misc on The Lars Breddemann Blog

Advanced Database magic with Tableau

Tue, 30 Dec 2025 04:44:36 +0000

Some time ago I needed a way to control how long a database query would (at least) take. The purpose for this was to test out timeout behaviour of components that trigger and wait for the query result.
While the specifics of this testing purpose are not really that interesting, I learned quite a bit while implementing my " wait for a query as long as I like" solution.

Three small wins

Sun, 21 Dec 2025 11:11:19 +0000

One of the aspects of home computers like the C64 or the Amiga 500 that made them so interesting to me - well behind gaming of course - was that those machines were something one could know well.
It was possible to know those things well enough to use, to program, to take apart, to fix, and to modify them.

Tableau Loops

Wed, 10 Dec 2025 05:41:45 +0000

The data visualisation tools Tableau Server and Tableau Cloud are well known - in the circles that use such tools - for the broad range of ways data can be made into a picture. Dashboards can be built from many fundamental chart types, arranged, formatted, made interactive, linked into other systems. The options are vast and sites like Tableau Public show off what talented analysts and designers can pull off with those tools. Have a look, it is truly amazing how data can be presented with Tableau.

PostgreSQL DB restore lite

Thu, 10 Apr 2025 13:26:06 +0000

Tableau Server, for those not familiar with it, is a system for creating, managing, and sharing visual analytics and all the things that go into it. While users can create data sources and visualisation workbooks, just like with the O.G. Tableau Desktop application, Tableau Server does many things beyond that. It is a full-blown web application server that can be programmed and that collects and keeps a lot of data about how it is used.

Tying off a loose end in TRON

Sun, 17 Mar 2024 08:42:18 +0000

Tying off loose ends can be very satisfying. When the detective eventually reveals the crucial connection between facts that have been out in the open the whole time and is finally able to name the killer: amazing. That’s literally what suspense crime dramas are made for. Or, in my line of work, rarely is something so capable of turning a good day into a great one than fully understanding some otherwise inexplicable misbehaviour/failure/bug of the system you’re working on. It’s all about having all important puzzle pieces in sight and then connecting them in the right way. Here is one of those connections that I was only able to make years after having seen all the pieces — multiple times.

Moving Backups from AWS S3 to Backblaze

Sun, 18 Feb 2024 04:57:00 +0000

Working in professional and corporate IT means there is a lot of planning, testing, and review happening. Costs are to be predicted, risks to be identified and evaluated, and project plans need to be laid out ahead of time. This slows down progress but should help with preventing major IT disasters. Not so with personal IT: manuals are rarely consulted; infrastructure changes happen ad-hoc and the functioning of programs and systems is learned while using them.

Tableau repository schedules decoded

Fri, 04 Aug 2023 07:55:06 +0000

Something (hopefully useful) for the all the Tableau repository warriors:
Table schedules holds, as the name implies, the definition of schedules in Tableau Server.
Unfortunately for the SQL user, the information about which day of the week and which day of a month a schedule should trigger an action are encoded in two number columns via binary encoding.
So, e.g. if the right-most bit of the value in day_of_week_mask is set, then this schedule triggers stuff on a Sunday.

Answers Pinboard

Mon, 19 Dec 2022 04:33:45 +0000

Apart from writing blog posts I have written answers to many questions on several Q&A sites like StackOverflow and SAP Community. Some of those answers received good feedback and/or the answer surprised me once I worked it out.

Using a Mac still comes with some pleasant surprises

Sat, 22 Oct 2022 03:50:12 +0000

Recently we got a new Macbook in our household, seeing that the previous one was from 2013 and would not allow new versions of macOS to be installed. Part of setting up the new laptop is to move all data from the old one onto it. This is a solved problem, you might say, and you are right: it is.

Write better SQL!

Sat, 03 Apr 2021 07:40:46 +0000

When reading Some opinionated thoughts on SQL databases recently, I felt reminded of an observation that I have made in the past: the way SQL is commonly used and presented is way too low-level.

Have yourself a good 🙂🕰! (😎)

Sat, 20 Feb 2021 07:17:41 +0000

Ok, nothing complex, crazy, or high-concept today. Just a reminder that stuff like the following is possible without any effort with your database of choice (including HANA, of course):

This does not stop if you want to dig into query performance. This is what the EXPLAIN PLAN looks like:

DBeaver log files: beware and free up disk space

Wed, 04 Nov 2020 06:50:02 +0000

Remember my post from earlier in April 2020? (Getting data into HANA - the easy way)

In it, I described how to use DBeaver to load CSV files into HANA quick and hassle-free. For DBeaver activities like importing or exporting data are so-called Database Tasks. For every execution of a task, DBeaver keeps a log file and these log files can be easily accessed via the Database Tasks Eclipse View:

macOS Excel - clear recently used files list

Thu, 15 Oct 2020 02:43:46 +0000

Ok, long story short: MS Excel on macOS has a list of recently used files. This list holds up to 25 entries and keeps every Excel file you open.

And there is no option to clear it or to disable it.

How to engineer your DB code

Mon, 05 Oct 2020 00:25:17 +0000

A journey of 1000 miles… #

We are developers. We make the modern world tick and create tools for information workers. We are computer scientists, IT experts, and coders, and we call ourselves engineers. We even renamed a part of our industry “software engineering” to get one step closer to this aspirational goal of being professionals when doing our jobs.

What a 10x network speed difference looks like

Mon, 21 Sep 2020 02:54:49 +0000

One of the side-effects of working from home a lot - with or without a pandemic running wild - is that the residential IT equipment gets better.

Where the WIFI provided by the cable-modem-combi-device was “fine” initially, a “mesh”-system is now the acceptable minimum. I know people that go all-in and just plain hardwire every device considered to be important (looking at you, Playstation…).

Getting data into HANA - the easy way

Fri, 04 Sep 2020 04:45:21 +0000

In a recent blog post SAP presented several ways to load data into a HANA instance. The main approach shown was to use a combination of Python, SQLAlchemy, and Pandas (a Python data analysis library) as well as the Python-specific version of the SAP HANA client driver.