This patch allows up to 64K pages for tables with DYNAMIC, COMPACT 
and REDUNDANT row types. Tables with COMPRESSED row type allows 
still only <= 16K page size. Note that single row size must be
still <= 16K and max key length is not affected.

XtraDB 5.6.16-64.2

InnoDB 5.6.16

revno: 5716
committer: Praveenkumar Hulakund <praveenkumar.hulakund@oracle.com>
branch nick: mysql_5_6
timestamp: Sat 2013-12-28 22:08:40 +0530
message:
  Bug#17862905: MYSQLDUMP CREATES USELESS METADATA LOCKS

MDEV-6095 replicate- filters for slaves with a connection name that contain an underscore are ignored

Revert revision-id: guilhem@mysql.com-20091118203617-3jfudef971r7bf2y
Implement a non-destructive fix instead.

various places in the code.

the linker script.

correct the length encoding for the extra2 frm segment. add the comment.

Fixed bug on function call when InnoDB plugin is used.

Replication caches the character sets used in a query, to be able to quickly
reuse them for the next query in the common case of them not having changed.

In parallel replication, this caching needs to be per-worker-thread. The
code was not modified to handle this correctly, so the caching in one worker
could cause another worker to run a query using the wrong character set,
causing replication corruption.

            I_S table

mdl_iterate() helper function (which is used by the plugin to iterate mdl
locks) acquired mutexes in reverse order.

Fixed by iterating MDL locks in two stages:
1. Iterate locks hash under the protection of hash mutex, store all
   lock pointers in a thread local array and increment reference counter
   for the lock.
2. Iterate local array without protection of hash mutex, handle destroyed
   locks.

It somewhat echoes hack in MDL_map_partition::move_from_hash_to_lock_mutex.

- Use floating-point division in selectivity calculations.

The problem appeared when a loose scan used a key prefix whose
last component called uint3korr in the implementation of the key_cmp
virtual function.

- Testcase. The bug is fixed by commit for MDEV-6003

- Fix table_cond_selectivity() to work correctly for ref access 
  and "keypart2=const" case.

MDEV-5980: EITS: if condition is used for REF access, its selectivity is still in filtered%
MDEV-5985: EITS: selectivity estimates look illogical for join and non-key equalities
MDEV-6003: EITS: ref access, keypart2=const vs keypart2=expr - inconsistent filtered% value
- Made a number of fixes in table_cond_selectivity() so that it returns
  correct selectivity estimates.
- Added comments in related code.
Better comments

Added a new system variable:
default_regex_flags='DOTALL,DUPNAMES,EXTENDED,EXTRA,MULTILINE,UNGREEDY'

Back-ported from the mysql 5.6 code line the patch with
the following comment:

  Fix for Bug#11757108 CHANGE IN EXECUTION PLAN FOR COUNT_DISTINCT_GROUP_ON_KEY
                       CAUSES PEFORMANCE REGRESSION

  The cause for the performance regression is that the access strategy for the
  GROUP BY query is changed form using "index scan" in mysql-5.1 to use "loose
  index scan" in mysql-5.5. The index used for group by is unique and thus each
  "loose scan" group will only contain one record. Since loose scan needs to
  re-position on each "loose scan" group this query will do a re-position for
  each index entry. Compared to just reading the next index entry as a normal
  index scan does, the use of loose scan for this query becomes more expensive.

  The cause for selecting to use loose scan for this query is that in the current
  code when the size of the "loose scan" group is one, the formula for
  calculating the cost estimates becomes almost identical to the cost of using
  normal index scan. Differences in use of integer versus floating point arithmetic
  can cause one or the other access strategy to be selected.

  The main issue with the formula for estimating the cost of using loose scan is
  that it does not take into account that it is more costly to do a re-position
  for each "loose scan" group compared to just reading the next index entry.
  Both index scan and loose scan estimates the cpu cost as:

    "number of entries needed too read/scan" * ROW_EVALUATE_COST

  The results from testing with the query in this bug indicates that the real
  cost for doing re-position four to eight times higher than just reading the
  next index entry. Thus, the cpu cost estimate for loose scan should be increased.
  To account for the extra work to re-position in the index we increase the
  cost for loose index scan to include the cost of navigating the index.
  This is modelled as a function of the height of the b-tree:

    navigation cost= ceil(log(records in table)/log(indexes per block))
                   * ROWID_COMPARE_COST;

  This will avoid loose index scan being used for indexes where the "loose scan"
  group contains very few index entries.