BIND 10 #963: Utility to upgrade SQLite schema

[BIND 10 Development]

#963: Utility to upgrade SQLite schema
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            Reporter:  shane         |                        Owner:
                Type:  enhancement   |                       Status:  new
            Priority:  major         |                    Milestone:  New
           Component:  data source   |  Tasks
           Sensitive:  0             |                     Keywords:
         Sub-Project:  DNS           |              Defect Severity:  N/A
Estimated Difficulty:  0             |  Feature Depending on Ticket:
         Total Hours:  0             |  sqlite schema upgrade
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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 We need a utility to upgrade the SQLite schema, so that we can change it
 if we need to.

 This work is necessary to implement the changes in the branch for ticket
 #324. That ticket has the server automatically upgrade the SQL version at
 startup. While this is nice for small databases, for large databases this
 could cause a large delay in startup, which is not good for
 administrators. A better solution is to have a utility, so administrators
 can plan the upgrade, or do it offline.

 A utility might work as follows:

   1. Use the BIND 10 installed SQLite database, unless set to a different
 one via command-line switch, or perhaps environment variable (if we do
 that already).
   1. Confirm that the system is not running (at least for now), and exit
 with an error message if it is.
   1. Prompt the administrator for confirmation before upgrading, unless a
 command-line switch is given.
   1. Backup the old SQLite database.
   1. Convert the database by altering the schema.

 Eventually it might be nice to allow administrators to revert to earlier
 versions, but for now providing the backup should be good enough.

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Ticket URL: <http://bind10.isc.org/ticket/963>
BIND 10 Development <http://bind10.isc.org>
BIND 10 Development