SQLCOM_REVOKE_ALL needs it because SQLCOM_REVOKE does.
SQLCOM_DROP_ROLE needs it because SQLCOM_DROP_USER does.
SQLCOM_CREATE_SERVER / SQLCOM_ALTER_SERVER / SQLCOM_DROP_SERVER
need it because SQLCOM_CREATE_USER / etc do.
introduce a dedicated enum type for sql_command_flags
to simplify debugging:
(gdb) p sql_command_flags[SQLCOM_SELECT]
$2 = (CF_REEXECUTION_FRAGILE | CF_CAN_GENERATE_ROW_EVENTS | CF_PREOPEN_TMP_TABLES | CF_CAN_BE_EXPLAINED | CF_OPTIMIZER_TRACE)
This patch implements support for implicit query block (QB) names in
optimizer hints, allowing hints to reference query blocks and tables
within derived tables, views and CTEs without requiring explicit
QB_NAME hints.
Examples.
-- Addressing a table inside a derived table using implicit QB name
select /*+ no_index(t1@dt) */ *
from (select * from t1 where a > 10) as DT;
-- this is an equivalent to:
select /*+ no_index(t1@dt) */ * from
(select /*+ qb_name(dt)*/ * from t1 where a > 10) as DT;
-- Addressing a query block corresponding to the derived table
select /*+ no_bnl(@dt) */ *
from (select * from t1, t2 where t.1.a > t2.a) as DT;
-- View
create view v1 as select * from t1 where a > 10 and b > 100;
-- referencing a table inside a view by implicit QB name:
select /*+ index_merge(t1@v1 idx_a, idx_b) */ *
from v1, t2 where v1.a = t2.a;
-- equivalent to:
create view v1 as select /*+ qb_name(qb_v1) */ *
from t1 where a > 10 and b > 100;
select /*+ index_merge(t1@qb_v1 idx_a, idx_b) */ *
from v1, t2 where v1.a = t2.a;
-- CTE
with aless100 as (select a from t1 where b <100)
select /*+ index(t1@aless100) */ * from aless100;
-- equivalent to:
with aless100 as (select /*+ qb_name(aless100) */ a from t1 where b <100)
select /*+ index(t1@aless100) */ * from aless100;
Limitations:
- Only SELECT statements support implicit QB names. DML operations
(UPDATE, DELETE, INSERT) only support explicit QB names
Originally two MDL_EXCLUSIVE are used for pure alias of derived table
and its schema which is empty db name. It is concurrency performance
overhead and there is no obvious reason why such MDL should exist.
MDEV-33985 changed pure alias check from `db.str` to `db.length` and
that allowed `empty_c_string` to be pure alias too. It is important
for MDEV-33985 fix with sequences. Now such kind of pure alias skips
MDL initialization and thus derived table fails falsely on BACKUP
namespace as it is default namespace for 0-filled structure (see TODO
comments).
The fix a) keeps MDL_NOT_INITIALIZED for uninitialized MDL and that
was the consequence of MDL_INTENTION_EXCLUSIVE value 0 (see TODO
comment).
And b) does not update MDL type for pure alias when view is
initialized, so it is MDL_NOT_INITIALIZED. `lock_table_names()` code
naturally skips such kind of MDL with (mdl_request.type <
MDL_SHARED_UPGRADABLE) condition when processing tables list.
Optimization in st_select_lex_unit::prepare() removes ORDER BY for
certain subqueries. That excludes ORDER BY items from being fixed, but
sl->window_funcs still contains window function items and those
related to optimized out ORDER BY are unfixed. The error about missing
window spec is thrown when the item is fixed. Hence we get redundant
processing of window function items without checking window spec
existence.
The fix removes the related window function items when ORDER BY is
optimized out. ORDER accumulates window_funcs at parser stage which
are then removed from SELECT_LEX::window_funcs. The fix also updates
similar optimization in mysql_make_view().
SHOW CREATE SERVER was accessible to any user with a global
privilege, without requiring FEDERATED ADMIN. Add a privilege
check before mysql_show_create_server() so that only users
with FEDERATED ADMIN can view server definitions.
removed:
* DES encryption
* --secure-auth
* --old
* spider table options: bfz, btt, cmd, ctp, cwg, isa, ilm, ios, smd, stc, stl
extended under old-mode:
* YEAR(2), still available when old-mode=2_DIGIT_YEAR
un-deprecated:
* keep_files_on_create, originally (MDEV-23570) the idea was to make it
TRUE and deprecate. It cannot be removed when FALSE, but TRUE breaks
mariabackup.aria_backup where a table is altered from Aria to InnoDB
during a backup, so both t.MAD/t.MAI and t.ibd gets into a backup.
* rename to follow the standard vprintf name convention
* remove `(LEX_CSTRING*) &lex_string` casts
* remove some redundant casts too
* LEX_CSTRING -> Lex_ident_db in path
* Hash_set<Sroutine_hash_entry>
* move assert out of the loop
* some comments and whitespace changes
Definition
==========
Implement the SET PATH statement.
```
SET PATH 'schema1, schema2, schema3';
```
Function
--------
In MariaDB, the SQL-path will also be used to lookup packages in
package routine invocations, so the following script:
SET PATH 'sys';
SELECT UTL_ENCODE.BASE64_DECODE('data');
invokes SYS.UTL_ENCODE.BASE64_DECODE('data'), i.e. the function
BASE64_DECODE() in the packge UTL_ENCODE in the database SYS
(if such package and package routine exist).
MariaDB implementation details
------------------------------
The ticket's requirement stated the grammar should support delimited
identifiers with backticks or double quotes within the string quote,
ie: the single tick. A simple parser was implemented to handle this
requirement in Sql_path::from_text.
Only 16 schemas are supported per session - we do not want too many
schemas in the path anyway since it will impact performance. This also
means that the path cache is a simple static array for easier memory
management.
The bug was that thd->lex->limit_rows_examined_cnt was not reset after
queries. It is reset in lex_start() at the start of the next query
execution.
This causes general_log_write(), which is called before lex_start(), to
exceed the limit. The effect is a crash or the next query would not be
executed.
Fixed by resetting limit_rows_examined_cnt at end of query.
Pure aliases are not handled properly by Item_func_nextval::val_int().
add_table_to_list() does not create MDL request for pure aliases,
i.e. when there is no table_list->db set or TL_OPTION_ALIAS was
set. When the expression is not inside CTE the case with empty db is
handled by:
else if (!lex->with_cte_resolution && lex->copy_db_to(&db))
DBUG_RETURN(0);
So, table_list gets current database name and the query is failed with
ER_NO_SUCH_TABLE error.
The fix adds the case of is_pure_alias() for
Item_func_nextval::val_int() and fails it with ER_NOT_SEQUENCE2 error.
Note: semantics for TL_OPTION_ALIAS cannot be based on empty db, only
parser can set TL_OPTION_ALIAS as resolve_references_to_cte() relies
on TL_OPTION_ALIAS after copy_db_to().
Implement an improved binlog implementation that is integrated into
the storage engine. The new implementation is enabled with the
--binlog-storage-engine option. Initially the InnoDB storage engine
implements the binlog.
Integrating the binlog in the storage engine improves performance,
since it makes the InnoDB redo log the single source of truth and
avoids the need for expensive two-phase commit between binlog and
engine. It also makes it possible to disable durability (set
--innodb-flush-log-at-trx-commit=0) to further improve performance,
while still preserving the ability to recover the binlog and database
into a consistent state after a crash.
The new binlog implementation also greatly improves the internal
design and implementation of the binlog, and enables future
enhancements for replication.
This is a squash of the original 11.4-based patch series.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Routine name resolution performed on a temporary memory root
during execution. So on the second execution LEX::spname members
pointed to a cleared memory.
Fixing to peform the resolution to parse time, like the CALL statement does.
During the execution time LEX::spname members now stay untouched.
We extend from the SQL standard to match the functionality of other
databases that allow the inclusion of a CTE definition prior to update
and delete statements.
These CTEs are currently read only, like other derived tables, so
cannot have their columns updated in updates set clause, nor have rows
removed in the delete statement.
Approved by: Oleksandr Byelkin (sanja@mariadb.com)
Problem was that wrong level of Sql_condition was used on
push_warning_printf and error handling of REFRESH_HOSTS
(and similar) was broken.
Fixed warning printing in wsrep_TOI_begin after enter_toi_local
is called. Fixed also error handling after REFRESH_HOSTS (and others)
if TOI begin failed.
Fixed by setting server_status SERVER_STATUS_RETURNED_ROW if send_data
is called for stored procedures.
This make the definition of Empty_queries well defined:
"Empty_queries" is the number of SELECT queries that returns 0 rows.
