Re: [gentoo-user] postgresql 9.5.2 versus Gentoo wiki install instructions?

[J. Roeleveld]

On Saturday, May 21, 2016 06:51:46 AM Alec Ten Harmsel wrote:
> Joost knows far more about databases than I do, so I mostly commented on
> the workflow part.
>
> On 2016-05-20 22:36, waltdnes@××××××××.org wrote:

<snipped>

> I have never run postgresql on gentoo (hopefully soon :D), but on
> Debian-derived distros and RPM-based distros, PGDATA is always somewhere
> in /var. /etc seems wrong.

There are symlinks from the /var location to /etc for the configuration files.
The data itself, eg. PGDATA, sits, by default, in /var/.....

<snipped>
> `equery use gnumeric' gives the `libgda' flag, which should pull in
> database support. I've never used it, so I don't know whether or not it
> works/how well it works. What is in this spreadsheet? If it is financial
> stuff, you can use Gnucash, which supports using a database as a backend.

Does this finally work?
Last time I tried this, half the functionality didn't work at all and the 
other half was buggy. (This was years ago)

> >    My main problem is that columns of several thousand rows are functions
> >
> > based on other columns of several thousand rows.  For the time-being,
> > I've split up the spreadsheet into a few pieces, but a database is the
> > best solution.  If I could run the calculations in the database, and
> > pull in the final results as static numbers for graphing, that would
> > greatly reduce the strain on the spreadsheet.  Or is it possible to
> > graph directly from postgresql?
>
> Here are my recommendations, in order of "least code" to "most code" (I
> don't think postgresql supports graphing):
>
> 1. Write some sql scripts that compute the data you need and output CSV,
> then import to Gnumeric and do the plots.

For script examples:
http://stackoverflow.com/questions/1517635/save-pl-pgsql-output-from-postgresql-to-a-csv-file

> 2. Write python script(s) that run SQL commands and plot the data with
> matplotlib.
> 3. Write a webapp so you don't have to run scripts by hand - the plots
> are generated by opening a web page.
4. Write it all in C++ :)

> Depending on how much automation you want vs. how much time you want to
> spend writing/debugging code, hopefully one of those helps. I help
> researchers use a HPC cluster; some are very savvy programmers, some are
> not. For working on "big data" projects, some will throw raw data into a
> Hadoop cluster and happily do all their work using Hadoop, while some
> will put in raw data, clean it up, and then pull it out and use MATLAB,
> stata, R, etc., so you just need to find the workflow that works best
> for you. I personally would choose option 3, as it involves the least
> amount of running scripts over and over, but to each his own.
>
> I have actual free time now (done with school, finally), so I might be
> able to help prototype if you would like as well.

Something I could use (and others):
A simple PHP page which I can feed:
- connection parameters to a database
- select-query
- which result-field to use for the horizontal axis
and then plots the remaining fields for the vertical axis.

I haven't checked with google yet, so if there is a decent example, I'd be 
interested :)

--
Joost