Problem:

Suppose there are two tables in the database related through a foreign key
constraint - the parent table and the child table.  Suppose there is an ALTER
TABLE on the child table which gets interrupted in such a way that the child
table is not available any more.

After crash recovery, an ALTER TABLE on the parent table identifies that its
foreign keys cannot be loaded.  This results in an error and a debug assert.

Solution:

Remove the debug assert and change error to a warning.

rb#8658 approved by Marko.

New added test case: alter_kill in innodb suite.

The server crashes on a SELECT because of space id mismatch. The
mismatch happens if the server crashes during an ALTER TABLE.

There are actually two cases of inconsistency, and three fixes needed
for the InnoDB problems.

We have dictionary data (tablespace or table name) in 3 places:

(a) The *.frm file is for the old table definition.
(b) The InnoDB data dictionary is for the new table definition.
(c) The file system did not rename the tablespace files yet.

In this fix, we will not care if the *.frm file is in sync with the
InnoDB data dictionary and file system. We will concentrate on the
mismatch between (b) and (c).

Two scenarios have been mentioned in this bug report. The simpler one
first:

1. The changes to SYS_TABLES were committed, and MLOG_FILE_RENAME2
records were written in a single mini-transaction commit.
The files were not yet renamed in the file system.
2a. The server is killed, without making a log checkpoint.
3a. The server refuses to start up, because replaying MLOG_FILE_RENAME2
fails.

I failed to repeat this myself. I repeated step 3a with a saved
dataset. The problem seems to be that MLOG_FILE_RENAME2 replay is
incorrectly being skipped when there is no page-redo log or
MLOG_FILE_NAME record for the old name of the tablespace.

FIX#1: Recover the id-to-name mapping also from MLOG_FILE_RENAME2
records when scanning the redo log. It is not necessary to write
MLOG_FILE_NAME records in addition to MLOG_FILE_RENAME2 records for
renaming tablespace files.

The scenario in the original Description involves a log checkpoint:
1. The changes to SYS_TABLES were committed, and MLOG_FILE_RENAME2
records were written in a single mini-transaction commit.
2. A log checkpoint and a server kill was injected.
3. Crash recovery will see no records (other than the MLOG_CHECKPOINT).
4. dict_check_tablespaces_and_store_max_id() will emit a message about
a non-found table #sql-ib22*.
5. A mismatch is triggering the assertion failure.

In my test, at step 4 the SYS_TABLES root page (0:8) contains these 3
records right before the page supremum:
* delete-marked (committed) name=#sql-ib21* record, with space=10.
* name=#sql-ib22*, space=9.
* name=t1, space=10.
space=10 is the rebuilt table (#sql-ib21*.ibd in the file system).
space=9 is the old table (t1.ibd in the file system).

The function dict_check_tablespaces_and_store_max_id() will enter
t1.ibd with space_id=10 into the fil_system cache without noticing
that t1.ibd contains space_id=9, because it invokes
fil_open_single_table_tablespace() with validate=false.

In MySQL 5.6, the space_id from all *.ibd files are being read when
the redo log checkpoint LSN disagrees with the FIL_PAGE_FILE_FLUSH_LSN
in the system tablespace. This field is only updated during a clean
shutdown, after performing the final log checkpoint.

FIX#2: dict_check_tablespaces_and_store_max_id() should pass
validate=true to fil_open_single_table_tablespace() when a non-clean
shutdown is detected, forcing the first page of each *.ibd file to be
read. (We do not want to slow down startup after a normal shutdown.)

With FIX#2, the SELECT would fail to find the table. This would
introduce a regression, because before WL#7142, a copy of the table
was accessible after recovery.

FIX#3: Maintain a list of MLOG_FILE_RENAME2 records that have been
written to the redo log, but not performed yet in the file system.
When performing a checkpoint, re-emit these records to the redo
log. In this way, a mismatch between (b) and (c) should be impossible.

fil_name_process(): Refactored from fil_name_parse(). Adds an item to
the id-to-filename mapping.

fil_name_parse(): Parses and applies a MLOG_FILE_NAME,
MLOG_FILE_DELETE or MLOG_FILE_RENAME2 record. This implements FIX#1.

fil_name_write_rename(): A wrapper function for writing
MLOG_FILE_RENAME2 records.

fil_op_replay_rename(): Apply MLOG_FILE_RENAME2 records. Replaces
fil_op_log_parse_or_replay(), whose logic was moved to fil_name_parse().

fil_tablespace_exists_in_mem(): Return fil_space_t* instead of bool.

dict_check_tablespaces_and_store_max_id(): Add the parameter
"validate" to implement FIX#2.

log_sys->append_on_checkpoint: Extra log records to append in case of
a checkpoint. Needed for FIX#3.

log_append_on_checkpoint(): New function, to update
log_sys->append_on_checkpoint.

mtr_write_log(): New function, to append mtr_buf_t to the redo log.

fil_names_clear(): Append the data from log_sys->append_on_checkpoint
if needed.

ha_innobase::commit_inplace_alter_table(): Add any MLOG_FILE_RENAME2
records to log_sys->append_on_checkpoint(), and remove them once the
files have been renamed in the file system.

mtr_buf_copy_t: A helper functor for copying a mini-transaction log.

rb#6282 approved by Jimmy Yang

In this issue we hit the assert because we are adding addition fields to the field JOIN::all_fields list. This
is done because  HEAP tables can't index BIT fields so  we need to use an additional hidden field for grouping because later it will be
converted to a LONG field. Original field will remain of the BIT type and will be returned. This happens when we convert DISTINCT to
GROUP BY.

The solution is to take into account the number of such hidden fields that would be added to the field
JOIN::all_fields list while calculating the size of the ref_pointer_array.

Problem was that verify_constraints() didn't check if
there was an error as part of evaluating constraints
(can happen in strict mode).

In one-row-insert the error was ignored when using
binary logging as binary logging clear errors if insert
succeeded. In multi-row-insert the error was noticed
for the second row.

After this fix one will get an error for both one and
multi-row inserts if the constraints generates a warning
in strict mode.

followup for 21bcfeb9

Part one, non-temporary tables.

Rrenaming a column can make destructive changes
to the TABLE. This TABLE cannot be used anymore
and needs to be reopened even if ALTER TABLE
was aborted with an error.

MDEV-14750 Valgrind Invalid read, ASAN heap-use-after-free in Item_ident::print upon SHOW CREATE on partitioned table

items in the partitioning function were taking
the table name from the table's field
(in set_field(from_field) in Item_field::fix_fields)
and field's table_name is TABLE::alias.

But alias is changed for every statement, and
can be realloced if next statement uses a longer
alias. But partitioning items are fixed once
and live as long as the TABLE does. So if
an alias is realloced, pointers to the old
alias string will become invalid.

Fix partitioning item table_name to point to
the actual table name instead.

rename to post_fix_fields_part_expr_processor()
because it's only used after fix_fields in
fix_fields_part_func() and can be used for
various post-fix_fields fixups

set the pointer to NULL to avoid double-free
when the item is cleaned up many times

(once in JOIN_TAB::cleanup(): tmp->jtbm_subselect->cleanup()
and once at the end of the query, with all other items)

in `ulonglong=ulong*uint` multiplication
is done in ulong, wrapping around on 32bit.

This became visible after C/C changed the
default charset to utf8, thus changing
mbmaxlem from 1 to 3.

RocksDB now supports "iterator bounds" which are min and max keys
that an iterator is interested in.

Iterator initialization function doesn't copy the keys, though, it keeps
pointers to them.
So if the buffer space for the keys is used for another iterator (the one
for checking for UNIUQE constraint violation in ha_rocksdb::ha_update_row)
then one can get incorrect query result.

Fixed by using a separate buffer for iterator bounds in the unique constraint
violation check.

This problem occured because the reorganization of the list of values when the
number of elements exceeds 32 was not handled correctly.  I have fixed the
problem by fixing the way that the list values are reorganized when the number
of list values exceeds 32.

Author:
  Jacob Mathew.

Reviewer:
  Alexey Botchkov.

Merged From:
  Commit 8e015986 on branch bb-10.3-MDEV-16101

This fix was initially missed, because there were multiple commits
with an empty message.

Merge a test case and a code change from MySQL 5.7.22.
There was no commit message, but a test case was included.
https://github.com/mysql/mysql-server/commit/d3ec326bcd8352fcd969dbfd54e5c604db9cd30b

There is no Bug 25899959 mentioned in the MySQL 8.0.11 history.
Based on the number, it should have been filed before August 2017.
Maybe it was initially fixed in a not-yet-public MySQL 9.0 branch?

The code change differs from MySQL 5.7, because the mbminmaxlen
were split in MariaDB in MDEV-7049.

MariaDB has a scaled-down version of the test so we need to set
@@rocksdb_max_row_locks lower to trigger the desired error

(didn't catch this on test BB run because this test is marked as "big")

Bloom filter is only used when reading the data from disk. If the data
happens to be still in the memtable, bloomfilter wont be used.

Stabilize the testcase by making sure the data is on disk before we
read it.

trx_purge_stop(): Release purge_sys->latch before attempting to
wake up the purge threads, so that they can actually wake up.
This is a regression of commit a13a636c
which attempted to fix MDEV-11802 by ensuring that srv_purge_wakeup()
will actually wait until all purge threads wake up.
Due to the purge_sys->latch, the threads might never wake up,
because some purge threads could end up waiting for purge_sys->latch
in trx_undo_prev_version_build() while holding dict_operation_lock
in shared mode. This in turn would block any DDL operations, the
InnoDB master thread, and InnoDB shutdown.

Down-scale the test by a factor of 2.

Backport the fix from the upstream and add our testcase.
Backported cset:
commit 997a979bf5e2f75ab88781d9d3fd22dddc1fc21f
Author: Manuel Ung <mung@fb.com>
Date:   Thu Feb 15 08:38:12 2018 -0800

    Fix crashes in autoincrement code paths

    Summary:
    There are two issues related to autoincrement that can lead to crashes:

    1. The max value for double/float type for autoincrement was not implemented in MyRocks, and can lead to assertions. The fix is to add them in.
    2. If we try to set auto_increment via alter table on a table without an auto_increment column defined, we segfault because there is no index from which to read the last value. The fix is to perform a check to see if autoincrement exists before reading from index (similar to code ha_rocksdb::open).

    Fixes https://github.com/facebook/mysql-5.6/issues/792
    Closes https://github.com/facebook/mysql-5.6/pull/794

    Differential Revision: D6995096

    Pulled By: lth

    fbshipit-source-id: 1130ce1

            failure upon SELECT with impossible condition

The problem appears because of a wrong implementation of the
Item_func_in::build_clone() method. It didn't clone 'array' and 'cmp_fields'
fields for the cloned IN predicate and this could cause crashes.
The Item_func_in::fix_length_and_dec() method was refactored and a new method
named Item_func_in::create_array() was created. It allowed to create 'array'
for cloned IN predicates in a proper way.

            work in the IN subqueries

The pushdown into the materialized derived table/view wasn't done because
optimize() for the derived was called before any conditions that can
be pushed down were extracted. So optimize() in
convert_join_subqueries_to_semijoins() method is called too early and is
unnecessary. The second optimize() call in mysql_handle_single_derived()
is enough.

In InnoDB, CREATE TEMPORARY TABLE does not allow FULLTEXT INDEX.
Replace a condition with a debug assertion, and add a test.

Problem:

Fix for Bug #21348684 (#Rb9581) introduced a conditional debug execute
'buf_pool_resize_chunk_null', which causes new chunks memory for 2nd
buffer pool instance is freed.

Buffer pool resize function removes all old chunks entry from
'buf_chunk_map_reg' and add new chunks entry into it. But when
'buf_pool_resize_chunk_null' is set true, 2nd buffer pool
instance's chunk entries are not added into 'buf_chunk_map_reg'.
When purge thread tries to access that buffer chunk, it leads to
debug assertion.

Fix:

Added old chunk entries into 'buf_chunk_map_reg' for 2nd buffer pool
instance when 'buf_pool_resize_chunk_null' debug condition is set to true.

Reviewed by: Jimmy <Jimmy.Yang@oracle.com>
RB: 18664

PROBLEM

Issue found during ntest run is a regression of  Bug #27141613. The
issue is basically when index is being freed due to an error during its
creation,when the index isn't added to dictionary cache its field
columns are not set, the derefrencing of null col pointer during the
clean of index from the virtual column's leads to a crash.

NOTE: Also test i_innodb.virtual_debug was failing on 32k page size and
above for the newly added scenario. Fixed that.

FIX

Added a check that if only the index is cached , the virtual index
freeing from the virtual cols index list is performed.

Reviewed by: Satya Bodapati<satya.bodapati@oracle.com>
RB: 18670

PROBLEM
=======
When add of virtual index fails with DB_TOO_BIG_RECORD , the virtual
index being freed isn't removed from the list of indexes a virtual
column(which is part of the index). This while the undo log is read
could fetch a wrong value during rollback and cause the assertion
reported in the bug particularly.

FIX
===
Added a function that is called when the virtual index being freed would
allow the index be removed from the index list of virtual column which
was a field of that index.

Reviwed By: Jimmy Yang<Jimmy.Yang@oracle.com>
RB: 18528

PROBLEM
-------

Whenever an fts table is created it registers itself in a queue which
is operated by a background thread whose job is to optimize the
fts tables in background. Additionally we place these fts tables in
non-LRU list so that they cannot be evicted from cache. But in the
scenario when a node is brought up which is already having fts
tables ,we first try to load the fts tables in dictionary ,but we skip
the part where it is added in background queue and in non-LRU list because
the background thread is not yet created,so these tables are loaded
but they can be evicted from the cache. Now coming to the deadlock scenario

1. A Server background thread is trying to evict a table from the cache
    because the cache is full,so it scans the LRU list for the tables it can
    evict.It finds the fts table (because of the reason explained above)
    can be evicted and it takes the dict_sys->mutex (this is a system wide mutex)
    submits a request to  the background thread to remove this table from queue
    and waits it to be completed.

2.  In the mean time fts_optimize_thread() is processing another job
    in the queue and needs dict_sys->mutex for a small amount of time,
    but it cannot get it because it is blocked by the first background thread.

So Thread 1 is waiting for its job to be completed by Thread 2,whereas Thread 2
is waiting for dict_sys->mutex held by thread 1 ,causing the deadlock.

FIX

Problem:

when incorrect value is assigned to innodb_data_file_path or
innodb_temp_data_file_path parameter, Innodb returns error and logs error
message in mysqlds.err file but there is no information in error message about
the parameter which causes Innodb initialization is failed.

Fix:

Added error message with parameter name and value, which causes Innodb
initialization is failed.

Reviewed by: Jimmy <Jimmy.Yang@oracle.com>
RB: 18206

Note: it does not appear to cover the bug fix! The test
will pass even if the Oracle Bug #26731689 fix is reverted.

Problem:

During ALTER, when filling stored column info, wrong column number is used.
This is because we ignored virtual column when iterating over columns in
table and lead to debug assertion.

Fix:

In InnoDB table cache object, vcols are on stored on one list, stored and
normal columns are stored in another list.
When looking for stored column, ignore the virtual columns to get the right
column number of stored column.

Reviewed by: Thiru <thirunarayanan.balathandayuth@oracle.com>,
             Satya <satya.bodapati@oracle.com>
RB: 17939