Fix an obvious typo: replace_column should be applied to SHOW TABLE STATUS,
not to SELECT * FROM t1.

Crash happened when deleting all columns that was part of a check constraint

The bug was that read map for from table was used when
checking CHECK constraint and was not properly reset
in copy_data_between_tables()

Step#1: RocksDB files require a special #define when they are compiled
with valgrind. Without that, valgrind fails with an 'unimplemented syscall'
error for fcntl call.

The failures with valgrind occur as a result of Spider sometimes using the
wrong transaction for operations in background threads that send requests to
the data nodes.  The use of the wrong transaction caused the networking to the
data nodes to use the wrong thread in some cases.  Valgrind eventually
detects this when such a thread is destroyed before it is used to disconnect
from the data node by that wrong transaction when it is freed.

I have fixed the problem by correcting the transaction used in each of these
cases.

Author:
  Jacob Mathew.

Reviewer:
  Kentoku Shiba.

Merged:
  Commit 4d576d9d on branch bb-10.3-MDEV-12900

MDEV-16153 Server crashes in Apc_target::disable, ASAN heap-use-after-free in Explain_query::~Explain_query upon/after EXECUTE IMMEDIATE

Explain_query must be created in the execution arena.
But JOIN::optimize_inner temporarily switches to the statement arena
under `if (sel->first_cond_optimization)`. This might cause
Explain_query to be allocated in the statement arena. Usually it is
harmless (although technically incorrect and a waste of memory), but
in case of EXECUTE IMMEDIATE, Prepared_statement object and its
statement arena are destroyed before log_slow_statement() call,
which uses Explain_query.

Fix:
1. Create Explain_query before switching arenas.
2. Before filling earlier-created Explain_query with data, set
thd->mem_root from the Explain_query::mem_root

Itcan happen that the connection is already gone during the window
between quering I_S.PROCESSLIST and KILL QUERY.

Fix is to tolerate ER_NO_SUCH_THREAD returned from KILL QUERY.

Add small improvement in message "Killing MDL query " to actually output
the query.
Also do not try to kill queries that are already in Killed state.

fix a typo that broke the main.view test

followup for ef295c31

Apply patch by Oleksandr Byelkin:
Do not use "only index read" in analyzing indices if there is a field which present in the index only partially.

Mark the plugin as dynamic-only.

It should work ok on all Unixes, but on Windows ,only worked by accident
in the past, with client not being Unicode safe.

It stopped working with Visual Studio 2017 15.7 update now.

The crash occurs when a thread that is closing its connection attempts to
access Spider transaction information when another thread has freed that memory
while processing Spider plugin deinit.  This occurs because Spider does not
adjust the plugin's reference count when it sets a transaction information
pointer for the plugin.

The fix I implemented changes the way Spider sets the transaction information
pointer to use thd_set_ha_data() so that Spider's plugin reference counter is
adjusted as well.

Author:
  Jacob Mathew.

Reviewer:
  Kentoku Shiba.

Merged From:
  Commit ab9d420d on branch 10.2

Fix two issues:
1. Rdb_ddl_manager::rename() loses the value of m_hidden_pk_val. new
object used to get 0, which means "not loaded from the db yet".

2. ha_rocksdb::load_hidden_pk_value() uses current transaction (and its
snapshot) when loading hidden PK value from disk. This may cause it to
load an out-of-date value.

The current code does not support recursive CTEs whose specifications
contain a mix of ALL UNION and DISTINCT UNION operations.
This patch catches such specifications and reports errors for them.

           with recursive subquery

There were two problems:
1. The code did not report that usage of global ORDER BY / LIMIT clauses
was not supported yet.
2. The code just reset fake_select_lex of the the unit specifying
a recursive CTE to NULL and that caused memory leaks in some cases.

The crash occurs when a thread that is closing its connection attempts to
access Spider transaction information when another thread has freed that memory
while processing Spider plugin deinit.  This occurs because Spider does not
adjust the plugin's reference count when it sets a transaction information
pointer for the plugin.

The fix I implemented changes the way Spider sets the transaction information
pointer to use thd_set_ha_data() so that Spider's plugin reference counter is
adjusted as well.

Author:
  Jacob Mathew.

Reviewer:
  Kentoku Shiba.

Merged From:
  Commit eabfadce on branch bb-10.3-MDEV-7914

When Item_insert_value needs a dummy field,
use zero-length Field_string, not Field_null.
The latter isn't compatible with CREATE ... SELECT.

jemalloc > 5.0.0 doesn't like to be linked with
a dlopen-ed module.

Don't link tokudb with jemalloc on Fedora 28,
LD_PRELOAD it instead with mysqld_safe
and with systemd.

Fixed by extending unique_table() with a flag to not allow usage of
the replaced table.

I also cleaned up find_dup_table() to not use goto next.
I also added more comments to the code in find_dup_table()

Analyze core independently of max-save-datadir and max-save-core setting.

Increment $num_saved_cores only if core was actually saved.

"Move any core files from e.g. mysqltest" independently of
max-save-datadir setting. Note: it may overwrite core from mysqld, which
might not be desired (it did work this way even before).

srv_purge_coordinator_thread(): Wait for all purge worker threads
to actually exit. An analysis of a core dump of a hung 10.3 server
revealed that one srv_worker_thread did not exit, even though the
purge coordinator had exited. This caused kill_server_thread and
mysqld_main to wait indefinitely. The main InnoDB shutdown was
never called, because unireg_end() was never called.

- Added missing test case for MyISAM

Imported the following test case from mysql to MariaDB

1) innodb.alter_kill
2) innodb.alter_foreign_crash
3) innodb.alter_rename_files
4) innodb.analyze_table
5) Appended the case in innodb-online-alter-gis

Problem:
We keep pinning pages in dict_stats_analyze_index_below_cur(),
but doesn't release these pages. When we have a relative small
buffer pool size, and big innodb_stats_persistent_sample_pages,
there will be no free pages for use.

Solution:
Use a separate mtr in dict_stats_analyze_index_below_cur(),
and commit mtr before return.
Reviewed-by: Jimmy Yang <jimmy.yang@oracle.com>
RB: 11362

In debug builds of MySQL, there is an configuration variable
that allows an InnoDB log checkpoint to be initiated:

SET GLOBAL innodb_log_checkpoint_now=ON;

Setting this variable while a table-rebuilding ALTER TABLE is executing
may result in an infinite loop.

checkpoint_now_set(): Account for log_sys->append_on_checkpoint->size().
Note that this function contains race conditions, because it is accessing
fields of log_sys without holding log_sys->mutex. We think that this is
acceptable, because this variable only exists for debugging purposes, in
debug builds of MySQL.

RB: 9947
Reviewed-by: Sunny Bains <sunny.bains@oracle.com>

to innodb.innodb-online-alter-gis

Problem:

The function row_build_index_entry_low() takes a dtuple_t object ('row') and
dict_index_t object ('index') as input and returns a new dtuple_t object
('entry') as output.  The dtuple_t object 'row' that is given as input might
have been constructed from a different dict_index_t object (!= index).  So
when accessing the externally stored data of the given 'row' we need to make
use of the correct index object.

Solution:

Store the page size information in the associated row_ext_t object.

rb#6086 approved by Vasil and Jimmy.

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.