sqlite file format, anyone?

[Matthew Vanecek]

On Mon, 2003-06-23 at 14:25, Derek Neighbors wrote:
> >> > > > Ok, this implies we cannot do multi-user on MySQL
> >> > >
> >> > > You can't do multi-user with MySQL because of the problems with
> >> locking, and because I'm pretty sure that 'real' multi-user
> >> installations will need the balance checkpointing which needs
> >> stored proceedures.  You can probably work around the events issue
> >> by sticking them in a table, and polling that table.
> >> >
> >> > I am still not coninvinced there is any locking problem here.  Also,
> >>
> >> Can you nest table locks in mysql?  I thought you couldn't.  Can you
> >> rollback? i.e. start to make changes and then decide to skip it?
> >
> > Yes, you can rollback.  I don't know about nested table locks offhand.
> 
> In a multi-user system why on earth would you want to lock a table, much
> less multiple tables at a time?  I would suspect that as a serious design
> flaw.
> 

You lock a table in order to perform updates on the table, in the
absence of row or page level locks.  Standard DBMS practice.  Not a
design flaw--it's a feature, to prevent corruption of data.  Lock
tables, perform updates, unlock tables.  Anyone else will get a
contention error, and either retry their transaction or do other error
handling.


-- 
Matthew Vanecek
perl -e 'print $i=pack(c5,(41*2),sqrt(7056),(unpack(c,H)-2),oct(115),10);'
********************************************************************************
For 93 million miles, there is nothing between the sun and my shadow except me.
I'm always getting in the way of something...