Re: unorthodox use of PG for a customer

On 08/24/2018 12:07 PM, David Gauthier wrote:
> 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.

Then a SQLite db per work area and as part of the batch rsync db file to 
remote server, do work on external server, rsync back to work area.

> 
>  >>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@simkorp.com.br <mailto:richter@simkorp.com.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
> 
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com