cloudstack-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Prasanna Santhanam <...@apache.org>
Subject questions in guest_os tables
Date Sun, 28 Oct 2012 06:01:48 GMT
I was looking at the mapping of guest_os types and found the following
three tables:

guest_os_category, guest_os, guest_os_hypervisor

a. guest_os_category - contains the different distributions
(centos,redhat, etc) as categories

b. guest_os - lists the common set of guest_os's supported across every
hypervisor. correct?

c. guest_os_hypervisor - lists (exhaustive?) all the OSs supported by
each hypervisor.

Some questons I have
1. guest_os_category has a `name` column that is always null. What is
the purpose of this column? Why is it null?

2. guest_os.name, guest_os.display_name, guest_os_hypervisor.guest_os_name - what's the difference?

For eg:
mysql> select * from guest_os_hypervisor where guest_os_name like 'CentOS 5.5%';
+-----+-----------------+---------------+-------------+
| id  | hypervisor_type | guest_os_name | guest_os_id |
+-----+-----------------+---------------+-------------+
| 193 | KVM             | CentOS 5.5    |         111 |
| 194 | KVM             | CentOS 5.5    |         112 |
+-----+-----------------+---------------+-------------+
2 rows in set (0.00 sec)

mysql> select * from guest_os where display_name like 'CentOS 5.5%';
+-----+-------------+------+--------------------------------------+---------------------+
| id  | category_id | name | uuid                                 | display_name        |
+-----+-------------+------+--------------------------------------+---------------------+
| 111 |           1 | NULL | 3ffadb73-cda1-47a0-bb7a-06dcd52fc05a | CentOS 5.5 (32-bit) |
| 112 |           1 | NULL | 3ff86514-52f7-40b8-9de6-43abf916ec16 | CentOS 5.5 (64-bit) |
+-----+-------------+------+--------------------------------------+---------------------+
2 rows in set (0.00 sec)

3. I'm unable to tell whether guest_os derives from
guest_os_hypervisor or vice-versa? From what I understood - guest_os
is a filtered list built off guest_os_hypervisor. Is this correct?

If not - guest_os_hypervisor doesn't contain any foreign keys
referring to guest_os although it uses various ostype ids from that
table. Why is that? Should a foreign key be added?

mysql> show create table guest_os_hypervisor\G
*************************** 1. row ***************************
       Table: guest_os_hypervisor
Create Table: CREATE TABLE `guest_os_hypervisor` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `hypervisor_type` varchar(32) NOT NULL,
  `guest_os_name` varchar(255) NOT NULL,
  `guest_os_id` bigint(20) unsigned NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=266 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

mysql> show create table guest_os\G
*************************** 1. row ***************************
       Table: guest_os
Create Table: CREATE TABLE `guest_os` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `category_id` bigint(20) unsigned NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  `uuid` varchar(40) DEFAULT NULL,
  `display_name` varchar(255) NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uc_guest_os__uuid` (`uuid`),
  KEY `fk_guest_os__category_id` (`category_id`),
  CONSTRAINT `fk_guest_os__category_id` FOREIGN KEY (`category_id`) REFERENCES `guest_os_category`
(`id`) ON DELETE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=204 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)


Thanks,

-- 
Prasanna.,

Mime
View raw message