Re: Big XML files... (was Re: [Pan-users] Re: Better processing of very large groups?)

[Ron Johnson]

On 2009-07-03 22:15, Steven D'Aprano wrote:
> On Sat, 4 Jul 2009 12:56:36 pm Ron Johnson wrote:
>
> > Also (and maybe because I'm a DBA), this problem just *screams* for
> > SQLite and a database in the "First Normal Form".
>
> Please no. SQLite has problems with NFS. It's not so much that SQLite 
> won't work on NFS as that when (not if) something breaks, it's 
> difficult to unbreak it.

Honestly, how many people who use Pan also mount $HOME over NFS?

Obviously (as in your use-case below), some people do.  But they are 
mostly in "institutional" settings, where Pan probably wouldn't be 
approved anyway.

> My employer supplies Linux desktops to prisons. We have to support a 
> browser, and the system uses NFS. After an unexpected desktop shutdown, 
> to recover Firefox 2 you just need to remove a couple of lock files. 
> For Firefox 3, we needed to open the database (read-only) with the 
> sqlite3 command-line tool, dump the data into a new sqlite database, 
> quit, replace the "locked" file with the new "unlocked" file.

That's poor transaction handling on the part of Mozilla, unless 
SQLite is *sooooo* broken that it corrupts it's data file even when 
no transactions are active.

Did you all contact Mozilla developers, or file a bug?  If they 
dismissive or not responsive, some bad publicity might get them off 
the stick...

> Needless to say, this was a major factor in use deciding not to support 
> Firefox 3 as the browser on the desktop.

I'm sure that there's some work-around hack involving mounting that 
directory in tmpfs, and then having a cron job run from the NFS 
server sweep thru all the clients, copying that .db file back to the 
main $HOME location.

But obviously that's a major hack.

--
Scooty Puff, Sr
The Doom-Bringer