Make st_select_lex::set_explain_type() take into account that JOIN_TABs
it is traversing may be also post-join aggregation JOIN_TABs (which
have pos_in_table_list=NULL, etc).
This patch fills in a serious flaw in the
code that supports condition pushdown into
materialized views / derived tables.
If a predicate happened to contain a reference
to a mergeable view / derived table and it does
not depended directly on the target materialized
view / derived table then the predicate was not
considered as a subject to pusdown to this view
/ derived table.
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.
Do not silence uncertain cases, or fix any bugs.
The only functional change should be that ha_federated::extra()
is not calling DBUG_PRINT to report an unhandled case for
HA_EXTRA_PREPARE_FOR_DROP.
Do not silence uncertain cases, or fix any bugs.
The only functional change should be that ha_federated::extra()
is not calling DBUG_PRINT to report an unhandled case for
HA_EXTRA_PREPARE_FOR_DROP.
At some conditions the function opt_sum_query() can apply MIN/MAX
optimizations to to Item_sum objects of a select These optimizations
becomes invalid if this select is the subquery of an IN subquery
predicate that is converted to a EXISTS subquery. Thus in this case
the MIX/MAX optimizations that have been applied in opt_sum_query()
must be rolled back.
This bug appeared in 5.3 when the code for the cost base choice between
materialization and in-to-exists transformation of non-correlated
IN subqueries was introduced. Before this code in-to-exists
transformations were always performed before the call of opt_sum_query().
Cherry-pick: f4a0af070ce49abae60040f6f32e1074309c27fb
Author: Dmitry Lenev <dmitry.lenev@oracle.com>
Date: Mon Jul 25 16:06:52 2016 +0300
Fix for bug #16672723 "CAN'T FIND TEMPORARY TABLE".
Attempt to execute prepared CREATE TABLE SELECT statement which used
temporary table in the subquery in FROM clause and stored function
failed with unwarranted ER_NO_SUCH_TABLE error. The same happened
when such statement was used in stored procedure and this procedure
was re-executed.
The problem occurred because execution of such prepared statement/its
re-execution as part of stored procedure incorrectly set
Query_table_list::query_tables_own_last marker, indicating the last
table which is directly used by statement. As result temporary table
used in the subquery was treated as indirectly used/belonging to
prelocking list and was not pre-opened by open_temporary_tables()
call before statement execution. Thus causing ER_NO_SUCH_TABLE errors
since our code assumes that temporary tables need to be correctly
pre-opened before statement execution.
This problem became visible only in version 5.6 after patches related to
bug 11746602/27480 "EXTEND CREATE TEMPORARY TABLES PRIVILEGE TO ALLOW
TEMP TABLE OPERATIONS" since they have introduced pre-opening of temporary
tables for statements.
Incorrect setting of Query_table_list::query_tables_own_last happened
in LEX::first_lists_tables_same() method which is called by CREATE TABLE
SELECT implementation as part of LEX::unlink_first_table(), which temporary
excludes table list element for table being created from the query table
list before handling SELECT part.
LEX::first_lists_tables_same() tries to ensure that global table list of
the statement starts with the first table list element from the first
statement select. To do this it moves such table list element to the head
of the global table list. If this table happens to be last directly-used
table for the statement, query_tables_own_last marker is pointing to it.
Since this marker was not updated when table list element was moved we
ended up with all tables except the first table separated by it as if
they were not directly used by statement (i.e. belonged to prelocked
tables list).
This fix changes code of LEX::first_lists_tables_same() to update
query_tables_own_last marker in cases when it points to the table
being moved. It is set to the table which precedes table being moved
in this case.
partitioning was setting subj as a partitioning-specific
hack (GET_FIXED_FIELDS_FLAG field flag to detect partitioning fields)
inside init_lex_with_single_table(). But vcols also use
init_lex_with_single_table(), they run fix_fields()
in open_table_from_share() before partitioning and this messes up
partitioning GET_FIXED_FIELDS_FLAG logic.
multi-update was setting up read_set/vcol_set in
multi_update::initialize_tables() that is invoked after
the optimizer (JOIN::optimize_inner()). But some rows - if they're from
const tables - will be read already in the optimizer, and these rows
will not have all necessary column/vcol values.
* multi_update::initialize_tables() uses results from the optimizer
and cannot be moved to be called earlier.
* multi_update::prepare() is called before the optimizer, but
it cannot set up read_set/vcol_set, because the optimizer
might reset them (see SELECT_LEX::update_used_tables()).
As a fix I've added a new method, select_result::prepare_to_read_rows(),
it's called from inside the optimizer just before make_join_statistics().
This is similar to MysQL Worklog 3253, but with
a different implementation. The disk format and
SQL syntax is identical with MySQL 5.7.
Fetures supported:
- "Any" ammount of any trigger
- Supports FOLLOWS and PRECEDES to be
able to put triggers in a certain execution order.
Implementation details:
- Class Trigger added to hold information about a trigger.
Before this trigger information was stored in a set of lists in
Table_triggers_list and in Table_triggers_list::bodies
- Each Trigger has a next field that poinst to the next Trigger with the
same action and time.
- When accessing a trigger, we now always access all linked triggers
- The list are now only used to load and save trigger files.
- MySQL trigger test case (trigger_wl3253) added and we execute these
identically.
- Even more gracefully handling of wrong trigger files than before. This
is useful if a trigger file uses functions or syntax not provided by
the server.
- Each trigger now has a "Created" field that shows when the trigger was
created, with 2 decimals.
Other comments:
- Many of the changes in test files was done because of the new "Created"
field in the trigger file. This shows up in SHOW ... TRIGGER and when
using information_schema.trigger.
- Don't check if all memory is released if on uses --gdb; This is needed
to be able to get a list from safemalloc of not freed memory while
debugging.
- Added option to trim_whitespace() to know how many prefix characters
was skipped.
- Changed a few ulonglong sql_mode to sql_mode_t, to find some wrong usage
of sql_mode.
The condition pushed into WHERE/HAVING of a materialized
view/derived table may differ for different executions of
the same prepared statement. That's why the should be
ANDed with the existing WHERE/HAVING conditions only after all
permanent transformations of these conditions has been
performed.
Make the new (CTE-related) code in set_explain_type to take into
account that some JOIN_TABs are non-merged semi-joins, and do not
have a TABLE object.
- Tabular EXPLAIN now prints "RECURSIVE UNION".
- There is a basic implementation of EXPLAIN FORMAT=JSON.
- it produces "recursive_union" JSON struct
- No other details or ANALYZE support, yet.
Temporary tables created for recursive CTE
were instantiated at the prepare phase. As
a result these temporary tables missed
indexes for look-ups and optimizer could not
use them.
