[sr-dev] Fwd: version of s tables

[Jan Janak]

Forgot to include the list, sorry


---------- Forwarded message ----------
From: Jan Janak <jan at ryngle.com>
Date: Fri, Jul 3, 2009 at 12:20 PM
Subject: Re: [sr-dev] version of s tables
To: Juha Heinanen <jh at tutpro.com>


Juha,

On Thu, Jul 2, 2009 at 5:46 PM, Juha Heinanen<jh at tutpro.com> wrote:
> in scripts/mysql/my_create.sql there is no version table.  does it mean
> that s ser database tables don't have any version number?  if so, they
> have to be added in order to allow easy db table upgrade.

That is correct. In SER we ditched the version table because it is not
needed anymore. The db API of SER relies on pre-compiled statements. Such
statements are created at startup time. Before a pre-compiled statement
is created, the database layer checks whether it is compatible with the
database table on the server. These checks are much more detailed, we
verify the types of individual columns, whether we can convert them to
column types specified in SER modules, and so on.

In other words, instead of checking just the version number, we go down
to individual columns of all database queries declared by a module and
verify that they are all compatible with the schema on the database server.

For mixed setups, i.e. one where you mix ser and kamailio modules, we might
need to add the version table from kamailio, but only tables used from
kamailio modules need to be present there.

  Jan.