https://blog.svedr.in/enSun, 15 Feb 2026 11:29:07 GMTNikola (getnikola.com)http://blogs.law.harvard.edu/tech/rsshttps://blog.svedr.in/posts/migrating-from-sqlite-to-mariadb/Svedrin<div><p>Here’s a clean way to migrate an SQLite DB to MariaDB.</p> <p><a href="https://blog.svedr.in/posts/migrating-from-sqlite-to-mariadb/">Read more…</a> (1 min remaining to read)</p></div>databaseshttps://blog.svedr.in/posts/migrating-from-sqlite-to-mariadb/Sun, 28 Dec 2025 14:31:07 GMThttps://blog.svedr.in/posts/repmgr-quick-start/Svedrin<div><p>Dear future self, this is a little copy-and-paste tutorial on how to get postgres replication running using repmgr.</p> <p><a href="https://blog.svedr.in/posts/repmgr-quick-start/">Read more…</a> (4 min remaining to read)</p></div>databaseslinuxhttps://blog.svedr.in/posts/repmgr-quick-start/Thu, 22 Sep 2016 18:44:23 GMThttps://blog.svedr.in/posts/calculating-percentiles/Svedrin<div><p>One thing I've been wanting to do for quite some time now is calculating a confidence interval for the metrics measured by Fluxmon. I still have to figure out whether or not it's the same thing, but for starters I'd like to calculate percentiles for those values.</p> <p><a href="https://blog.svedr.in/posts/calculating-percentiles/">Read more…</a> (4 min remaining to read)</p></div>databasesmonitoringhttps://blog.svedr.in/posts/calculating-percentiles/Fri, 21 Aug 2015 09:40:49 GMThttps://blog.svedr.in/posts/discrete-derivative-revisited-how-to-get-dt/Svedrin<div><p>In the <a class="reference external" href="http://blog.svedr.in/posts/discrete-derivative-over-time-series-data-using-postgresql.html">last post</a>, I calculated the discrete derivative of a counter variable's measurements, and I took the short cut by dividing the value's difference — that is, <code class="docutils literal">dx</code> — simply by <em>300</em> instead of calculating the correct value of <code class="docutils literal">dt</code>. This obviously needs to be fixed.</p> <p><a href="https://blog.svedr.in/posts/discrete-derivative-revisited-how-to-get-dt/">Read more…</a> (3 min remaining to read)</p></div>databasesmonitoringhttps://blog.svedr.in/posts/discrete-derivative-revisited-how-to-get-dt/Thu, 20 Aug 2015 14:12:29 GMThttps://blog.svedr.in/posts/discrete-derivative-over-time-series-data-using-postgresql/Svedrin<div><p>I use FluxMon to query statistics from the inverter hooked up to our solar collectors. One of the values the inverter spits out is today's energy production in <em>Wh</em>. This value is reset every day and counts up to a certain value. Fair enough, but I'd be way more interested in the derivative of that value, which would give an indication of how much power is being produced per hour or so.</p> <p><a href="https://blog.svedr.in/posts/discrete-derivative-over-time-series-data-using-postgresql/">Read more…</a> (4 min remaining to read)</p></div>databasesmonitoringhttps://blog.svedr.in/posts/discrete-derivative-over-time-series-data-using-postgresql/Sun, 16 Aug 2015 16:45:51 GMThttps://blog.svedr.in/posts/nifty-queries-over-time-series-data-using-postgresql/Svedrin<div><p>I'm currently looking into loads of maths stuff for <a class="reference external" href="http://fluxmon.de">Fluxmon</a>, so I eventually reached the point where I'd like to try a few things. I've even collected quite a nice amount of data by now, so I have something to go with. But how to store and analyze it?</p> <p>On the Chemnitz Linux Days, Hans-Jürgen Schönig held a talk named <a class="reference external" href="https://chemnitzer.linux-tage.de/2015/de/programm/beitrag/122">PostgreSQL: Daten superschnell analysieren</a> which I had attended, so I wanted to get the data into PostgreSQL and try out some of the fancy stuff he showed. Googling for <em>postgres time series</em>, I stumbled upon <a class="reference external" href="http://no0p.github.io/postgresql/2014/05/08/timeseries-tips-pg.html">this blog post</a> showing a coupl'a nice things too, and since the schema used by this guy is radically simple, I just went ahead.</p> <p><a href="https://blog.svedr.in/posts/nifty-queries-over-time-series-data-using-postgresql/">Read more…</a> (4 min remaining to read)</p></div>databasesmonitoringhttps://blog.svedr.in/posts/nifty-queries-over-time-series-data-using-postgresql/Sun, 16 Aug 2015 15:45:02 GMT