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.
it's not enough to look for NOT NULL IS, this also fails queries like
SELECT NOT NULL <=> NULL;
and adds no value anymore, as the grammar now requires parentheses
- Force usage of () around complex DEFAULT expressions
- Give error if DEFAULT expression contains invalid characters
- Don't use const_charset_conversion for stored Item_func_sysconf expressions
as the result is not constaint over different executions
- Fixed Item_func_user() to not store calculated value in str_value
MDEV-10134 Add full support for DEFAULT
- Added support for using tables with MySQL 5.7 virtual fields,
including MySQL 5.7 syntax
- Better error messages also for old cases
- CREATE ... SELECT now also updates timestamp columns
- Blob can now have default values
- Added new system variable "check_constraint_checks", to turn of
CHECK constraint checking if needed.
- Removed some engine independent tests in suite vcol to only test myisam
- Moved some tests from 'include' to 't'. Should some day be done for all tests.
- FRM version increased to 11 if one uses virtual fields or constraints
- Changed to use a bitmap to check if a field has got a value, instead of
setting HAS_EXPLICIT_VALUE bit in field flags
- Expressions can now be up to 65K in total
- Ensure we are not refering to uninitialized fields when handling virtual fields or defaults
- Changed check_vcol_func_processor() to return a bitmap of used types
- Had to change some functions that calculated cached value in fix_fields to do
this in val() or getdate() instead.
- store_now_in_TIME() now takes a THD argument
- fill_record() now updates default values
- Add a lookahead for NOT NULL, to be able to handle DEFAULT 1+1 NOT NULL
- Automatically generate a name for constraints that doesn't have a name
- Added support for ALTER TABLE DROP CONSTRAINT
- Ensure that partition functions register virtual fields used. This fixes
some bugs when using virtual fields in a partitioning function
Added the check whether there are set functions in the specifications of recursive CTE.
Added the check whether there are recursive references in subqueries.
Introduced boolean system variable 'standards_compliant_cte'. By default it's set to 'on'.
When it's set to 'off' non-standard compliant CTE can be executed.
When the specification of a WITH table referred to a view
that used a based table with the same name as the WITH table
the server went into an infinite loop because it erroneously
resolved the reference to the base table as the reference to
the WITH table.
With tables used in a view cannot be searched for beyond the
scope the view.
