* inject portion of time updates into mysql_delete main loop
* triggered case emits delete+insert, no updates
* PORTION OF `SYSTEM_TIME` is forbidden
* `DELETE HISTORY .. FOR PORTION OF ...` is forbidden as well
Optimized the code that removed multiple equalities pushed from HAVING
into WHERE. Now this removal is postponed until all multiple equalities
are eliminated in substitute_for_best_equal_field().
Condition can be pushed from the HAVING clause into the WHERE clause
if it depends only on the fields that are used in the GROUP BY list
or depends on the fields that are equal to grouping fields.
Aggregate functions can't be pushed down.
How the pushdown is performed on the example:
SELECT t1.a,MAX(t1.b)
FROM t1
GROUP BY t1.a
HAVING (t1.a>2) AND (MAX(c)>12);
=>
SELECT t1.a,MAX(t1.b)
FROM t1
WHERE (t1.a>2)
GROUP BY t1.a
HAVING (MAX(c)>12);
The implementation scheme:
1. Extract the most restrictive condition cond from the HAVING clause of
the select that depends only on the fields that are used in the GROUP BY
list of the select (directly or indirectly through equalities)
2. Save cond as a condition that can be pushed into the WHERE clause
of the select
3. Remove cond from the HAVING clause if it is possible
The optimization is implemented in the function
st_select_lex::pushdown_from_having_into_where().
New test file having_cond_pushdown.test is created.
1. Renaming Type_handler_json to Type_handler_json_longtext
There will be other JSON handlers soon, e.g. Type_handler_json_varchar.
2. Making the code more symmetric for data types:
- Adding a new virtual method
Type_handler::Column_definition_validate_check_constraint()
- Moving JSON-specific code from sql_yacc.yy to
Type_handler_json_longtext::Column_definition_validate_check_constraint()
3. Adding new files sql_type_json.cc and sql_type_json.h
and moving Type_handler+JSON related code into these files.
When creating a field of type JSON, it will be automatically
converted to TEXT with CHECK (json_valid(`a`)), if there wasn't any
previous check for the column.
Additional things:
- Added two bug fixes that was found while testing JSON. These bug
fixes has also been pushed to 10.3 (with a test case), but as they
where minimal and needed to get this task done and tested, the fixes
are repeated here.
- CREATE TABLE ... SELECT drops constraints for columns that
are both in the create and select part.
- If one has both a default expression and check constraint for a
column, one can get the error "Expression for field `a` is refering
to uninitialized field `a`.
- Removed some duplicate MYSQL_PLUGIN_IMPORT symbols
MDEV-17631 select_handler for a full query pushdown
Interfaces + Proof of Concept for federatedx with test cases.
The interfaces have been developed for integration of ColumnStore engine.
Calling st_select_lex::update_used_tables in JOIN::optimize_unflattened_subqueries
only when we are sure that the join have not been cleaned up.
This can happen for a case when we have a non-merged semi-join and an impossible
where which would lead to the cleanup of the join which has the non-merged semi-join
When we have a nested subquery then a subquery that was a dependent subquery
may change to an independent one when we optimizer the inner subqueries.
This is handled st_select_lex::optimize_unflattened_subqueries.
Currently a subquery that was changed to independent from dependent after optimization
phase incorrectly shows dependent in the output of Explain, this happens because we
don't update used_tables for the WHERE clause, ON clause, etc after the optimization phase.
MDEV-17660 sql_mode=ORACLE: Some keywords do not work as label names: history, system, versioning, without
MDEV-17661 Add sql_mode specific tokens for the keyword DECODE
main.derived_cond_pushdown: Move all 10.3 tests to the end,
trim trailing white space, and add an "End of 10.3 tests" marker.
Add --sorted_result to tests where the ordering is not deterministic.
main.win_percentile: Add --sorted_result to tests where the
ordering is no longer deterministic.
The test and also rpl_gtid_delete_domain failed on PPC64 platform
due to an incorrectly specified actual key for searching
in a gtid domain system hash. While the correct size is 32 bits
the supplied value was 8 bytes of long int size on the platform.
The problem became evident thanks to the big endiness which
cut off the *least* significant part of the value field.
Fixed with correcting a dynamic array initialization to hold
now uint32 values as well as the values extraction for
searching in the gtid domain system hash.
A new added test ensures no overflowed values are accepted
for deletion which prevents inadvertent action. Notice though
MariaDB [test]> set @@session.gtid_domain_id=(1 << 32) + 1;
MariaDB [test]> show warnings;
+---------+------+--------------------------------------------------------+
| Level | Code | Message |
+---------+------+--------------------------------------------------------+
| Warning | 1292 | Truncated incorrect gtid_domain_id value: '4294967297' |
+---------+------+--------------------------------------------------------+
MariaDB [test]> select @@session.gtid_domain_id;
+--------------------------+
| @@session.gtid_domain_id |
+--------------------------+
| 4294967295 |
+--------------------------+
This patch fills a serious flaw in the implementation of common table
expressions. Before this patch an attempt to prepare a statement from
a query with a parameter marker in a CTE that was used more than once
in the query ended up with a bogus error message. Similarly if a statement
in a stored procedure contained a CTE whose specification used a
local variables and this CTE was referred to more than once in the
statement then the server failed to execute the stored procedure returning
a bogus error message on a non-existing field.
The problems appeared due to incorrect handling of parameter markers /
local variables in CTEs that were referred more than once.
This patch fixes the problems by differentiating between the original
occurrences of a parameter marker / local variable used in the
specification of a CTE and the corresponding occurrences used
in copies of this specification. These copies are substituted
instead of non-first references to the CTE.
The idea of the fix and even some code were taken from the MySQL
implementation of the common table expressions.
a table value constructor shows wrong number of rows
This is another attempt to fix this bug. The previous patch did not take
into account that a transformation for ALL/ANY subqueries could be applied
to the materialized table that wrapped the table value constructor used as
a specification of the subselect used an ALL/ANY subquery. In this case
the result of the derived table used a sink of the class select_subselect
rather than of the class select_unit. Thus the previous fix could cause
memory overwrites when running EXPLAIN for queries with table value
constructors in ALL/ANY subselects.
