on UPDATE and INSERT if the table had special columns.
modified:
  storage/connect/tabfmt.cpp

modified:
  storage/connect/colblk.h
  storage/connect/reldef.h
  storage/connect/tabfmt.cpp

- Fix length specification and writing (when using FIELD_FORMAT) of DECIMAL columns
modified:
  storage/connect/ha_connect.cc
  storage/connect/tabdos.cpp

- Add the D field_format option (specifying the decimal separator character)
modified:
  storage/connect/tabdos.cpp
  storage/connect/tabdos.h
  storage/connect/tabfmt.cpp

  string was not an URL but a server name. Also make the dbname option
  to be recignized in create (was only seached in option_list)
modified:
  storage/connect/ha_connect.cc
  storage/connect/tabmysql.cpp

  occured when the table definition had a special column that was not skipped
  from the header.
modified:
  storage/connect/filamdbf.cpp

- Update some test cases to reflect a change of error message generated when
  trying to update or delete a read only table.
modified:
  storage/connect/mysql-test/connect/r/csv.result
  storage/connect/mysql-test/connect/r/dbf.result
  storage/connect/mysql-test/connect/r/fix.result
  storage/connect/mysql-test/connect/r/ini.result
  storage/connect/mysql-test/connect/r/vec.result
  storage/connect/mysql-test/connect/t/csv.test
  storage/connect/mysql-test/connect/t/dbf.test
  storage/connect/mysql-test/connect/t/fix.test
  storage/connect/mysql-test/connect/t/ini.test
  storage/connect/mysql-test/connect/t/vec.test

  column is defined in a CSV table (MDEV-6187)
modified:
  storage/connect/ha_connect.cc
  storage/connect/reldef.h
  storage/connect/tabfmt.cpp

modified:
  storage/connect/odbconn.cpp
  storage/connect/xindex.cpp

  not to be unmapped. This caused a crash instead of reporting an
  error. This was also fixed.
modified:
  storage/connect/connect.cc
  storage/connect/ha_connect.cc
  storage/connect/maputil.cpp
  storage/connect/table.cpp
  storage/connect/xindex.cpp
  storage/connect/xindex.h
  storage/connect/xtable.h

  See the issue reported in MDEV-6142.
modified:
  storage/connect/myconn.cpp
  storage/connect/myconn.h
  storage/connect/tabmysql.cpp
  storage/connect/tabmysql.h

  tables when they are Multiple or Compressed.
modified:
  storage/connect/ha_connect.cc
  storage/connect/tabdos.h

modified:
  storage/connect/ha_connect.cc
  storage/connect/odbconn.cpp

  This was working but the cause probably comes from freeing Xop object to
  handle memory leaks reported by Valgrind.
  Also add a test case on XML multiple tables.
added:
  storage/connect/mysql-test/connect/r/xml_mult.result
  storage/connect/mysql-test/connect/std_data/bookstore.xml
  storage/connect/mysql-test/connect/t/xml_mult.test
modified:
  storage/connect/domdoc.cpp
  storage/connect/tabxml.cpp
  storage/connect/tabxml.h

- Enhance the index types and flages returning functions.
modified:
  storage/connect/ha_connect.cc
  storage/connect/ha_connect.h

- Suppress irrelevant warning message (MDEV-6117)
modified:
  storage/connect/ha_connect.cc

  Not yet done for ODBC tables.
modified:
  storage/connect/connect.cc
  storage/connect/ha_connect.cc
  storage/connect/ha_connect.h
  storage/connect/mycat.cc
  storage/connect/plgdbsem.h
  storage/connect/reldef.h
  storage/connect/tabdos.h
  storage/connect/tabmysql.cpp
  storage/connect/tabmysql.h
  storage/connect/tabodbc.cpp
  storage/connect/tabodbc.h
  storage/connect/xindex.cpp
  storage/connect/xtable.h

- Return error in "info" on Cardinality error.
modified:
  storage/connect/ha_connect.cc

- Backport the fix for MySQL Bug#13947868
- Add our testcase (they don't publish theirs)

back-ported the patch for bug #13256831 from mysql-5.6 code line.

  Here's the comment this patch was provided with:

  Fixed bug#13256831 - ERROR 1032 (HY000): CAN'T FIND RECORD.

  This bug only occurs if a user tries to update a base table using
  an updatable view and this view was created as a join for which
  the clause 'WITH CHECK OPTION' was specified.

  The reason for the bug was that when such an update was
  executed, row positions were not properly handled for tables
  that were not updated but had constraints that had to be
  checked due to the 'WITH CHECK OPTION' clause.

  The reason for the bug was that when such update is executed
  then for tables specified in the view definition and
  also listed in the 'WITH CHECK OPTION' clause the positioning to
  row being updated is not performed.

Removed unused result files.

  catalog data path had not been set. This was added into ha_connect::info.
modified:
  storage/connect/ha_connect.cc

- All the functions querying table options could return information from the wrong
  table when several CONNECT tables were used in the same query (for instance joined
  together) This was because they belonged to the catalog class that is shared between
  all tables in the same query. They have been moved from the catalog class to the
  TABDEF/RELDEF class that is attached to each table. This was a major potential bug.
modified:
  storage/connect/catalog.h
  storage/connect/filamvct.cpp
  storage/connect/filamzip.cpp
  storage/connect/mycat.cc
  storage/connect/mycat.h
  storage/connect/reldef.cpp
  storage/connect/reldef.h
  storage/connect/tabdos.cpp
  storage/connect/tabfmt.cpp
  storage/connect/tabmul.cpp
  storage/connect/tabmysql.cpp
  storage/connect/taboccur.cpp
  storage/connect/tabodbc.cpp
  storage/connect/tabpivot.cpp
  storage/connect/tabsys.cpp
  storage/connect/tabtbl.cpp
  storage/connect/tabutil.cpp
  storage/connect/tabvct.cpp
  storage/connect/tabwmi.cpp
  storage/connect/tabxcl.cpp
  storage/connect/tabxml.cpp
  storage/connect/xindex.cpp

- Prepare indexing of MYSQL/ODBC tables (as does FEDERATED) (Not implemented yet)
modified:
  storage/connect/ha_connect.cc
  storage/connect/ha_connect.h
  storage/connect/mycat.cc
  storage/connect/mycat.h

- Typo
modified:
  storage/connect/plgdbutl.cpp

Add a testcase and backport this fix:

Bug#14338686: MYSQL IS GENERATING DIFFERENT AND SLOWER
              (IN NEWER VERSIONS) EXECUTION PLAN
PROBLEM:
While checking for an index to sort for the order by clause
in this query
"SELECT datestamp FROM contractStatusHistory WHERE
contract_id = contracts.id ORDER BY datestamp asc limit 1;"

we do not calculate the number of rows to be examined correctly.
As a result we choose index 'idx_contractStatusHistory_datestamp'
defined on the 'datestamp' field, rather than choosing index
'contract_id'. And hence the lower performance.

ANALYSIS:
While checking if an index is present to give the records in
sorted order(datestamp), we consider the selectivity of the
'ref_key'(contract_id here) using 'table->quick_condition_rows'.
'ref_key' here can be an index from 'REF_ACCESS' or from 'RANGE'.

As this is a 'REF_ACCESS', 'table->quick_condition_rows' is not
set to the actual value which is 2. Instead is set to the number
of tuples present in the table indicating that every row that
is selected would be satisfying the condition present in the query.

Hence, the selectivity becomes 1 even when we choose the index
on the order by column instead of the join_condition.

But, in reality as only 2 rows satisy the condition, we need to
examine half of the entire data set to get one tuple when we
choose index on the order by column.
Had we chosen the 'REF_ACCESS' we would have examined only 2 tuples.
Hence the delay in executing the query specified.
  
FIX:
While calculating the selectivity of the ref_key:
For REF_ACCESS consider quick_rows[ref_key] if range 
optimizer has an estimate for this key. Else consider 
'rec_per_key' statistic.
For RANGE ACCESS consider 'table->quick_condition_rows'.

modified:
  storage/connect/ha_connect.cc
  storage/connect/tabpivot.cpp
  storage/connect/tabpivot.h

modified:
  storage/connect/ha_connect.cc
  storage/connect/ha_connect.h
  storage/connect/xindex.cpp

- Optimize retrieving numeric values in scan_record. Was previously
  translating numeric values to character representation back and forth.
modified:
  storage/connect/ha_connect.cc
  storage/connect/mysql-test/connect/r/xml.result

- Modify Pivot table creation to avoid reading the entire source table
  when making columns from Discovery. MDEV-6024
modified:
  storage/connect/tabpivot.cpp

- Make JOIN::const_key_parts include keyparts for which 
  the WHERE clause has an equality in form 
  "t.key_part=reference_outside_this_select"
- This allows to avoid filesort'ing in some cases (and also 
  avoid a difficult choice between using filesort or using an index)

10.0 variation of the problem was that system tables were altered
during mysql_upgrade process using old (smaller) column lengths. 
At the end the tables were altered again, so the structure was restored,
but if there were long values before the upgrade, they were truncated.
Fixed by using correct column length in alter statements.

MDEV-5401: Wrong result (missing row) on a 2nd execution of PS with exists_to_in=on, MERGE view or a SELECT SQ

The problem was that the view substitute its fields (on prepare) with reverting the change after execution. After prepare on optimization exists2in convertion substituted arguments of '=' with constsnt '1', but then one of the arguments of '=' was reverted to the view field reference.This lead to incorrect WHERE condition on the second execution.

To fix the problem we replace whole '=' with '1' permannently.

We need to use mysql_cond_broadcast() rather than _signal for
COND_thread_count, as there can be multiple waiters.

Thanks to Pavel Ivanov for reporting both the problem and the
solution.

The code did not correctly handle the update of position for Rotate events in the
binlog/relaylog when using parallel replication.

  normally when too big to be suballocated) to handle big results.
modified:
  storage/connect/valblk.cpp
  storage/connect/valblk.h

- Add system variable connect_work_size giving the size of the CONNECT
  work area used for memory allocation.
modified:
  storage/connect/ha_connect.cc
  storage/connect/plugutil.c
  storage/connect/user_connect.cc

  Exhausted memory cause un-prepared long jump
  Issue proper message when PIVOT column is nullable
modified:
  storage/connect/mysql-test/connect/r/pivot.result
  storage/connect/mysql-test/connect/t/pivot.test
  storage/connect/plgdbsem.h
  storage/connect/tabpivot.cpp

- Prepare adding index_prev (not used yet)
modified:
  storage/connect/plgdbsem.h
  storage/connect/xindex.cpp
  storage/connect/xindex.h

MDEV-5984: EITS: Incorrect filtered% value for single-table select with range access
- Fix calculate_cond_selectivity_for_table() to work correctly with range accesses 
  over multi-component keys:
  = First, take selectivity of all possible range scans into account. Remember which 
    fields were used bt the range scans.
  = Then, calculate selectivity produced by sargable predicates on fields. If a 
    field was used in a possible range access, assume its selectivity is already
    taken into account.
- Fix table_cond_selectivity(): when quick select is used, selectivity of
  COND(table) is taken into account in matching_candidates_in_table(). In
  table_cond_selectivity() we should not apply it for the second time.

  By implementing index_last
modified:
  storage/connect/ha_connect.cc
  storage/connect/ha_connect.h
  storage/connect/xindex.cpp

- Adding the TYPE_BIN Connect internal type
  (not tested and not used yet)
modified:
  storage/connect/global.h
  storage/connect/value.cpp
  storage/connect/value.h

modified:
  storage/connect/osutil.c
  storage/connect/plugutil.c
  
- Fix using fmt uninitialized in Tabcolumns
modified:
  storage/connect/tabutil.cpp

- Suppress gcc warning
modified:
  storage/connect/ha_connect.cc

  conversion from TEXT to VARCHAR  in PROXY and MYSQL tables.
modified:
  storage/connect/ha_connect.cc
  storage/connect/myconn.cpp
  storage/connect/myconn.h
  storage/connect/myutil.cpp
  storage/connect/tabmysql.cpp
  storage/connect/tabutil.cpp

- Add the xmap system variable addressing whether file mapping should be used
  to handle indexing.
modified:
  storage/connect/CMakeLists.txt
  storage/connect/ha_connect.cc
  storage/connect/xindex.cpp
  storage/connect/xindex.h

- Do take care of ~ in Linux version of _fullpath (not tested yet)
modified:
  storage/connect/osutil.c

asserts can be conditionally compiled out.

see MDEV-5981