Please review this.

Great work! I think at a later date we should maybe look at breaking out the larger code segments from places like ha_calpont_execplan.cpp into separate files. But that is more of a cleanup task. Very happy to see this!

For QA: This basically pushes down GROUP BY queries into ColumnStore when vtable mode is disabled. Whilst this is only slightly useful now (much better performance when vtable is off) it will be very useful when we get to a point where we can get rid of vtable. There is a new set of regression tests called "test022" which covers this.

/root/columnstore/mariadb-columnstore-server
commit 4334641df0df040e0f53332c11dc8e29dc34b8b7
Merge: 960853c cd5e845
Author: David.Hall <david.hall@mariadb.com>
Date: Mon Apr 9 13:23:44 2018 -0500

Merge pull request #107 from mariadb-corporation/dev-merge-up-20180409

Dev merge up 20180409

/root/columnstore/mariadb-columnstore-server/mariadb-columnstore-engine
commit e79daac8a9b1c8047aeabc3d73ae137cc151f84e
Merge: 8790177 8a3c5e0
Author: Andrew Hutchings <andrew@linuxjedi.co.uk>
Date: Tue May 15 15:34:19 2018 +0100

Merge pull request #472 from drrtuy/MCOL-1073

MCOL-1073 Removed DecomSrv

ssd=31.250
hdd=88.530
usb=193.684

1.1.3-1 10g dbt3

select l_shipmode from lineitem where l_shipmode='AIR' group by l_shipmode,l_receiptdate;
vtablemode=1
disk run: 2.32 sec
cache run: 1.43 sec
vtablemode=0
disk run: 7.17 sec
cache run: 6.85 sec

1.2.0-1 10g dbt3

select l_shipmode from lineitem where l_shipmode='AIR' group by l_shipmode,l_receiptdate;
vtablemode=1
disk run: 2.10 sec
cache run: 1.48 sec
vtablemode=0
disk run: 2.23 sec
cache run: 1.18 sec

Attempted running regression test022 and it is not yet working. Possibly code is not yet merged. Will try regression test later.

Build verified: 1.2.0-1 source

/root/columnstore/mariadb-columnstore-server
commit 3bfc3ad5f1e91e6f325b89fefaf62a6b38ca889a
Merge: 4334641 742af4d
Author: David.Hall <david.hall@mariadb.com>
Date: Thu May 31 09:40:12 2018 -0500

Merge pull request #119 from mariadb-corporation/1.1-merge-up-20180531

Merge develop-1.1 into develop

/root/columnstore/mariadb-columnstore-server/mariadb-columnstore-engine
commit 29346339adf385d21cb5f9b1cae4c830f8cddb12
Merge: e79daac 1a1f3ea
Author: Andrew Hutchings <andrew@linuxjedi.co.uk>
Date: Thu May 31 13:33:49 2018 +0100

Merge pull request #486 from drrtuy/MCOL-1449

MCOL 1449 Fix the regression in sorting orientation.

There is an issue with regression test022 due to unrelated issue. Close this ticket since the fix is working. Will check for regression in future builds.