[vox-tech] Need your help in recovering database.

[Tim Riley]

Jeff Newmiller wrote:

> On Wed, 23 Apr 2003, Tim Riley wrote:
>
> > Soumyadeep nandi wrote:
> >
> > > Hi All,
> > >
> > > As a naive to this field, I want to get rid of a
> > > problem, for that, I am keen, awaiting your
> > > suggestions. I doubt, I could not present my case in
> > > front of you properly. Anyway, my problem spins around
> > > the following.
>
> [...]
>
> > > Then after enquirying for the problem in the datafile
> > > (i.e. in my system /var/lib/mysql) I found
> > > 'ibdata1' file is of '2350907392' size. What I guess,
> > > this might be giving me the error.
>
> The fact that this exceeds 2GB is certainly suspicious.  There is a
> warning in the InnoDB documentation [1] to beware of OS filesize
> limitations. They don't seem to be specific about the consequences, but I
> would not be surprised if the file was corrupt by now.  I suspect that
> using multiple data files rather than the autoextend option will be
> necessary if you are dealing with large databases.  There are kernel
> patches (options by now?) that support large file sizes, but they require
> some cooperation on the part of the application (mysql compile options)
> before they will take effect. (In the long run, switching to a 64-bit
> OS is the most effective way to address this problem.)
>
> > Do you mean the filename
> > 'ibdata1.whatever_the_extension_for_database_or_index_files_for_your_mysql_version_it'?
> >
> > You left off an extension; Mysql datafiles all have extensions.
> > Is ibdata1 one of your four table names?
>
> You don't seem to be familiar with InnoDB tables, Tim... they offer some
> useful features, but they aren't structured like normal MySQL files on
> disk. OTOH, my only experience with them has been setting them up a couple
> of times... I haven't used them for large databases, and am just barely
> aware of their configuration options.

You're right--I dunno about InnoDB. I hope Mysql doesn't fall into the feature
trap. The robustness and speed of version 3.22 is due to it's simplicity. (I have
a client running a database with over 50 tables. The largest table has over 40
million records, and its datafile size is over 4G, and the index file is over 2G.)
Mysql's simplicity is due to having 3 files per table--definition, data, and index--
and letting the operating system do the operating system stuff.

On the other hand, Oracle was written when operating system resources were
limited, and therefore Oracle does a lot of operating system stuff. Oracle can be very
stable if its memory and disk resources are monitored
and extended as needed. However, this feature-rich database engine is bloated,
slower, and accident prone.

(Just food for thought.)

>
>
> [...]
>
> > > Please advice me what should I do now to retrieve the
> > > database.
> > > Have I lost the database?
>
> I suspect so.
>
> Your questions would probably be most appropriately addressed to a mailing
> list dedicated to InnoDB or MySQL.
>
> [1] http://www.mysql.com/doc/en/InnoDB_start.html
>
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