Re: Design ? table vs. view?

On Tue, Jul 15, 2014 at 8:46 AM, David G Johnston <
david(dot)g(dot)johnston(at)gmail(dot)com> wrote:

> John McKown wrote
> > I have a table which has some "raw" data in it. By "raw", I mean it is
> > minimally processed from a log file. Every week, I update this table by
> > processing the weekly log using awk to create a "psql script" file which
> > looks similar to:
> >
> <snip>
> > So the overhead may be quite high, because to SELECT from RUNINFO,
> > PostgreSQL must realize all four views.
> >
> > I appreciate your thoughts on if this is OK, given that performance is
> > currently acceptable. Mainly because this work is basically only done one
> > a
> > week, on Sundays. And I don't do it myself, it is done via a scheduler
> > (not
> > cron, but similar) which runs some scripts.
>
> I would likely make "jobrun.runinfo" into a table while leaving
> "jobrun.rawdata" as-is. I would have a function that populates "runinfo"
> from "rawdata" that I would call after performing the copy to "rawdata".
> There would be no views - unless you desire a view interface over "runinfo"
> for API or permission reasons.
>
> In 9.4 you can (probably) make "runinfo" an explicit MATERIALIZED VIEW and
> perform REFRESH command to accomplish the same thing - though I am not
> particularly familiar with the mechanics of that feature.
>
> David J.
>
>
Being the indecisive nut that I am, I am going to do both <grin/>. I will
keep the current view. But when I update the rawdata, what I will then do
is:

drop table runinfo_table;
create table runinfo_table as select distinct * from runinfo;

I am fairly confident that there cannot be any duplicates in runinfo. But,
being paranoid as well, I will do the DISTINCT just to be sure. I may
change the VIEW to do that in the future, and remove it from the
preceeding. Since the process which updates the rawdata table is automated
and runs on a Sunday, the time needed to recreate runinfo_table is not
relevant to me. So I get what I want, unless I update rawdata off schedule.
I cannot imagine why I would do that since the logs from which I create it
are generally only available after 17:00 local time on Sunday. Getting the
iogs-to-date information for the time since the last dump is basically a
PITA and my current use is not critical. Actually, it is more a
"skunkworks" project of my own to produce a set of nice graphs, using R,
which _might_ turn out to be interesting to management, but the production
of which _will_ help me learn PostgreSQL and R better (hopefully).

Many thanks.

--
There is nothing more pleasant than traveling and meeting new people!
Genghis Khan

Maranatha! <><
John McKown