Derived table creation code would call Field::make_new_field() which would
memcpy the Field object from the source table, including Field::read_stats.

But the temp. table as a whole had table->stats_is_read=false. Which was
correct but not consistent with Field::read_stats and caused an assertion.

Fixed by making sure that Field::read_stats=NULL for fields in the new
temporary (i.e. work) tables.

The problem, introduced in patch for MDEV-26301:

When check_join_cache_usage() decides not to use join buffer, it must
adjust the access method accordingly. For BNL-H joins this means switching
from pseudo-"ref access"(with index=MAX_KEY) to some other access method.

Failing to do this will cause assertions down the line when code that is
not aware of BNL-H will try to initialize index use for ref access with
index=MAX_KEY.

The fix is to follow the regular code path to disable the join buffer for
the join_tab ("goto no_join_cache") instead of just returning from
check_join_cache_usage().

Do not try to decide merge/materialize for derived if it was already decided
(even if it is a view).

RocksDB (in a submodule) has to include <cstdint> to use uint64_t
but it doesn't. Until the submodule is upgraded, let's replace
problematic types with something that's available

select_insert::store_values() must reset
has_value_set bitmap before every row, just like mysql_insert() does.
because ON DUPLICATE KEY UPDATE and triggers modify it

Temporary fix to avoid the server crash.

Add Optimizer Trace printouts.

This patch optimizes the number of refills for the lateral derived table
to which a materialized derived table subject to split optimization is
is converted. This optimized number of refills is now considered as the
expected number of refills of the materialized derived table when searching
for the best possible splitting of the table.

(part 1 is in the previous commit)
to [ pass ] galera.MDEV-18832, galera.MDEV-27862

1. log_event.cc stuff should go into log_event_server.cc
2. the test's wait condition is textually different in 10.5, fixed.
3. pre-exec 'optimistic' global var value is correct for 10.5 indeed.

This bug could cause a crash of the server when processing a query with
ROWNUM() if it used in its FROM list a reference to a mergeable view
defined as SELECT over more than one table that contained ORDER BY clause.
When a mergeable view with ORDER BY clause and without LIMIT clause is used
in the FROM list of a query that does not have ORDER BY clause the ORDER BY
clause of the view is moved to the query. The code that performed this
transformation forgot to delete the moved ORDER BY list from the view.
If a query contains ROWNUM() and uses a mergeable multi-table view with
ORDER BY then according to the current code of TABLE_LIST::init_derived()
the view has to be forcibly materialized. As the query and the view shared
the same items in its ORDER BY lists they could not be properly resolved
either in the query or in the view. This led to a crash of the server.

This patch has returned back the original signature of LEX::can_not_use_merged()
to comply with 10.4 code of the condition that checks whether a megeable
view has to be forcibly materialized.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

To make sure that PMEM problem does not happen again sync
10.9 and up debian/rules to make sure that they are not making
anymore problems with autobake-debs.sh

- Update wsrep-lib which contains fix for the assertion
- Fix error handling for appending fragment to streaming log,
  make sure tables are closed after rollback.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

changed tast case 2 to be deterministic
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

When processing a query over a mergeable view at some conditions checked
at prepare stage it may be decided to materialize the view rather than
to merge it. Before this patch in such case the field 'derived' of the
TABLE_LIST structure created for the view remained set to 0. As a result
the guard condition preventing range analysis for materialized views did
not work properly. This led to a call of some handler method for the
temporary table created to contain the view's records that was supposed
to be used only for opened tables. However temporary tables created for
materialization of derived tables or views are not opened yet when range
analysis is performed.

Approved by Oleksandr Byelkin <sanja@mariadb.com>

Adding virtual methods to class Schema:

  make_item_func_replace()
  make_item_func_substr()
  make_item_func_trim()

This is a non-functional preparatory change for MDEV-27744.

The fix was introduced, along with re-ordering to do other macros that check test environment capabilities before master/slave is set up.

Variant #2.

When Histogram::point_selectivity() sees that the point value of interest
falls into one bucket, it tries to guess whether the bucket has many
different (unpopular) values or a few popular values. (The number of
rows is fixed, as it's a Height-balanced histogram).
The basis for this guess is the "width" of the value range the bucket
covers. Buckets covering wider value ranges are assumed to contain
values with proportionally lower frequencies.

This is just a [brave] guesswork. For a very narrow bucket, it may
produce an estimate that's larger than total #rows in the bucket
or even in the whole table.

Remove the guesswork and replace it with basic logic: return
either the per-table average selectivity of col=const, or selectivity
of one bucket, whichever is lower.