[mythtv-users] Slow MySQL query after delete

[David Rees]

On 9/4/07, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> Basically, one of the biggest benefits is that we could move all efforts
> to supporting embedded MySQL 5.5 or whatever and could drop support for
> MySQL 3.23, MySQL 4.0, MySQL 4.1, MySQL 5.0, ...  There's a /lot/ of
> performance-draining "backwards compatibility" in the code we have now.
> If all users had the same DB engine, things would be a /lot/ easier.

You really should think about dropping support for anything older than
4.1. What's the point in maintaining anything that the upstream vendor
doesn't support themselves?

> Maintaining support for all the "shipping in standard distributions"
> versions of MySQL is hard enough.  Add in totally different DB engines
> and things get exponentially worse.  Does the company you work for spend
> the money to make truly DBMS-independent applications?  So, why should
> Myth do so?  (If the answer to the first question was, "Yes," then
> nevermind--I won't be able to catch you up. :)

My day job involves writing backend code for high performance
websites. While I don't need to write database independant code, I use
tools (Java and Hibernate) that allow me to swap backends with a
minimal amount of fuss. With Hibernate, all I have to do is swap out a
couple configuration lines and the migration is complete, no code
change required. As a bonus, it also forces me to abstract away 99% of
SQL code so it's trivial to write a backend process that handles all
the SQL and implements client interfaces of your choice. And the
amount of work that goes into maintaining that abstraction layer is no
more than maintaining a the interface to a single database.

Using Hibernate, I've personally swapped backends between MySQL,
Sybase and Postgres without changing a line of code.

Certainly something similar exists for C++? I'm not much of a C/C++
programmer so I've never looked, but I have used perl DBI libraries
for similar jobs (though none very big).

-Dave