Changing the return type of the following functions:
- CURRENT_TIMESTAMP, CURRENT_TIMESTAMP(), NOW()
- SYSDATE()
- FROM_UNIXTIME()
from DATETIME to TIMESTAMP.
Note, the old function NOW() returning DATETIME is still available
as LOCALTIMESTAMP or LOCALTIMESTAMP(), e.g.:
SELECT
LOCALTIMESTAMP, -- DATETIME
CURRENT_TIMESTAMP; -- TIMESTAMP
The change in the functions return data type fixes some problems
that occurred near a DST change:
- Problem #1
INSERT INTO t1 (timestamp_field) VALUES (CURRENT_TIMESTAMP);
INSERT INTO t1 (timestamp_field) VALUES (COALESCE(CURRENT_TIMESTAMP));
could result into two different values inserted.
- Problem #2
INSERT INTO t1 (timestamp_field) VALUES (FROM_UNIXTIME(1288477526));
INSERT INTO t1 (timestamp_field) VALUES (FROM_UNIXTIME(1288477526+3600));
could result into two equal TIMESTAMP values near a DST change.
Additional changes:
- FROM_UNIXTIME(0) now returns SQL NULL instead of '1970-01-01 00:00:00'
(assuming time_zone='+00:00')
- UNIX_TIMESTAMP('1970-01-01 00:00:00') now returns SQL NULL instead of 0
(assuming time_zone='+00:00'
These additional changes are needed for consistency with TIMESTAMP fields,
which cannot store '1970-01-01 00:00:00 +00:00'
The code erroneously called sec_since_epoch() for dates with zeros,
e.g. '2024-00-01'.
Fixi: adding a test that the date does not have zeros before
calling TIME_to_native().
Updated tests: cases with bugs or which cannot be run
with the cursor-protocol were excluded with
"--disable_cursor_protocol"/"--enable_cursor_protocol"
Fix for v.10.5
Changing the alias LOCALTIME->CURRENT_TIMESTAMP to LOCALTIME->CURRENT_TIME.
This changes the return type of LOCALTIME from DATETIME to TIME,
according to the SQL Standard.
This patch extends the timestamp from
2038-01-19 03:14:07.999999 to 2106-02-07 06:28:15.999999
for 64 bit hardware and OS where 'long' is 64 bits.
This is true for 64 bit Linux but not for Windows.
This is done by treating the 32 bit stored int as unsigned instead of
signed. This is safe as MariaDB has never accepted dates before the epoch
(1970).
The benefit of this approach that for normal timestamp the storage is
compatible with earlier version.
However for tables using system versioning we before stored a
timestamp with the year 2038 as the 'max timestamp', which is used to
detect current values. This patch stores the new 2106 year max value
as the max timestamp. This means that old tables using system
versioning needs to be updated with mariadb-upgrade when moving them
to 11.4. That will be done in a separate commit.
TIME-alike string and numeric arguments to TIMEDIFF()
can get additional fractional seconds during the supported
TIME range adjustment in get_time().
For example, during TIMEDIFF('839:00:00','00:00:00') evaluation
in Item_func_timediff::get_date(), the call for args[0]->get_time()
returns MYSQL_TIME '838:59:59.999999'.
Item_func_timediff::get_date() did not handle these extra digits
and returned a MYSQL_TIME result with fractional digits outside
of Item_func_timediff::decimals. This mismatch could further be
caught by a DBUG_ASSERT() in various other pieces of the code,
leading to a crash.
Fix:
In case if get_time() returned MYSQL_TIMESTAMP_TIME,
let's truncate all extra digits using my_time_trunc(&l_time,decimals).
This guarantees that the rest of the code returns a MYSQL_TIME
with second_part not conflicting with Item_func_timediff::decimals.
This patch adds for "--ps-protocol" second execution
of queries "SELECT".
Also in this patch it is added ability to disable/enable
(--disable_ps2_protocol/--enable_ps2_protocol) second
execution for "--ps-prototocol" in testcases.
Tests with checking metadata or that cannot be run with
the view-protocol are excluded from --view-protocol.
For tests that do not allow the use of an additional connection,
the util connection is disabled with "--disable_service_connection".
Also cases with bugs for --view-protocol are disabled.
Withing this task the following changes were made:
- Added sending of metadata info in prepare phase for the admin related
command (check table, checksum table, repair, optimize, analyze).
- Refactored implmentation of HELP command to support its execution in
PS mode
- Added support for execution of LOAD INTO and XA- related statements
in PS mode
- Modified mysqltest.cc to run statements in PS mode unconditionally
in case the option --ps-protocol is set. Formerly, only those statements
were executed using PS protocol that matched the hard-coded regular expression
- Fixed the following issues:
The statement
explain select (select 2)
executed in regular and PS mode produces different results:
MariaDB [test]> prepare stmt from "explain select (select 2)";
Query OK, 0 rows affected (0,000 sec)
Statement prepared
MariaDB [test]> execute stmt;
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| 1 | PRIMARY | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used |
| 2 | SUBQUERY | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
2 rows in set (0,000 sec)
MariaDB [test]> explain select (select 2);
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| 1 | SIMPLE | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
1 row in set, 1 warning (0,000 sec)
In case the statement
CREATE TABLE t1 SELECT * FROM (SELECT 1 AS a, (SELECT a+0)) a
is run in PS mode it fails with the error
ERROR 1054 (42S22): Unknown column 'a' in 'field list'.
- Uniform handling of read-only variables both in case the SET var=val
statement is executed as regular or prepared statememt.
- Fixed assertion firing on handling LOAD DATA statement for temporary tables
- Relaxed assert condition in the function lex_end_stage1() by adding
the commands SQLCOM_ALTER_EVENT, SQLCOM_CREATE_PACKAGE,
SQLCOM_CREATE_PACKAGE_BODY to a list of supported command
- Removed raising of the error ER_UNSUPPORTED_PS in the function
check_prepared_statement() for the ALTER VIEW command
- Added initialization of the data memember st_select_lex_unit::last_procedure
(assign NULL value) in the constructor
Without this change the test case main.ctype_utf8 fails with the following
report in case it is run with the optoin --ps-protocol.
mysqltest: At line 2278: query 'VALUES (_latin1 0xDF) UNION VALUES(_utf8'a' COLLATE utf8_bin)' failed: 2013: Lost connection
- The following bug reports were fixed:
MDEV-24460: Multiple rows result set returned from stored
routine over prepared statement binary protocol is
handled incorrectly
CONC-519: mariadb client library doesn't handle server_status and
warnign_count fields received in the packet
COM_STMT_EXECUTE_RESPONSE.
Reasons for these bug reports have the same nature and caused by
missing loop iteration on results sent by server in response to
COM_STMT_EXECUTE packet.
Enclosing of statements for processing of COM_STMT_EXECUTE response
in the construct like
do
{
...
} while (!mysql_stmt_next_result());
fixes the above mentioned bug reports.
Remove usage of deprecated variable storage_engine. It was deprecated in 5.5 but
it never issued a deprecation warning. Make it issue a warning in 10.5.1.
Replaced with default_storage_engine.
The MDEV-17262 commit 26432e49d3
was skipped. In Galera 4, the implementation would seem to require
changes to the streaming replication.
In the tests archive.rnd_pos main.profiling, disable_ps_protocol
for SHOW STATUS and SHOW PROFILE commands until MDEV-18974
has been fixed.
- 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'
