Because technology is never the issue
The main site for Pete McBreen is more formal, this site is for musings and ideas.
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Posted by Pete McBreen 18 Sep 2017 at 19:55
The EFF has resigned from the consortium because Today, the W3C bequeaths an legally unauditable attack-surface to browsers used by billions of people.
Posted by Pete McBreen 04 Feb 2017 at 13:34
An interesting take on the implications of sharing data on Facebook… What should you think about when using Facebook?
We are social animals, and we are wired to want to connect, want approval, want to share, and want to organize on the platform where everyone else is, and this, for now, is in Facebook’s advantage. Additionally, it’s hard to say that Facebook is all bad: it does connect people, it has helped organize meetups and events, and it does make the world more interconnected.
But, as Facebook’s users, we and our data are its product. And, as we understand more about how this data is being used, we can still play on Facebook’s playground, by its rules, but be a little smarter about it.
One amusing part of this article is that it is hosted on github, another social sharing platform. It is as if even tech people find it too much trouble to host their own data.
Posted by Pete McBreen 31 Oct 2016 at 19:42
Finally got around to doing the PostgreSQL version of the ERD generator using GraphViz. This uses the database from the PostgreSQL Tutorial site
As before there is a PostgreSQLERDGeneration.sql query, the resulting DVDRental.gv dot file for graphviz to generate the file and the resulting DVDRental.html. Inline interactive version of the diagram is below.
A few differences
This completes the set of databases that I have made this work for, might include DB2 at some point in the future if I ever work on an IBM system.
For this interactive version, hovering over the lines makes them larger so that you can click to highlight the line. This makes it easy to plan out a query by following the links between the relevant tables, regardless of where they are on the screen. A good example of this would be tracing out which language DVDs are rented out in a specified city? This needs seven tables and six relationships to determine this, and it is much easier to have the path highlighted while writing the query than having to remember the path as you write the query.
Posted by Pete McBreen 02 Oct 2016 at 20:06
Amusing as ever, Derek Lowe’s take on This Compound needs some Hydrogen Peroxide
The experimental section of the paper is worth a read, and again, you can tell that Matzger’s group has good technique because everyone made it intact to the writing of the manuscript. There are pictures of the crystals themselves, which are very nice, until you realize that they’re plotting to blow you into the ceiling crawl space at the first opportunity. It says that “no unplanned detonations were encountered” during the work, which is a nice distinction.
Posted by Pete McBreen 17 Sep 2016 at 22:03
An intriguing presentation on the effects on sea level rise from ice sheet melting, primarily due to the gravitational pull of the large mass of the existing ice sheets
Taking the Fingerprints of Global Sea Level Rise
Spoiler Alert! Next to the ice sheets the sea level can actually fall as a result of the ice melting due to the loss of the gravitational pull from the mass of the ice sheet. It will fall even further over geological times due to the rebound of the crust when the weight of the ice is removed. Canada is rebounding approx. 1mm/yr in response to the removal of the ice sheets from the last ice age.
Posted by Pete McBreen 03 Aug 2016 at 19:45
In every iteration, have a few bugs that do not get fixed. After five or six iterations you can build up a reasonable size bug backlog without even trying, and the best bit is that you can hide them in the previous iterations so nobody important sees them.
Obvious fixes:
Posted by Pete McBreen 18 Mar 2016 at 20:25
This is the same as the Oracle version, but works with SQL Server (tested on SqlServer 2012)
ERDCreationSqlServer-2012-populated.sql
Only problem I’ve identified is that the databases that most need a generated ERD often are lacking in foreign keys that this query uses to identify the relationships…
Posted by Pete McBreen 19 Dec 2015 at 14:46
Recently as part of an archaeology task of understanding how some SQL queries were working, I needed to draw an ERD to help with my understanding of the database. After contemplating drawing the diagram by hand for a few seconds, I decided to leverage GraphViz and just draw a diagram of all of the foreign key relationships between the tables.
Since it was an Oracle database, the queries to read the relationships were not that complex ErdCrearion-specific.sql is designed to run in SQLDeveloper and prompt for the :OWNER tablespace name to pick the tables from, and limit the selection to the names mentioned in the tablelist CTE (unfortunately duplicated as I have not rewritten this to make it simpler).
From that query the output is pasted into the starter GraphViz .gv file scottsimple.gv
digraph ERD {
graph [ rankdir = "LR" ];
ranksep=2;
"SCOTT.DEPT" [ label="<SCOTT.DEPT> SCOTT.DEPT|<PK_DEPT>DEPTNO \l |DNAME \l LOC \l " shape = "record" ];
"SCOTT.EMP" [ label="<SCOTT.EMP> SCOTT.EMP|<FK_DEPTNO>DEPTNO \l |EMPNO \l ENAME \l JOB \l MGR \l STARTDATE \l SAL \l COMM \l " shape = "record" ];
"SCOTT.DEPT":"PK_DEPT"->"SCOTT.EMP":"FK_DEPTNO" [arrowhead = crow];
}
Which after being put through GraphViz
$ dot -Tsvg scottsimple.gv -o scottsimple.svg
gives us a nice image of the relationship. The table name is prefixed with the schema to make sure that you can identify the table correctly for those cases where the same table exists in multiple schemas, and the columns involved in the relationships are highlighted in their own box. The non-relationship columns appear at the bottom of the symbol (column ordering is maintained and hidden columns are not shown).
For a more interactive experience run the SVG file through this converter, svgconverter.rb which converts the SVG file to a HTML file with some D3JS JavaScript that highlights relationships and tables as you click on them - I found that this made it easier to trace through a model when there are 80+ tables.
$ ruby svgconverter.rb scottsimple.svg scottsimple.html
The resulting file when uploaded to a webserver that has d3.js in the right place is interactive - see scottsimple.html unlike the image above it can be clicked on to highlight the symbols or relationships - only the outer line of the table is clickable - the rest is left as an exercise for the reader.
Posted by Pete McBreen 02 Dec 2015 at 20:27
Delving into the archives, Leslie Lamport wrote about the Future of Computing back in 2003. There are still too many programs that are not understood fully by their developers or maintainers.
Posted by Pete McBreen 25 Nov 2015 at 19:01
Somehow or other the Firefox community has convinced itself that scanning add-ons for vulnerabilities and malware is a good idea. Luckily Dan Stillman the developer of Zotero called them out on it pointing out that it is just Security Theater.
Firefox has always had lots of really large extensions, but by deciding that they must be signed and reviewed, the Firefox community has just committed itself to a LOT of extra work reviewing the extensions. Hence the dumb idea of scanning to see if there is anything malicious in it. Now that is an arms race that is going to be lost. The guys in the AdBlock game know that, a continual game of whack a mole. Actively developed extensions like Zotero really lose out because a manual review of a large codebase takes a long time, and scanning is insufficient (as the above link describes, it is easy to create an add-on that passes scanning and does nasty things).
Posted by Pete McBreen 07 Nov 2015 at 15:59
The Atlantic just realized that programmers are not engineers
Sorry to break it to them, but this has been a topic of conversation long before I wrote the book Software Craftsmanship, which was published nearly 15 years ago.
Posted by Pete McBreen 30 Jul 2015 at 13:28
And then this article about testing — Doing Terrible Things To Your Code reminded me to look at it again.
QA Engineer walks into a bar. Orders a beer. Orders 0 beers. Orders 999999999 beers. Orders a lizard. Orders -1 beers. Orders a sfdeljknesv.
I sure wish more programmers would focus a lot of attention on testing their own code before passing it on to QA/Test. That way the QA/Test team can focus on finding the requirements and interaction defects, rather than the simple coding mistakes that are often the bane of their existence
Posted by Pete McBreen 12 Mar 2015 at 19:52
AT LAST, SIR TERRY, WE MUST WALK TOGETHER.
Some quotes from Terry Pratchett
Posted by Pete McBreen 15 Feb 2015 at 18:49
Kevlin Henney - of Curly Bracket Languages fame has a good video of his presentation at a recent NDC conference Seven Ineffective Coding Habits of Many Programmers. As usual a very entertaining talk, but Kevlin is also spot on in identifying ways in which we are lead to make incorrect decisions about the code we are writing.
In it he references a paper from Rob Pike Notes on Programming in C. Although Rob Pike wrote that paper back in 1989 it is still relevant, as can be seen by his words about variable names:
Length is not a virtue in a name; clarity of expression is.
Posted by Pete McBreen 08 Feb 2015 at 13:15
Interesting long article on a Kitchen Bladesmith, describing the expertise that goes into making kitchen knives, especially those for the chef market.
Posted by Pete McBreen 19 Nov 2014 at 21:00
Zed Shaw has written an introduction to his Hard Way series and in it he writes
The one skill that separates bad programmers from good programmers is attention to detail. In fact, it’s what separates the good from the bad in any profession. Without paying attention to the tiniest details of your work, you will miss key elements of what you create. In programming, this is how you end up with bugs and difficult-to-use systems.
Posted by Pete McBreen 11 Nov 2014 at 09:25
In The Leprechauns of Software Engineering Laurent Bossavit has an interesting take on the folklore of software development.
Posted by Pete McBreen 28 Sep 2014 at 19:16
The Beauty of Testing article has a different take on testing;
Test, to put it simply, is the conscience of a product.
Posted by Pete McBreen 01 Jul 2014 at 19:52
Software development is a hard problem.
Books like The Mythical Man Month, Set Phasers on Stun and The Inmates are running the Asylum have all pointed out in their own way that creating software is hard. Fred Brooks focused on the problem of large complex projects, and the problems that face project managers, the other two remind us that even small projects can fail because we still are not able to create software that is both easy to use and powerful enough to do that tasks that we want to do with software.
Until we are able to understand why software development is such a hard problem, we are not going to make much beyond incremental improvement. There will always be a few projects that through the operation of blind luck across millions of projects that results in seemingly reproducible improvement, but the normal regression to the mean will correct that eventually.
Posted by Pete McBreen 29 Jun 2014 at 20:17
I didn’t see this when it was first written, but it matches with my recent experiences.
… most programmers simply don’t know where the quality bar is. They don’t know what disciplines they should adopt. They don’t know the difference between good and bad code. And, most importantly, they have not learned that writing good clean code in a disciplined manner is the fastest and best way get the job done well. – Robert Martin