row_drop_table_for_mysql(): Avoid accessing non-existing dictionary tables.
dict_create_or_check_foreign_constraint_tables(): Add debug instrumentation
for creating and dropping a table before the creation of any non-core
dictionary tables.
trx_purge_add_update_undo_to_history(): Adjust a debug assertion, so that
it will not fail due to the test instrumentation.
The ONLY_FULL_GROUP_BY mode states that for SELECT ... GROUP BY queries,
disallow SELECTing columns which are not referred to in the GROUP BY clause,
unless they are passed to an aggregate function like COUNT() or MAX().
This holds only for the GROUP BY clause of the query.
The code also checks this for the partition clause of the window function which is
incorrect.
row_build_index_entry_low(): ext does not contain virtual columns.
row_upd_store_v_row(): Copy virtual column values
This is based on the following fix in MySQL 5.7.24:
commit 4ec2158bec73f1582501c4b3e3de250fed9edc9a
Author: Sachin Agarwal <sachin.z.agarwal@oracle.com>
Date: Fri Aug 24 14:44:13 2018 +0530
Bug #27968952 INNODB CRASH/CORRUPTION WITH TEXT PREFIX INDEXES
Problem:
There are two problems:
1. If there is one secondary index on extenally
stored column and another seconday index on virtual column (whose
base column is not externally stored). then while updating seconday
index on vitrual column, virtual column data is replaced by
externally stoared column.
2. In row update operation, node->row contains
shallow copy of virtual data fields. While building an update vector
containing all the fields to be modified, compute virtual column.
which may causes change in virtual data fields in node->row.
In both the above cases, while updating seconday index on virtual
column, couldn't find the row and hit an explicite assert inside
ROW_NOT_FOUND.
Fix:
1. Added check if column is virtual then its ext flag should be ZERO
and virtual column data will not be replaced by offset column data.
2. Deep copy of virtual data fields for node->row.
RB: #20382
Reviewed by : Jimmy.Yang@oracle.com
row_ins_check_foreign_constraint(): Do not overwrite hard errors
with the soft error DB_LOCK_WAIT. This prevents an infinite
wait loop when DB_INTERRUPTED was returned. For DB_LOCK_WAIT,
row_insert_for_mysql() would keep invoking row_ins_step() and the
transaction would remain active until the server shutdown is initiated.
The setting innodb_safe_truncate=ON reduces compatibility with older
versions of MariaDB and backup tools in two ways.
First, we will be writing TRX_UNDO_RENAME_TABLE records, which older
versions do not know about. These records could be misinterpreted if
a DDL transaction was recovered and would be rolled back.
Such rollback is only possible if the server was killed while
an incomplete DDL transaction was persisted. On transaction completion,
the insert_undo log pages would only be repurposed for new undo log
allocations, and their contents would not matter. So, older versions
will not have a problem with innodb_safe_truncate=ON if the server was
shut down cleanly.
Second, to prevent such recovery failure, innodb_safe_truncate=ON will
cause a modification of the redo log format identifier, which will
prevent older versions from starting up after a crash. MariaDB Server
versions older than 10.2.13 will refuse to start up altogether, even
after clean shutdown.
A server restart with innodb_safe_truncate=OFF will restore compatibility
with older server and backup versions.
When we have a query which has implicit_grouping then we are sure that we would end up with only one
row so there is no point to do DISTINCT computation
upon INSERT .. SELECT
The function Item *Item_direct_view_ref::derived_field_transformer_for_where()
erroneously did not strip off ref wrappers from references to materialized
derived tables / views. As a result the expressions that contained some
references of the type Item_direct_view_ref to columns of a materialized
derived table / view V were pushed into V incorrectly. This could cause
crashes for some INSERT ... SELECT statements.
A prepared backup from Mariabackup does not really need to contain any
redo log file, because all log will have been applied to the data files.
When the user copies a prepared backup to a data directory (overwriting
existing files), it could happen that the data directory already contained
redo log files from the past. mariabackup --copy-back) would delete the
old redo log files, but a user’s own copying script might not do that.
To prevent corruption caused by mixing an old redo log file with data
files from a backup, starting with MDEV-13311, Mariabackup would create
a zero-length ib_logfile0 that would prevent startup.
Actually, there is no need to prevent InnoDB from starting up when a
single zero-length file ib_logfile0 is present. Only if there exist
multiple data files of different lengths, then we should refuse to
start up due to inconsistency. A single zero-length ib_logfile0 should
be treated as if the log files were missing: create new log files
according to the configuration.
open_log_file(): Remove. There is no need to open the log files
at this point, because os_file_get_status() already determined
the size of the file.
innobase_start_or_create_for_mysql(): Move the creation of new
log files a little later, not when finding out that the first log
file does not exist, but after finding out that it does not exist
or it exists as a zero-length file.
Rename the 10.2-specific configuration option innodb_unsafe_truncate
to innodb_safe_truncate, and invert its value.
The default (for now) is innodb_safe_truncate=OFF, to avoid
disrupting users with an undo and redo log format change within
a Generally Available (GA) release series.
While MariaDB Server 10.2 is not really guaranteed to be compatible
with Percona XtraBackup 2.4 (for example, the MySQL 5.7 undo log format
change that could be present in XtraBackup, but was reverted from
MariaDB in MDEV-12289), we do not want to disrupt users who have
deployed xtrabackup and MariaDB Server 10.2 in their environments.
With this change, MariaDB 10.2 will continue to use the backup-unsafe
TRUNCATE TABLE code, so that neither the undo log nor the redo log
formats will change in an incompatible way.
Undo tablespace truncation will keep using the redo log only. Recovery
or backup with old code will fail to shrink the undo tablespace files,
but the contents will be recovered just fine.
In the MariaDB Server 10.2 series only, we introduce the configuration
parameter innodb_unsafe_truncate and make it ON by default. To allow
MariaDB Backup (mariabackup) to work properly with TRUNCATE TABLE
operations, use loose_innodb_unsafe_truncate=OFF.
MariaDB Server 10.3.10 and later releases will always use the
backup-safe TRUNCATE TABLE, and this parameter will not be
added there.
recv_recovery_rollback_active(): Skip row_mysql_drop_garbage_tables()
unless innodb_unsafe_truncate=OFF. It is too unsafe to drop orphan
tables if RENAME operations are not transactional within InnoDB.
LOG_HEADER_FORMAT_10_3: Replaces LOG_HEADER_FORMAT_CURRENT.
log_init(), log_group_file_header_flush(),
srv_prepare_to_delete_redo_log_files(),
innobase_start_or_create_for_mysql(): Choose the redo log format
and subformat based on the value of innodb_unsafe_truncate.
table for purge thread
Problem:
=======
Purge tries to fetch mdl lock for the whole table even though it tries
to open one of the partition. But table name length was wrongly set to indicate
the partition name too.
Solution:
========
- Table name length should identify the table name only not the partition name.
derived table / view by equality
Now rows of a materialized derived table are always put into a
temporary table before join operation. If BNLH is used to join this
table with the result of a partial join then both operands of the
join are actually put into main memory. In most cases this is not
efficient.
We could avoid this by sending the rows of the derived table directly
to the join operation. However this kind of data flow is not supported
yet.
Fixed by not allowing usage of hash join algorithm to join a materialized
derived table if it's joined by an equality predicate of the form
f=e where f is a field of the derived table.
derived table / view by equality
Now rows of a materialized derived table are always put into a
temporary table before join operation. If BNLH is used to join this
table with the result of a partial join then both operands of the
join are actually put into main memory. In most cases this is not
efficient.
We could avoid this by sending the rows of the derived table directly
to the join operation. However this kind of data flow is not supported
yet.
Fixed by not allowing usage of hash join algorithm to join a materialized
derived table if it's joined by an equality predicate of the form
f=e where f is a field of the derived table.
When converting table identifiers to a new format,
some tables can be renamed twice, which subsequently
leads to the appearance of "false" auxiliary tables
belonging to another main (parent) table (which does
not actually have auxiliary tables).
This is because the table number is repeatedly added
to the aux_tables_to_rename vector inside the function
fts_check_and_drop_orphaned_tables.
To correct this error, we must add a check for the
occurrence of the table number in the aux_tables_to_rename
vector before adding a new element.
https://jira.mariadb.org/browse/MDEV-16656
For the original test in 10.0 it was not really important if
find_user_wild() or find_user_exact() is used in sp_grant_privileges().
sp-security.test passed with either of them.
Fixing the test so it reliably fails with find_user_wild()
and pass with find_user_exact().
Simplify, and make it work with system tablespace outside of
innodb data home.
Also, do not reread TRX_SYS page in endless loop,
if it appears to be corrupted.
Use finite number of attempts.
if custom undo tablespace is defined
- In case of multiple undo tablespace, mariabackup have to open system
tablespace to find the list of undo tablespace present in TRX_SYS page.
For opening system tablespace, mariabackup should fetch the file name
from already initialized system tablespace object.
