Fix various typos, in comments and DEBUG statements, and code changes
are non-functional.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.
As an additional improvement, let's store string representations of
the numbers using an array uint16[256] instead of char[512].
This allows to use int2store(), which copies two bytes at a time on x86,
instead of copying the two bytes with digits one-by-one.
This change gives an additional 7% to 26% query time reduce for:
SELECT BENCHMARK(10*1000*1000,CONCAT(TIME'10:20:30'));
SELECT BENCHMARK(10*1000*1000,CONCAT(TIME'10:20:30.123456'));
SELECT BENCHMARK(10*1000*1000,CONCAT(DATE'2001-01-01'));
SELECT BENCHMARK(10*1000*1000,CONCAT(TIMESTAMP'2001-01-01 10:20:30'));
SELECT BENCHMARK(10*1000*1000,CONCAT(TIMESTAMP'2001-01-01 10:20:30.123456'));
The total time reduce (part1 + part2) is now between 15% to 38%
for these queries.
This patch improves functions my_xxx_to_str() using the idea
introduced in this change in MySQL-8.0:
commit 8d10f2fff6bbdea7f436b868ebb5fd811defc68a
Author: Knut Anders Hatlen <knut.hatlen@oracle.com>
Date: Thu Oct 10 13:55:07 2019 +0200
Bug#30472888: IMPROVE THE PERFORMANCE OF INTEGER HANDLING IN THE TEXT PROTOCOL
The new way prints 2 digits at a time and demonstrates a very impressing query time reduce:
10% to 38%, depending on the exact data type and the number of fractional digits:
SELECT BENCHMARK(10*1000*1000,CONCAT(TIME'10:20:30'));
SELECT BENCHMARK(10*1000*1000,CONCAT(TIME'10:20:30.123456'));
SELECT BENCHMARK(10*1000*1000,CONCAT(DATE'2001-01-01'));
SELECT BENCHMARK(10*1000*1000,CONCAT(TIMESTAMP'2001-01-01 10:20:30'));
SELECT BENCHMARK(10*1000*1000,CONCAT(TIMESTAMP'2001-01-01 10:20:30.123456'));
See MDEV for details on the benchmark results.
The MDEV-20265 commit e746f451d5
introduces DBUG_ASSERT(right_op == r_tbl) in
st_select_lex::add_cross_joined_table(), and that assertion would
fail in several tests that exercise joins. That commit was skipped
in this merge, and a separate fix of MDEV-20265 will be necessary in 10.4.
For MDEV-15955, the fix in create_tmp_field_from_item() would cause a
compilation error. After a discussion with Alexander Barkov, the fix
was omitted and only the test case was kept.
In 10.3 and later, MDEV-15955 is fixed properly by overriding
create_tmp_field() in Item_func_user_var.
modified: ../sql-common/my_time.c
Moving the logic that mixes warnings of two kinds:
- those came from truncating garbage before the actual parsing of date/time
- those came during the actual parsing
from outside to inside of str_to_datetime_or_date_body().
This makes the caller code easier and removes some code duplication.
We'll be adding more parsing functions for time intervals soon,
so this change helps to avoid more duplicate code in the coming functions.
MDEV-17625 Different warnings when comparing a garbage to DATETIME vs TIME
- Splitting processes of data type conversion (to TIME/DATE,DATETIME)
and warning generation.
Warning are now only get collected during conversion (in an "int" variable),
and are pushed in the very end of conversion (not in parallel).
Warnings generated by the low level routines str_to_xxx() and number_to_xxx()
can now be changed at the end, when TIME_FUZZY_DATES is applied,
from "Invalid value" to "Truncated invalid value".
Now "Illegal value" is issued only when the low level routine returned
an error and TIME_FUZZY_DATES was not set. Otherwise, if the low level
routine returned "false" (success), or if NULL was converted to a zero
datetime by TIME_FUZZY_DATES, then "Truncated illegal value"
is issued. This gives better warnings.
- Methods Type_handler::Item_get_date() and
Type_handler::Item_func_hybrid_field_type_get_date() now only
convert and collect warning information, but do not push warnings.
- Changing the return data type for Type_handler::Item_get_date()
and Type_handler::Item_func_hybrid_field_type_get_date() from
"bool" to "void". The conversion result (success vs error) can be
checked by testing ltime->time_type. MYSQL_TIME_{NONE|ERROR}
mean mean error, other values mean success.
- Adding new wrapper methods Type_handler::Item_get_date_with_warn() and
Type_handler::Item_func_hybrid_field_type_get_date_with_warn()
to do conversion followed by raising warnings, and changing
the code to call new Type_handler::***_with_warn() methods.
- Adding a helper class Temporal::Status, a wrapper
for MYSQL_TIME_STATUS with automatic initialization.
- Adding a helper class Temporal::Warn, to collect warnings
but without actually raising them. Moving a part of ErrConv
into a separate class ErrBuff, and deriving both Temporal::Warn
and ErrConv from ErrBuff. The ErrBuff part of Temporal::Warn
is used to collect textual representation of the input data.
- Adding a helper class Temporal::Warn_push. It's used
to collect warning information during conversion, and
automatically pushes warnings to the diagnostics area
on its destructor time (in case of non-zero warning).
- Moving more code from various functions inside class Temporal.
- Adding more Temporal_hybrid constructors and
protected Temporal methods make_from_xxx(),
which convert and only collect warning information, but do not
actually raise warnings.
- Now the low level functions str_to_datetime() and str_to_time()
always set status->warning if the return value is "true" (error).
- Now the low level functions number_to_time() and number_to_datetime()
set the "*was_cut" argument if the return value is "true" (error).
- Adding a few DBUG_ASSERTs to make sure that str_to_xxx() and
number_to_xxx() always set warnings on error.
- Adding new warning flags MYSQL_TIME_WARN_EDOM and MYSQL_TIME_WARN_ZERO_DATE
for the code symmetry. Before this change there was a special
code path for (rc==true && was_cut==0) which was treated by
Field_temporal::store_invalid_with_warning as "zero date violation".
Now was_cut==0 always means that there are no any error/warnings/notes
to be raised, not matter what rc is.
- Using new Temporal_hybrid constructors in combination with
Temporal::Warn_push inside str_to_datetime_with_warn(),
double_to_datetime_with_warn(), int_to_datetime_with_warn(),
Field::get_date(), Item::get_date_from_string(), and a few other places.
- Removing methods Dec_ptr::to_datetime_with_warn(),
Year::to_time_with_warn(), my_decimal::to_datetime_with_warn(),
Dec_ptr::to_datetime_with_warn().
Fixing Sec6::to_time() and Sec6::to_datetime() to
convert and only collect warnings, without raising warnings.
Now warning raising functionality resides in Temporal::Warn_push.
- Adding classes Longlong_hybrid_null and Double_null, to
return both value and the "IS NULL" flag. Adding methods
Item::to_double_null(), to_longlong_hybrid_null(),
Item_func_hybrid_field_type::to_longlong_hybrid_null_op(),
Item_func_hybrid_field_type::to_double_null_op().
Removing separate classes VInt and VInt_op, as they
have been replaced by a single class Longlong_hybrid_null.
- Adding a helper method Temporal::type_name_by_timestamp_type(),
moving a part of make_truncated_value_warning() into it,
and reusing in Temporal::Warn::push_conversion_warnings().
- Removing Item::make_zero_date() and
Item_func_hybrid_field_type::make_zero_mysql_time().
They provided duplicate functionality.
Now this code resides in Temporal::make_fuzzy_date().
The latter is now called for all Item types when data type
conversion (to DATE/TIME/DATETIME) is involved, including
Item_field and Item_direct_view_ref.
This fixes MDEV-17563: Item_direct_view_ref now correctly converts
NULL to a zero date when TIME_FUZZY_DATES says so.
- Fixing portabibily problems in sql-common/my_time.c
(and additionally in sql/sql_time.cc)
- Re-enabling func_time.test
Now all new chunks added in MDEV-17351 work fine on all platforms.
Problems:
Functions LEAST() and GREATEST() in TIME context, as well as functions
TIMESTAMP(a,b) and ADDTIME(a,b), returned confusing results when the
input TIME-alike value in a number or in a string was out of the TIME
supported range.
In case of TIMESTAMP(a,b) and ADDTIME(a,b), the second argument
value could get extra unexpected digits. For example, in:
ADDTIME('2001-01-01 00:00:00', 10000000) or
ADDTIME('2001-01-01 00:00:00', '1000:00:00')
the second argument was converted to '838:59:59.999999'
with six fractional digits, which contradicted "decimals"
previously set to 0 in fix_length_and_dec().
These unexpected fractional digits led to confusing function results.
Changes:
1. GREATEST(), LEAST()
- fixing Item_func_min_max::get_time_native()
to respect "decimals" set by fix_length_and_dec().
If a value of some numeric or string time-alike argument
goes outside of the TIME range and gets limited to '838:59:59.999999',
it's now right-truncated to the correct fractional precision.
- fixing, Type_handler_temporal_result::Item_func_min_max_fix_attributes()
to take into account arguments' time_precision() or datetime_precision(),
rather than rely on "decimals" calculated by the generic implementation
in Type_handler::Item_func_min_max_fix_attributes(). This makes
GREATEST() and LEAST() return better data types, with the same
fractional precision with what TIMESTAMP(a,b) and ADDTIME(a,b) return
for the same arguments, and with DATE(a) and TIMESTAMP(a).
2. Item_func_add_time and Item_func_timestamp
It was semantically wrong to apply the limit of the TIME data type
to the argument "b", which plays the role of "INTERVAL DAY TO SECOND" here.
Changing the code to fetch the argument "b" as INTERVAL rather than as TIME.
The low level routine calc_time_diff() now gets the interval
value without limiting to '838:59:59.999999', so in these examples:
ADDTIME('2001-01-01 00:00:00', 10000000)
ADDTIME('2001-01-01 00:00:00', '1000:00:00')
calc_time_diff() gets '1000:00:00' as is. The SQL function result
now gets limited to the supported result data type range
(datetime or time) inside calc_time_diff(), which now calculates
the return value using the real fractional digits that
came directly from the arguments (without the effect of limiting
to the TIME range), so the result does not have any unexpected
fractional digits any more.
Detailed changes in TIMESTAMP() and ADDTIME():
- Adding a new class Interval_DDhhmmssff. It's similar to Time, but:
* does not try to parse datetime format, as it's not needed for
functions TIMESTAMP() and ADDTIME().
* does not cut values to '838:59:59.999999'
The maximum supported Interval_DDhhmmssff's hard limit is
'UINT_MAX32:59:59.999999'. The maximum used soft limit is:
- '87649415:59:59.999999' (in 'hh:mm:ss.ff' format)
- '3652058 23:59:59.999999' (in 'DD hh:mm:ss.ff' format)
which is a difference between:
- TIMESTAMP'0001-01-01 00:00:00' and
- TIMESTAMP'9999-12-31 23:59:59.999999'
(the minimum datetime that supports arithmetic, and the
maximum possible datetime value).
- Fixing get_date() methods in the classes related to functions
ADDTIME(a,b) and TIMESTAMP(a,b) to use the new class Interval_DDhhmmssff
for fetching data from the second argument, instead of get_date().
- Fixing fix_length_and_dec() methods in the classes related
to functions ADDTIME(a,b) and TIMESTAMP(a,b) to use
Interval_DDhhmmssff::fsp(item) instead of item->time_precision()
to get the fractional precision of the second argument correctly.
- Splitting the low level function str_to_time() into smaller pieces
to reuse the code. Adding a new function str_to_DDhhmmssff(), to
parse "INTERVAL DAY TO SECOND" values.
After these changes, functions TIMESTAMP() and ADDTIME()
return much more predictable results, in terms of fractional
digits, and in terms of the overall result.
The full ranges of DATETIME and TIME values are now covered by TIMESTAMP()
and ADDTIME(), so the following can now be calculated:
SELECT ADDTIME(TIMESTAMP'0001-01-01 00:00:00', '87649415:59:59.999999');
-> '9999-12-31 23:59:59.999999'
SELECT TIMESTAMP(DATE'0001-01-01', '87649415:59:59.999999')
-> '9999-12-31 23:59:59.999999'
SELECT ADDTIME(TIME'-838:59:59.999999', '1677:59:59.999998');
-> '838:59:59.999999'
Fixing C++ function check_date() to get the "fuzzydate" as
date_mode_t rather than ulonglong, so conversion from
date_time_t to ulonglong is now done inside C++ check_date(),
and no conversion is needed in the callers' code.
As an additional safety, modified the code not to pass
TIME_FUZZY_DATE to the low level C functions:
- check_date()
- str_to_datetime()
- str_to_time()
- number_to_datetime()
because TIME_FUZZY_DATE is known only on the C++ level,
C functions do not know it.
Soon we'll be adding more flags into the C++ level (i.e. to date_time_t),
e.g. for rounding. It's a good idea to prevent passing C++ specific
flags into pure C routines before this change.
Asserts were added into the affected C functions to verify
that the caller passed only known C level flags.
There were two problems related to the bug report:
1. Item_datetime::get_date() was not implemented.
So execution went through val_int() followed
by int-to-datetime or int-to-time conversion.
This was the reason why the optimizer did not
work well on data with fractional seconds.
2. Item_datetime::set() did not have a TIME specific code
to mix months and days to hours after unpack_time().
This is why the optimizer did not work well with negative
TIME values, as well as huge time values.
Changes:
1. Overriding Item_datetime::get_date(), to return ltime.
This fixes the problem N1.
2. Cleanup: Moving pack_time() and unpack_time() from
sql-common/my_time.c and include/my_time.h to
sql/sql_time.cc and sql/sql_time.h, as they are not needed
on the client side.
3. Adding a new "enum_mysql_timestamp_type ts_type" parameter
to unpack_time() and moving the TIME specific code to mix
months and days with hours inside unpack_time().
Adding a new "ts_type" parameter to Item_datetime::set(),
to pass it from the caller down to unpack_time().
So now the TIME specific code is automatically called
from Item_datetime::set(). This fixes the problem N2.
This change also helped to get rid of duplicate TIME specific code
from other three places, where mixing month/days to hours
was done immediately after unpack_time().
Moving the DATE specific code to zero hhmmssff
from Item_func_min_max::get_date_native to inside unpack_time(),
for symmetry.
4. Removing the virtual method in_vector::result_type(),
adding in_vector::type_handler() instead.
This helps to get result_type(), field_type(),
mysql_timestamp_type() of an in_vector easier.
Passing type_handler()->mysql_timestamp_type() as
a new parameter to Item_datetime::set() inside
in_temporal::value_to_item().
5. Cleaup: Removing separate implementations of in_datetime::get_value()
and in_time::get_value(). Adding a single implementation
in_temporal::get_value() instead.
Passing type_handler()->field_type() to get_value_internal().
Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.
This fix excludes rocksdb, spider,spider, sphinx and connect for now.
- Added sql/mariadb.h file that should be included first by files in sql
directory, if sql_plugin.h is not used (sql_plugin.h adds SHOW variables
that must be done before my_global.h is included)
- Removed a lot of include my_global.h from include files
- Removed include's of some files that my_global.h automatically includes
- Removed duplicated include's of my_sys.h
- Replaced include my_config.h with my_global.h
Define my_thread_id as an unsigned type, to avoid mismatch with
ulonglong. Change some parameters to this type.
Use size_t in a few more places.
Declare many flag constants as unsigned to avoid sign mismatch
when shifting bits or applying the unary ~ operator.
When applying the unary ~ operator to enum constants, explictly
cast the result to an unsigned type, because enum constants can
be treated as signed.
In InnoDB, change the source code line number parameters from
ulint to unsigned type. Also, make some InnoDB functions return
a narrower type (unsigned or uint32_t instead of ulint;
bool instead of ibool).
MDEV-6099 Bad results for DATE_ADD(.., INTERVAL 2000000000000000000.0 SECOND)
MDEV-6097 Inconsistent results for CAST(int,decimal,double AS DATETIME)
MDEV-6100 No warning on CAST(9000000 AS TIME)
