When there are E empty partitions left, auto-create N new empty
partitions for SYSTEM_TIME partitioning rotated by INTERVAL/LIMIT and
marked by AUTO_INCREMENT keyword. Syntax change: AUTO_INCREMENT
keyword (or shorter AUTO may be used instead) after LIMIT/INTERVAL
clause.
CREATE OR REPLACE TABLE t (x INT) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME LIMIT 100000 AUTO_INCREMENT;
CREATE OR REPLACE TABLE t (x INT) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME INTERVAL 1 WEEK AUTO_INCREMENT;
The current revision implements hard-coded values of 1 for E and N. As
well as auto-creation threshold MinInterval = 1 hour, MinLimit = 1000.
The name for newly added partition will be first chosen as "pX", where
X is partition number and "p" is hard-coded name prefix. If this name
is already occupied, the X will be incremented until the resulting
name will be free to use.
ALTER TABLE ADD PARTITION is now always fast. If there some history
partition overflow occurs manual ALTER TABLE REBUILD PARTITION is
needed.
* Explicit STARTS syntax
* SHOW CREATE
* Default STARTS rounding depending on INTERVAL type
* Warn when STARTS timestamp is later than query time
* Fix uninitialized Lex->create_last_non_select_table under
mysql_unpack_partition()
Default STARTS rounding depending on INTERVAL type
If STARTS clause is omitted, default one is assigned with value
derived from query timestamp. The rounding is done on STARTS value
depending on INTERVAL type:
SECOND: no rounding is done;
MINUTE: timestamp seconds is set to 0;
HOUR: timestamp seconds and minutes are set to 0;
DAY, WEEK, MONTH and YEAR: timestamp seconds, minutes and hours are
set to 0 (the date of rotation is kept as current date).
The code in convert_charset_partition_constant() did not
take into account that the call for item->safe_charset_converter()
can return NULL when conversion is not safe.
Note, 10.2 was not affected. The test for NULL presents in 10.2,
but it disappeared in 10.3 in a mistake. Restoring the test.
The old code to print partition values was too complicated:
- it created new Items for character set conversion purposes.
- it mixed string conversion and partition error reporting
in the same code blocks.
Simplifying the code as follows:
- Adding helper methods String::can_be_safely_convert_to() and
String::append_introducer_and_hex().
- Adding DBUG_EXECUTE_IF("generate_partition_syntax_for_frm", push_warning...)
into generate_partition_syntax_for_frm(), to test the PARTITON
clause written to FRM. Adding test partition_utf8-debug.test for this.
- Removing functions get_cs_converted_part_value_from_string() and
get_cs_converted_string_value. Changing get_partition_column_description()
to use Type_handler::partition_field_append_value() instead.
This makes SHOW CREATE TABLE and SELECT FROM I_S.PARTITIONS
use the same code path.
- Changing Type_handler::partition_field_append_value() not to
call convert_charset_partition_constant(), to avoid creating a new Item
for string conversion pursposes.
Rewritting the code to use only String methods.
- Removing error reporting code (ER_PARTITION_FUNCTION_IS_NOT_ALLOWED)
from Type_handler::partition_field_append_value().
The error is correctly detected and reported on the caller level.
So error reporting was redundant here.
Also:
- Moving methods Type_handler::partition_field_*() from sql_partition.cc
to sql_type.cc. This fixes compilation problem with -DPLUGIN_PARTITION=NO,
earlier introduced by the patch for MDEV-20831.
This clause in CREATE TABLE:
PARTITION BY LIST COLUMNS (inet6column)
(PARTITION p1 VALUES IN ('::'))
was erroneously written to frm file as:
PARTITION BY LIST COLUMNS(inet6column)
(PARTITION p1 VALUES IN (_binary 0x3A3A))
I.e. the text value '::' was converted to HEX representation
and prefixed with _binary.
A simple fix could write `_latin1 0x3A3A` instead of `_binary 0x3A3A`,
but in case of INET6 we don't need neither character set introducers,
nor HEX encoding, because text representation of INET6 values consist
of pure ASCII characters.
So this patch changes the above clause to be printed as:
PARTITION BY LIST COLUMNS(inet6column)
(PARTITION p1 VALUES IN ('::'))
Details:
The old code in check_part_field() was not friendly to pluggable data types.
Replacing this function to two new virtual methods in Type_handler:
virtual bool partition_field_check(const LEX_CSTRING &field_name,
Item *item_expr) const;
virtual bool partition_field_append_value(String *str,
Item *item_expr,
CHARSET_INFO *field_cs,
partition_value_print_mode_t mode)
const;
so data type plugins can decide whether they need to use character set
introducer and/or hex encoding when printing partition values.
InnoDB intentionally (it's a documented behavior) ignores changing of
DATA DIRECTORY and INDEX DIRECTORY for partitions. Though we should
issue warning when this happens.
Pruning fix for SYSTEM_TIME INTERVAL partitioning.
Allocating one more element in range_int_array for CURRENT partition
is required for RANGE pruning to work correctly
(get_partition_id_range_for_endpoint()).
SYSTEM_TYPE partitioning: COLUMN properties removed. Partitioning is
now pure RANGE based on UNIX_TIMESTAMP(row_end).
DECIMAL type is now allowed as RANGE partitioning, we can partition by
UNIX_TIMESTAMP() (but not for DATETIME which depends on local timezone
of course).
Fix partitioning for trx_id-versioned tables.
`partition by hash`, `range` and others now work.
`partition by system_time` is forbidden.
Currently we cannot use row_start and row_end in `partition by`, because
insertion of versioned field is done by engine's handler, as well as
row_start/row_end's value set up, which is a transaction id -- so it's
also forbidden.
The drawback is that it's now impossible to use `partition by key()`
without parameters for such tables, because it references row_start and
row_end implicitly.
* add handler::vers_can_native()
* drop Table_scope_and_contents_source_st::vers_native()
* drop partition_element::find_engine_flag as unused
* forbid versioning partitioning for trx_id as not supported
* adopt vers tests for trx_id partitioning
* forbid any row_end referencing in `partition by` clauses,
including implicit `by key()`
The problem described in the bug report happened because the code
did not test check_cols(1) after fix_fields() in a few places.
Additionally, fix_fields() could be called multiple times for SP variables,
because they are all fixed at a early stage in append_for_log().
Solution:
1. Adding a few helper methods
- fix_fields_if_needed()
- fix_fields_if_needed_for_scalar()
- fix_fields_if_needed_for_bool()
- fix_fields_if_needed_for_order_by()
and using it in many cases instead of fix_fields() where
the "fixed" status is not definitely known to be "false".
2. Adding DBUG_ASSERT(!fixed) into Item_splocal*::fix_fields()
to catch double execution.
3. Adding tests.
As a good side effect, the patch removes a lot of duplicate code (~60 lines):
if (!item->fixed &&
item->fix_fields(..) &&
item->check_cols(1))
return true;
rename to post_fix_fields_part_expr_processor()
because it's only used after fix_fields in
fix_fields_part_func() and can be used for
various post-fix_fields fixups
Don't use hidden system time in versioning,
but keep the system time logic in THD
to workaround low-res system clock and
replication not versioned to versioned.
This reverts MDEV-14788 (System versioning cannot
be based on local timestamps, as it is now).
Versioning is based on local timestamps again,
but timestamps are protected by MDEV-15923
(option to control who can set session @@timestamp).
