When performing a hash search via HASH_SEARCH we first look at a key of a node
and then at its pointer to the next node in chain. If we have those in one cache
line instead of a two we reduce memory reads.

I found dict_table_t, fil_space_t and buf_page_t suitable for such improvement.

MDEV-16499 ER_NO_SUCH_TABLE_IN_ENGINE followed by "Please drop the table and recreate" upon adding FULLTEXT key to table with virtual column

When we have a nested subquery then a subquery that was a dependent subquery
may change to an independent one when we optimizer the inner subqueries.
This is handled st_select_lex::optimize_unflattened_subqueries.
Currently a subquery that was changed to independent from dependent after optimization
phase incorrectly shows dependent in the output of Explain, this happens because we
don't update used_tables for the WHERE clause, ON clause, etc after the optimization phase.

This is a regression after MDEV-13671.

The bug is related to key part prefix lengths wich are stored in SYS_FIELDS.
Storage format is not obvious and was handled incorrectly which led to data
dictionary corruption.

SYS_FIELDS.POS actually contains prefix length too in case if any key part
has prefix length.

innobase_rename_column_try(): fixed prefixes handling

Tests for prefixed indexes added too.

Closes #1063

This fixes a regression that was introduced in MySQL 5.6.6
in an error handling code path, in the following change:

commit 024f363d6b5f09b20d1bba411af55be95c7398d3
Author: kevin.lewis@oracle.com <>
Date:   Fri Jun 15 09:01:42 2012 -0500

    Bug #14169459 INNODB; DROP TABLE DOES NOT DELETE THE IBD FILE
    FOR A TEMPORARY TABLE.

Relevant if exists flag are added for create database and drop database.

Create a new constant MAX_DATA_LENGTH_FOR_KEY.
Replace the value of MAX_KEY_LENGTH to also include the LENGTH and NULL BYTES
of a field.

Workaround glibc bug: https://sourceware.org/bugzilla/show_bug.cgi?id=20116
by making unittest threads joinable. It makes code better anyway.

This reverts part of c5427172

with InnoDB, joins, AND/OR conditions

The inited parameter handler is not initialised when we do a quick_select after a table scan.

Forbid ALTER DATABASE under read_only.

This is a backport of a part of
commit 18455ec3
from 10.1.

Problem:

  Innodb_checksum_algorithm checks for all checksum algorithm to
validate the page checksum even though the algorithm is specified as
strict_crc32, strict_innodb, strict_none.

Fix:

   Remove the checks for all checksum algorithm to validate the page
checksum if the algo is specified as strict_* values.

Current implementation is conflicting. If UNICODE is defined, FormatMessage() will be FormatMessageW(), and variable win_errormsg with type char can not be passed to it, which should be changed to TCHAR instead. Since we don't use UNICODE here, we can use FormatMessageA() directly to avoid conversion error.
```
my_global.h(1092): error C2664: 'DWORD FormatMessageW(D
WORD,LPCVOID,DWORD,DWORD,LPWSTR,DWORD,va_list *)' : cannot convert argument 5 from 'char [2048]' to 'LPWSTR'
```

ha_innobase::prepare_inplace_alter_table(): check max column length for every
index in a table, not just added in this particular ALTER TABLE with ADD INDEX ones.

The problem here is EITS statistics does not calculate statistics for the partitions of the table.
So a temporary solution would be to not read EITS statistics for partitioned tables.

Also disabling reading of EITS for columns that participate in the partition list of a table.

create_table_def(), ha_innobase::create(): Defer fts_optimize_add_table()
until after the table has been successfully created.

merge_role_db_privileges() was remembering pointers into Dynamic_array
acl_dbs, and later was using them, while pushing more elements into the
array. But pushing can cause realloc, and it can invalidate all pointers.

Fix: remember and use indexes of elements, not pointers.

MDEV-16499 [10.1] ER_NO_SUCH_TABLE_IN_ENGINE followed by "Please drop the table and recreate" upon adding FULLTEXT key to table with virtual column

There was an incorrect check for MariaDB and InnoDB
tables fields count. Corruption was reported when there was no corruption.
Also, a warning message had incorrect field numbers for both MariaDB and InnoDB
tables.

ha_innobase::open(): fixed check and message

In this case we were trying to access memory for key_parts which we did not
assign for a fields because it did not any EITS statistics.
The check if EITS statistics for a column is avaialable or not was missing.

Closes #3

The fix for "MDEV-17698 MEMORY engine performance regression"
previously fixed this problem.

- Adding the test for MDEV-17724
- Re-recording wrong results for tests:
  * engines/iuds/r/insert_number
  * engines/iuds/r/update_delete_number
  which started to fail since MDEV-17698

Also, backporting a part of:
  MDEV-11485 Split Item_func_between::val_int() into virtual methods in Type_handler
for easier merge to 10.3.

MDEV-11167: InnoDB: Warning: using a partial-field key prefix in search, results in assertion failure or "Can't find record" error

Fix ha_rnd_init() argument (we do not doing scan but use rnd_pos)