[mythtv-users] Slow MySQL query after delete

[David Rees]

On 9/5/07, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> On 09/05/2007 04:27 PM, David Rees wrote:
> > 4.0 is "Actively" supported until the end of this month. Are there
> > really any significant number of users using anything older than 4.1?
>
> That I can't tell you.  I'm definitely not "in the know" about distros.

If maintaining backwards compatibility is as big an issue as you say,
I'd seriously consider dropping support for anything old. People still
running those old versions will either upgrade MySQL or stick with the
MythTV they've got. That's the risk they take with running such old,
barely maintained (if at all) software!

> And each developer should have MySQL (various versions), PostgreSQL, ...
> installed on their networks (complete with a means of copying valid
> (and/or invalid :) data across to each) to be able to test any DB-access
> code changes?

No, not necessarily. Many projects support multiple DBs, though the
best supported DB is the one one that most of the devs run.

> Assuming you've covered all the SQL differences.  Any time you're
> talking about a call-level language, the interpreter/compiler of the
> commands becomes relevant.  Sure, maybe you're not using Native SQL
> (i.e. which is useful, "if you want to utilize database specific
> features"), but I'd love to see the BUSQ (Big, Ugly Scheduler Query)
> done without native SQL.  (Sure, it could be done, but would probably
> require a /significant/ amount of supporting code that moves finding
> positives for scheduling from the DB to the Myth code.)

I haven't actually looked at the queries, but the Hibernate query
language is very flexible. I haven't seen many queries that couldn't
be ported to Hibernate. The biggest issue when moving to Hibernate is
if you use stored procedures, but since MythTV still supports versions
of MySQL which don't have SP support... ;-)

Most of this discussion is moot without having a suitable DB
abstraction library for C++, though, and I haven't even begun to see
if there is anything that might be suitable.

-Dave