Re: unorthodox use of PG for a customer

Em 24/08/2018 16:07, David Gauthier escreveu:
> I tried to convince him of the wisdom of one central DB.  I'll try again.
>
> >>So are the 58 database(stores) on the workstation going to be working
> with data independent to each or is the data shared/synced between
> instances?
>
> No, 58 workstations, each with its own DB.  There's a concept of a
> "workarea" (really a dir with a lot of stuff in it) where the script
> runs.  He wants to tie all the runs for any one workarea together and
> is stuck on the idea that there should be a separate DB per workarea. 
> I told him you could just stick all the data in the same table just
> with a "workarea" column to distinguish between the workareas.  He
> likes the idea of a separate DB per workarea.  He just doesn't gt it.
>
> >>I'm no expert, but I've dozens of PostgreSQL databases running mostly
> without manual maintenance for years.
>
> Ya, I've sort of had the same experience with PG DBs.  Like the
> everready bunny, they just keep on running.  But these workstations
> are pretty volatile as they keep overloading them and crash them.  Of
> course any DB running would die too and have to be
> restarted/recovered.  So the place for  the DB is really elsewhere, on
> an external server that wouldn't be subject to this volatility and
> crashing.  I told him about transactions and how you could prevent
> partial writing of data sets.
>
> So far, I'm not hearing of anything that looks like a solution given
> the constraints he's put on this.  Don't get me wrong, he's a very
> smart and sharp software engineer.  Very smart.  But for some reason,
> he doesn't like the client/server DB model which would work so nicely
> here.  I'm just trying to make sure I didn't miss some sort of
> solution, PG or not, that would work here.
>
> Thanks for your interest and input everyone !
>
>
>
>
> On Fri, Aug 24, 2018 at 2:39 PM Edson Carlos Ericksson Richter
> <richter(at)simkorp(dot)com(dot)br <mailto:richter(at)simkorp(dot)com(dot)br>> wrote:
>
> Em 24/08/2018 15:18, David Gauthier escreveu:
> > Hi Everyone:
> >
> > I'm going to throw this internal customer request out for ideas,
> even
> > though I think it's a bit crazy.  I'm on the brink of telling
> him it's
> > impractical and/or inadvisable.  But maybe someone has a solution.
> >
> > He's writing a script/program that runs on a workstation and
> needs to
> > write data to a DB.  This process also sends work to a batch
> system on
> > a server farm external to the workstation that will create
> multiple,
> > parallel jobs/processes that also have to write to the DB as
> well. The
> > workstation may have many of these jobs running at the same
> time.  And
> > there are 58 workstation which all have/use locally mounted
> disks for
> > this work.
> >
> > At first blush, this is easy.  Just create a DB on a server and
> have
> > all those clients work with it.  But he's also adamant about having
> > the DB on the same server(s) that ran the script AND on the locally
> > mounted disk.  He said he doesn't want the overhead,
> dependencies and
> > worries of anything like an external DB with a DBA, etc... . He
> also
> > wants this to be fast.
> > My first thought was SQLite.  Apparently, they now have some
> sort of
> > multiple, concurrent write ability.  But there's no way those batch
> > jobs on remote machines are going to be able to get at the locally
> > mounted disk on the workstation. So I dismissed that idea. Then I
> > thought about having 58 PG installs, one per workstation, each
> serving
> > all the jobs pertaining to that workstation.  That could work. 
> But 58
> > DB instances ?  If he didn't like the ideal of one DBA, 58 can't be
> > good.  Still, the DB would be on the workstation which seems to be
> > what he wants.
> > I can't think of anything better.  Does anyone have any ideas?
> >
> > Thanks in Advance !
> >
>
> I'm no expert, but I've dozens of PostgreSQL databases running mostly
> without manual maintenance for years, just do the backups, and you
> are fine.
> In any way, if you need any kind of maintenance, you can program
> it in
> your app (even backup, restore and vacuum) - it is easy to throw
> administrative commands thru the available interfaces.
> And if the database get out of access, no matter if it is
> centralized or
> remote: you will need someone phisically there to fix it.
> AFAIK, you don't even PostgreSQL installer - you can run it embed
> if you
> wish.
>
> Just my2c,
>
> Edson
>
>
I think its worth to add, PG or not PG, if the workstation crash, you
will be in trouble with ANY database or file solution you choose - but
with PG you can minimize the risk by fine tunning the flush to disk
(either in PG and in OS). When correctly tuned, it works like a tank,
and is hard to defeat.

Regards,

Edson.