[Koha-devel] Serious problem

[David Cook]

A quick look through the data for one library which recently had this
problem shows that I'm wrong about the frequency of issues/reserves vs
deleted biblios actually.

Very low circulation but lots of deleted records.

David Cook
Systems Librarian
Prosentient Systems
72/330 Wattle St
Ultimo, NSW 2007
Australia

Office: 02 9212 0899
Direct: 02 8005 0595


> -----Original Message-----
> From: David Cook [mailto:dcook at prosentient.com.au]
> Sent: Tuesday, 6 September 2016 11:57 AM
> To: 'Chris Cormack' <chrisc at catalyst.net.nz>
> Cc: 'Koha-devel' <koha-devel at lists.koha-community.org>
> Subject: RE: [Koha-devel] Serious problem
> 
> Mmm, I think that I see what you're saying. In theory, for a library with
high
> circulation, you would always have a newer checkout in the issues table,
> when you're doing a check-in, so it's unlikely that your IDs in the issues
table
> would be lower than your IDs in your old_issues table.
> 
> When I referred to frequency, I meant that there is probably a higher
> frequency of checking in items or fulfilling/cancelling reserves than
deleting
> biblio records, although I suppose that's a subjective claim.  In any
case, that's
> a good point that the auto_increment is more likely to happen in a library
> with low circulation than high circulation.
> 
> I've noticed this problem for years, but previously my communications
about
> it have been ignored, so we've just mitigated it locally via scripts.
Historically,
> we thought it only happened after running OPTIMZE TABLE, but thanks to
> Mark we see that it's also after MySQL server restarts.
> 
> David Cook
> Systems Librarian
> Prosentient Systems
> 72/330 Wattle St
> Ultimo, NSW 2007
> Australia
> 
> Office: 02 9212 0899
> Direct: 02 8005 0595
> 
> 
> > -----Original Message-----
> > From: Chris Cormack [mailto:chrisc at catalyst.net.nz]
> > Sent: Tuesday, 6 September 2016 11:40 AM
> > To: David Cook <dcook at prosentient.com.au>
> > Cc: 'Koha-devel' <koha-devel at lists.koha-community.org>
> > Subject: Re: [Koha-devel] Serious problem
> >
> > * David Cook (dcook at prosentient.com.au) wrote:
> > >
> > > Chris, what about deletedbiblio and deletedbiblioitem tables? The
> > > history there might be more important, as I think we're now
> > > including those in the OAI-PMH responses? I reckon those tables
> > > would be vulnerable to this as well, although perhaps less likely
> > > due to issues and reserves being more high frequency in terms of
> inserts/deletions.
> > >
> >
> > As Katrin rightly pointed out to me, frequency is not really the issue.
> > This is only a problem when the most recently inserted item is
> > deleted/return/issued.
> > And then the server is restarted right then.
> >
> > If you delete from anywhere except the tip of the table, it doesn't
matter.
> > So if you issue and return something (before anyone else issues
> > something) and restart the server then you have the problem with issues.
> > So in fact the higher the frequency the way less likely this will be to
> happen.
> >
> > It will most likely only ever happen in a library that does almost no
> circulation.
> >
> > Chris
> >
> > --
> > Chris Cormack
> > Catalyst IT Ltd.
> > +64 4 803 2238
> > PO Box 11-053, Manners St, Wellington 6142, New Zealand