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().
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().
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.
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.
Problem was that user could drop streaming replication table
when streaming replication was used.
Fixed by not allowing user to drop streaming replication
table when galera is enabled. When it is not enabled
super can drop it (as any table in mysql database).
Added checks for wsrep_trx_fragment_unit and wsrep_trx_fragment_size
variables so that streaming replication can't be enabled
when streaming replication table does not exists.
Fixed also bug when user is trying to disable streaming
replication by wsrep_trx_fragment_size=0 when it was
not enabled.
Problem was executable comment in REPLACE that caused
consistency check that is not supported for RSU and
!InnoDB tables.
Fix is to check is Online Schema Upgrade (OSU) method
something else than TOI and if it is then table storage
engine must be InnoDB or error is produced and execution
returns and no consistency check is done.
don't reload stored routines in the middle of the execution
of a routine. we don't want different iterations of a loop
to see diffefent definitions
For this: remember Cversion in THD on the first sp cache lookup,
after that only compare versions with this value not with Cversion.
Relaxed check, only number of columns and the PK.
Enough to avoid crashes, but doesn't break upgrades and migration
from MySQL as in MDEV-37777.
Added checks everywhere. (flush/create/alter/drop server)
Check mysql.plugin table too.
The issue was that unpack_vcol_info_from_frm() wrongly linked the used
sequence tables into tables->internal_tables when more than one sequence
table was used.
Other things:
- Fixed internal_table_exists() to take db into account.
(This is making the code easier to read. As we where comparing
pointers the old code also worked).
See also MDEV-30046.
Idempotent write_row works same as REPLACE: if there is a duplicating
record in the table, then it will be deleted and re-inserted, with the
same update optimization.
The code in Rows:log_event::write_row was basically copy-pasted from
write_record.
What's done:
REPLACE operation was unified across replication and sql. It is now
representred as a Write_record class, that holds the whole state, and allows
re-using some resources in between the row writes.
Replace, IODKU and single insert implementations are split across different
methods, reluting in a much cleaner code.
The entry point is preserved as a single Write_record::write_record() call.
The implementation to call is chosen on the constructor stage.
This allowed several optimizations to be done:
1. The table key list is not iterated for every row. We find last unique key in
the order of checking once and preserve it across the rows. See last_uniq_key().
2. ib_handler::referenced_by_foreign_key acquires a global lock. This call was
done per row as well. Not all the table config that allows optimized replace is
folded into a single boolean field can_optimize. All the fields to check are
even stored in a single register on a 64-bit platform.
3. DUP_REPLACE and DUP_UPDATE cases now have one less level of indirection
4. modified_non_trans_tables is checked and set only when it's really needed.
5. Obsolete bitmap manipulations are removed.
Also:
* Unify replace initialization step across implementations:
add prepare_for_replace and finalize_replace
* alloca is removed in favor of mem_root allocation. This memory is reused
across the rows.
* An rpl-related callback is added to the replace branch, meaning that an extra
check is made per row replace even for the common case. It can be avoided with
templates if considered a problem.
Issue: When XA transaction is implicitly rolled back, we keep XA state
XA_ACTIVE and set rm_error to ER_LOCK_DEADLOCK. Other than XA command
we don't check for rm_error and DML and query are executed with a new
transaction.
Fix: One way to fix this issue is to set the XA state to XA_ROLLBACK_ONLY
which is checked while opening table open_tables() and ER_XAER_RMFAIL is
returned for any DML or Query.
Problem:
Empty queries are incremented if no rows are sent to the client in the
EXECUTE phase of select query. With cursor protocol, rows are not sent
during EXECUTE phase; they are sent later in FETCH phase. Hence,
queries executed with cursor protocol are always falsely treated as
empty in EXECUTE phase.
Fix:
For cursor protocol, empty queries are now counted during the FETCH
phase. This ensures counter correctly reflects whether any rows were
actually sent to the client.
Tests included in `mysql-test/main/show.test`.
check sequence privileges in Item_func_nextval::fix_fields(),
just like column privileges are checked in Item_field::fix_fields()
remove sequence specific hacks that kinda made sequence privilege
checks works, but not in all cases. And they were too lax,
didn't requre SELECT privilege for NEXTVAL. Also INSERT privilege looks
wrong here, UPDATE would've been more appropriate, but won't
change that for compatibility reasons.
also fixes
MDEV-36413 User without any privileges to a sequence can read from it and modify it via column default
Identifier names can be empty in the grammar. The check_ident_length
is used from everything from triggers, to partitions, to key names
and UDF names. This change updates 0 length identifiers as valid
without further checking.
Primary keys are one clear case where a empty name is used and
the name.str is a null pointer.
Checking empty names where the key->name.str is a null pointer
results in a UBSAN error in Well_formed_prefix_status further
down the stack which we can avoid.
DROP TABLE on child and UPDATE of parent table can cause an MDL BF-BF
conflict when applied concurrently.
DROP TABLE takes MDL locks on both child and its parent table, however
it only it did not add certification keys for the parent table.
This patch adds the following:
* Append certification keys corresponding to all parent tables
before DROP TABLE replication.
* Fix wsrep_append_fk_parent_table() so that it works when it is
given a table list containing temporary tables.
* Make sure function wsrep_append_fk_parent_table() is only called
for local transaction. That was not the case for ALTER TABLE.
* Add a test case that verifies that UPDATE parent depends on
preceeding DROP TABLE child.
* Adapt galera_ddl_fk_conflict test to work with DROP TABLE as well.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
The previous commit for fixing MDEV-35446 disabled setting
Galera errors on COM_STMT_PREPARE commands.
As a side effect, a number of tests were started to fail
due to the client receiving different error codes from the
ones expected in the test dependending on whether --ps-protocol
was used.
Also, in the case of test galera_ftwrl, it was found that
it is expected that during COM_STMT_PREPARE command, we
may perform a sync wait operation, which can fail with
LOCK_WAIT_TIMEOUT error.
The revised fix consists in anticipating the call to
wsrep_after_command_before_result(), so that we check for
BF aborts or errors during statement prepare, before sending
back the statement metadata message to client.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
Test failed sporadically when --ps-protocol was enabled:
a transaction that was BF aborted on COMMIT would succeed
instead of reporting the expected deadlock error.
The reason for the failure was that, depending on timing,
the transaction was BF aborted while the COMMIT statement
was being prepared through a COM_STMT_PREPARE command.
In the failing cases, the transaction was BF aborted
after COM_STMT_PREPARE had already disabled the diagnostics
area of the client. Attempt to override the deadlock error
towards the end of dispatch_command() would be skipped,
resulting in a successful COMMIT even if the transaction
is aborted.
This bug affected the following MTR tests:
- galera_insert_multi
- galera_nopk_unicode
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
