE=xxx COMMENT=".."
SELECT NEXT VALUE FOR sequence_name;
SELECT NEXTVAL(sequence_name);
SELECT PREVIOUS VALUE FOR sequence_name;
SELECT LASTVAL(sequence_name);
SHOW CREATE SEQUENCE sequence_name;
SHOW CREATE TABLE sequence_name;
CREATE TABLE sequence-structure ... SEQUENCE=1
ALTER TABLE sequence RENAME TO sequence2;
RENAME TABLE sequence TO sequence2;
DROP [TEMPORARY] SEQUENCE [IF EXISTS] sequence_names
Missing features
- SETVAL(value,sequence_name), to be used with replication.
- Check replication, including checking that sequence tables are marked
not transactional.
- Check that a commit happens for NEXT VALUE that changes table data (may
already work)
- ALTER SEQUENCE. ANSI SQL version of setval.
- Share identical sequence entries to not add things twice to table list.
- testing insert/delete/update/truncate/load data
- Run and fix Alibaba sequence tests (part of mysql-test/suite/sql_sequence)
- Write documentation for NEXT VALUE / PREVIOUS_VALUE
- NEXTVAL in DEFAULT
- Ensure that NEXTVAL in DEFAULT uses database from base table
- Two NEXTVAL for same row should give same answer.
- Oracle syntax sequence_table.nextval, without any FOR or FROM.
- Sequence tables are treated as 'not read constant tables' by SELECT; Would
be better if we would have a separate list for sequence tables so that
select doesn't know about them, except if refereed to with FROM.
Other things done:
- Improved output for safemalloc backtrack
- frm_type_enum changed to Table_type
- Removed lex->is_view and replaced with lex->table_type. This allows
use to more easy check if item is view, sequence or table.
- Added table flag HA_CAN_TABLES_WITHOUT_ROLLBACK, needed for handlers
that want's to support sequences
- Added handler calls:
- engine_name(), to simplify getting engine name for partition and sequences
- update_first_row(), to be able to do efficient sequence implementations.
- Made binlog_log_row() global to be able to call it from ha_sequence.cc
- Added handler variable: row_already_logged, to be able to flag that the
changed row is already logging to replication log.
- Added CF_DB_CHANGE and CF_SCHEMA_CHANGE flags to simplify
deny_updates_if_read_only_option()
- Added sp_add_cfetch() to avoid new conflicts in sql_yacc.yy
- Moved code for add_table_options() out from sql_show.cc::show_create_table()
- Added String::append_longlong() and used it in sql_show.cc to simplify code.
- Added extra option to dd_frm_type() and ha_table_exists to indicate if
the table is a sequence. Needed by DROP SQUENCE to not drop a table.
Implementing cursor%ROWTYPE variables, according to the task description.
This patch includes a refactoring in how sp_instr_cpush and sp_instr_copen
work. This is needed to implement MDEV-10598 later easier, to allow variable
declarations go after cursor declarations (which is currently not allowed).
Before this patch, sp_instr_cpush worked as a Query_arena associated with
the cursor. sp_instr_copen::execute() switched to the sp_instr_cpush's
Query_arena when executing the cursor SELECT statement.
Now the Query_arena associated with the cursor is stored inside an instance
of a new class sp_lex_cursor (a LEX descendand) that contains the cursor SELECT
statement.
This simplifies the implementation, because:
- It's easier to follow the code when everything related to execution
of the cursor SELECT statement is stored inside the same sp_lex_cursor
object (rather than distributed between LEX and sp_instr_cpush).
- It's easier to link an sp_instr_cursor_copy_struct to
sp_lex_cursor rather than to sp_instr_cpush.
- Also, it allows to perform sp_instr_cursor_copy_struct::exec_core()
without having a pointer to sp_instr_cpush, using a pointer to sp_lex_cursor
instead. This will be important for MDEV-10598, because sp_instr_cpush will
happen *after* sp_instr_cursor_copy_struct.
After MDEV-10598 is done, this declaration:
DECLARE
CURSOR cur IS SELECT * FROM t1;
rec cur%ROWTYPE;
BEGIN
OPEN cur;
FETCH cur INTO rec;
CLOSE cur;
END;
will generate about this code:
+-----+--------------------------+
| Pos | Instruction |
+-----+--------------------------+
| 0 | cursor_copy_struct rec@0 | Points to sp_cursor_lex through m_lex_keeper
| 1 | set rec@0 NULL |
| 2 | cpush cur@0 | Points to sp_cursor_lex through m_lex_keeper
| 3 | copen cur@0 | Points to sp_cursor_lex through m_cursor
| 4 | cfetch cur@0 rec@0 |
| 5 | cclose cur@0 |
| 6 | cpop 1 |
+-----+--------------------------+
Notice, "cursor_copy_struct" and "set" will go before "cpush".
Instructions at positions 0, 2, 3 point to the same sp_cursor_lex instance.
