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Monty cf50e13fbd MDEV-6080: Allowing storage engine to shortcut group by queries
This task is to allow storage engines that can execute GROUP BY or
summary queries efficiently to intercept a full query or sub query from
MariaDB and deliver the result either to the client or to a temporary
table for further processing.

- Added code in sql_select.cc to intercept GROUP BY queries.
  Creation of group_by_handler is done after all optimizations to allow
  storage engine to benefit of an optimized WHERE clause and suggested
  indexes to use.
- Added group by handler to sequence engine and a group_by test suite as
  a way to test the new interface.
- Intercept EXPLAIN with a message "Storage engine handles GROUP BY"

libmysqld/CMakeLists.txt:
  Added new group_by_handler files
sql/CMakeLists.txt:
  Added new group_by_handler files
sql/group_by_handler.cc:
  Implementation of group_by_handler functions
sql/group_by_handler.h:
  Definition of group_by_handler class
sql/handler.h:
  Added handlerton function to create a group_by_handler, if the storage
  engine can intercept the query.
sql/item_cmpfunc.cc:
  Allow one to evaluate item_equal any time.
sql/sql_select.cc:
  Added code to intercept GROUP BY queries
  - If all tables are from the same storage engine and the query is
    using sum functions, call create_group_by() to check if the storage
    engine can intercept the query.
    - If yes:
       - create a temporary table to hold a GROUP_BY row or result
       - In do_select() intercept normal query execution by instead
         calling the group_by_handler to get the result
       - Intercept EXPLAIN
sql/sql_select.h:
  Added handling of group_by_handler
  Added caching of the original join tab (needed for cleanup after
  group_by handler)
storage/sequence/mysql-test/sequence/group_by.result:
  Test group_by_handler interface
storage/sequence/mysql-test/sequence/group_by.test:
  Test group_by_handler interface
storage/sequence/sequence.cc:
  Added simple group_by_engine for handling COUNT(*) and
  SUM(primary_key).  This was done as a test of the group_by_handler
  interface
2015-10-05 17:14:14 +02:00
BUILD MDEV-6650 - LINT_INIT emits code in non-debug builds 2015-03-16 14:48:22 +04:00
client MDEV-8264 encryption for binlog 2015-09-04 10:33:55 +02:00
cmake cmake: don't repeat yourself 2015-09-04 10:32:02 +02:00
dbug MDEV-6410 Cross-compile fixes 2014-07-08 19:34:53 +02:00
debian Merge branch '10.1' into pull-request-97 2015-09-25 10:24:14 +02:00
Docs MDEV-6247: Merge 10.0-galera to 10.1. 2014-08-26 15:43:46 +03:00
extra Merge branch '10.1' into pull-request-97 2015-09-25 10:24:14 +02:00
include MDEV-8764: Wrong error when encrypted table can't be decrypted. 2015-09-14 08:27:36 +03:00
libmysql Merge tag 'mariadb-10.0.20' into 10.1 2015-06-27 20:35:26 +02:00
libmysqld MDEV-6080: Allowing storage engine to shortcut group by queries 2015-10-05 17:14:14 +02:00
libservices rename {sys_vars,sql_plugin_services}.h -> *.ic 2015-06-28 12:09:46 +02:00
man Merge 10.0.14 into 10.1 2014-10-15 12:59:13 +02:00
mysql-test Speed up some innodb tests 2015-10-05 17:14:13 +02:00
mysys MDEV-8208: Sporadic SEGFAULT on startup 2015-09-25 18:50:57 -04:00
mysys_ssl New encryption API. Piece-wise encryption. 2015-09-04 10:33:50 +02:00
pcre restore CRLF file ending in the test data 2015-09-14 12:02:20 +02:00
plugin MDEV-8673 - [PATCH] Missing Sanity Check for strndup() in MariaDB 10.0.2x 2015-09-16 17:24:34 +04:00
randgen/conf Group commit for maria engine. 2010-02-12 15:12:28 +02:00
scripts MDEV-8576: Bootstrap should ignore --enforce-storage-engine option 2015-09-16 13:14:19 +03:00
sql MDEV-6080: Allowing storage engine to shortcut group by queries 2015-10-05 17:14:14 +02:00
sql-bench Merge branch '10.0' into merge-wip 2015-01-31 21:48:47 +01:00
sql-common MDEV-6152: Remove calls to current_thd while creating Item 2015-09-01 18:42:02 +03:00
storage MDEV-6080: Allowing storage engine to shortcut group by queries 2015-10-05 17:14:14 +02:00
strings MDEV-8466 CAST works differently for DECIMAL/INT vs DOUBLE for empty strings 2015-09-17 11:05:07 +04:00
support-files Update mandatory wsrep configuration options 2015-09-19 09:08:58 -04:00
tests MDEV-6066: Merge new defaults from 5.6 and 5.7 (defaults changed, QC can be stopped with no-zero size) 2015-09-04 10:33:56 +02:00
unittest make encrypt-binlog and encrypt-tmp-files to fail if no encryption 2015-09-09 14:22:22 +02:00
vio Merge commit '96badb16afcf' into 10.0 2015-08-03 23:09:43 +03:00
win Merge branch '10.0' into 10.1 2015-09-03 12:58:41 +02:00
wsrep compiler warnings 2015-01-31 21:51:45 +01:00
zlib Backport from trunk: 2014-05-07 17:09:14 +02:00
.gitattributes .gitattributes: pcre/testdata/greppatN4 -text 2015-08-01 17:48:41 +02:00
.gitignore Merge 'https://github.com/Buggynours/MariaDB 10.0' into 10.0 2015-08-03 17:10:20 +02:00
BUILD-CMAKE various documentation updates 2012-06-18 16:57:58 -04:00
CMakeLists.txt Merge branch '10.0' into 10.1 2015-09-03 12:58:41 +02:00
config.h.cmake MDEV-6756: map a linux pid (child pid) to a connection id shown in the output of SHOW PROCESSLIST 2015-09-17 14:30:58 +02:00
configure.cmake MDEV-6756: map a linux pid (child pid) to a connection id shown in the output of SHOW PROCESSLIST 2015-09-17 14:30:58 +02:00
COPYING Use a new version of "COPYING", the GPL text. 2010-03-04 14:26:27 +01:00
COPYING.LESSER MWL#192: non-blocking client API, after-review fixes. 2012-01-06 12:43:18 +01:00
COPYING.thirdparty split README into the actual README and third-party licenses 2014-05-24 18:23:46 +02:00
CREDITS Updated sponsors and authors 2014-03-28 09:31:43 +02:00
EXCEPTIONS-CLIENT MDEV-5645 MariaDB-5.5.35 - references are made to an "EXCEPTIONS-CLIENT" file but it does not exist 2014-05-31 13:18:56 +02:00
INSTALL-SOURCE Merging the changes for Bug 16633169 - MYSQL.INFO CONTAINS OUTDATED INFORMATION. 2013-04-16 12:17:18 +02:00
INSTALL-WIN-SOURCE Merging the changes for Bug 16633169 - MYSQL.INFO CONTAINS OUTDATED INFORMATION. 2013-04-16 12:17:18 +02:00
KNOWN_BUGS.txt various documentation updates 2012-06-18 16:57:58 -04:00
README split README into the actual README and third-party licenses 2014-05-24 18:23:46 +02:00
VERSION Increase the version number 2015-09-14 03:15:04 +03:00

MariaDB is designed as a drop-in replacement of MySQL(R) with more
features, new storage engines, fewer bugs, and better performance.

MariaDB is brought to you by the MariaDB foundation.
Please read the file CREDITS for details about the MariaDB foundation,
and who is developing MariaDB.

MariaDB is developed by many of the original developers of MySQL who
now work for MariadB foundation and SkySQL Ab, and by many people in
the community.

MySQL, which is the base of MariaDB, is a product and trademark of Oracle
Corporation, Inc. For a list of developers and other contributors,
see the Credits appendix.  You can also do 'SHOW authors' to get a
list of active contributors.

A description of the MariaDB project and a manual can be found at:
http://mariadb.org/
https://mariadb.com/kb/en/
https://mariadb.com/kb/en/mariadb-vs-mysql-features/
https://mariadb.com/kb/en/mariadb-versus-mysql-features/
https://mariadb.com/kb/en/mariadb-versus-mysql-compatibility/

As MariaDB is a full replacement of MySQL, the MySQL manual at
http://dev.mysql.com/doc is generally applicable.

More help is available from the Maria Discuss mailing list
https://launchpad.net/~maria-discuss
and the #maria IRC channel on Freenode.

***************************************************************************

NOTE: 

MariaDB is specifically available only under version 2 of the GNU
General Public License (GPLv2). (I.e. Without the "any later version"
clause.) This is inherited from MySQL. Please see the README file in
the MySQL distribution for more information.

License information can be found in the COPYING, COPYING.LESSER,
and COPYING.thirdparty files.

***************************************************************************

IMPORTANT:

Bug and/or error reports regarding MariaDB should be submitted at
http://mariadb.org/jira

Bugs in the MySQL code can also be submitted at http://bugs.mysql.com

The code for MariaDB, including all revision history, can be found at:
https://github.com/MariaDB/server

***************************************************************************