Also:

• compression ratio calculation is very wrong (stupid mistake)
• there appears to be a memory leak

All the issues were down to FD and RAM leaks when using I_S.COLUMNSTORE_FILES which the pull request fixes.

Also fixed my stupid mistake in calculating compression ratios.

This bug only affects develop, no released versions.

Build tested: Source from Github

[root@localhost columnstore]# cd mariadb-columnstore-server/
[root@localhost mariadb-columnstore-server]# git show
commit 8592d353c5477940f9600566639302de9fa994c7
Merge: 3795bd4 7af4e57
Author: dhall-InfiniDB <david.hall@mariadb.com>
Date: Tue Dec 6 09:49:03 2016 -0600

Merge pull request #20 from mariadb-corporation/MCOL-441

MCOL-441 Fix segfault on SP error

[root@localhost mariadb-columnstore-server]# cd mariadb-columnstore-engine/
[root@localhost mariadb-columnstore-engine]# git show
commit d4a601b4fbc81a5929ed5b36890e70514b96803a
Merge: cb8ffed fe381ab
Author: dhall-InfiniDB <david.hall@mariadb.com>
Date: Tue Dec 6 12:26:09 2016 -0600

Merge pull request #68 from mariadb-corporation/MCOL-442

MCOL-442 Allow default zero date/datetime

Repeatedly queried from the columnstore_info schema and did not notice memory utilization keep going up.

Also test compression radio using compressed and non-compressed tables, as well as a mix of the two.

I did notice on issue with total_usage() and here is how I reproduced it.

Environment used: 1 vm with 4gb memory and 1 cpu core (Not sure if this makes a difference)

I started having a 1gt tpch1c database and another database with just the 1gb orders table. I dropped both databases and called total_usage(). The called did not return and mysqld was cranking at 99% cpu.
MariaDB [columnstore_info]> call total_usage();
---------------------------------+

---------------------------------+

---------------------------------+
1 row in set (0.09 sec)

Query OK, 0 rows affected (0.09 sec)

MariaDB [columnstore_info]> call table_usage(NULL);
-----------------------------------------------------------------

-----------------------------------------------------------------

-----------------------------------------------------------------
9 rows in set (0.18 sec)

Query OK, 0 rows affected (0.18 sec)

MariaDB [columnstore_info]> drop database tpch1c;
Query OK, 8 rows affected (0.78 sec)

MariaDB [columnstore_info]> drop database mytest;
Query OK, 1 row affected (0.15 sec)

MariaDB [columnstore_info]> call total_usage();

The last call did not return.

From another terminal:

top - 20:51:14 up 2:30, 2 users, load average: 1.37, 1.06, 0.55
Tasks: 106 total, 2 running, 104 sleeping, 0 stopped, 0 zombie
%Cpu(s): 96.9 us, 3.1 sy, 0.0 ni, 0.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 3882496 total, 1924016 free, 395912 used, 1562568 buff/cache
KiB Swap: 1572860 total, 1572088 free, 772 used. 3206396 avail Mem

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
8860 mysql 20 0 1903084 186408 21000 S 99.0 4.8 7:34.09 mysqld
21768 root 20 0 0 0 0 S 0.3 0.0 0:02.08 kworker/0:1
1 root 20 0 44512 6876 2256 S 0.0 0.2 0:00.92 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.04 kthreadd

Build verified: Github source
[root@localhost mariadb-columnstore-server]# git show
commit 8592d353c5477940f9600566639302de9fa994c7
Merge: 3795bd4 7af4e57
Author: dhall-InfiniDB <david.hall@mariadb.com>
Date: Tue Dec 6 09:49:03 2016 -0600
Merge pull request #20 from mariadb-corporation/MCOL-441
MCOL-441 Fix segfault on SP error
[root@localhost mariadb-columnstore-server]# cd mariadb-columnstore-engine/
[root@localhost mariadb-columnstore-engine]# git show
commit 7a8322dc28471b830aca243698cd7fce5bc4401c
Merge: 5c0ced8 9b6beb4
Author: dhall-InfiniDB <david.hall@mariadb.com>
Date: Wed Dec 7 10:10:22 2016 -0600
Merge pull request #73 from mariadb-corporation/MCOL-435
Mcol 435

Per MCOL-406, there is a design change for table_usage(), which takes two parameters instead of one. Verified along with MCOL-406.