Recently came across a requirement that consisted of a list of items to display which is decorated by a smaller list of colours. The colours were to cycle through and wrap at the end of the list — starting over from the beginning. Mini Challenge 01: Changing Background Colors for Certificates Card Story for the… Continue reading Array wrapping with modulus
Tech Meetups
Tech Meetup Calendar
Rewrite address (To:) of message in postfix’s email queue
If an email gets stuck in postfix’s deferred queue, there are a couple of ways to deal with it.
Mailing List
For general discussion, the “discuss” list:
https://lists.bclug.ca/mailman/listinfo/discuss
Alternately, send an email to discuss-subscribe@lists.bclug.ca, then simply reply to the confirmation email message.
WTF, JS?
I scored 9/28 on https://jsdate.wtf and all I got was this lousy text to share on social media.
https://jsdate.wtf/
PostgreSQL CHECK constraints
When violating a constraint on a specific field, the error shows the field’s name as seen in these examples…
PostgreSQL & JSON
Had some fun exploring JSON and JSONB features in PostgreSQL recently.
First task was to flatten two tables’ rows into a single field of JSON data. Nice intro to json_agg() and row_to_json().
Where it got real fun was extracting that data back out from JSON to rows & columns with the help of jsonb_path_query().
LATERAL JOINs in PostgreSQL
The topic of JOINs was thoroughly covered (JOINs are old news), but one user (Mani) made this comment: I have gone through videos, but lateral join concept is missing. Please update course with lateral join and use case. This prompted a digression into LATERAL JOINs as it was a new thing to me. My reply… Continue reading LATERAL JOINs in PostgreSQL
\gexec in PostgreSQL
\gexec in PostgreSQL is handy when running a function that outputs dynamically generated SQL to be run to get final results
Numeric column names in PostgreSQL
In the Udemy PostgreSQL Bootcamp : Go From Beginner to Advanced, 60+hours course, there was a lesson where we wrote a function to output some SQL to enable dynamic pivot tables:pass the table_name, vertical_header_column, horizontal_header_column, value_column, and data_type and any table can be “pivoted”. Pretty nifty. But… it was hideously difficult to transcribe the code… Continue reading Numeric column names in PostgreSQL
PostgreSQL Pivot Tables
PostgreSQL Pivot Tables using \crosstabview with sortation based upon various criteria
systemd & resource monitoring
I found a nifty trick for measuring the resource consumption of various services using systemd. This was while trying to gauge the differences between Mailman v2 and Mailman v3 resource management. I have ranted about how much more expensive MM3 is in resource consumption (basically, about ¾ of a 2GB RAM VPS is consumed). I… Continue reading systemd & resource monitoring
Email lists with Mailman3
Is migrating from Mailman2 to Mailman3 too much of an ordeal?
Is it worthwhile?
Does Mailman3 consume too many resources?
Deploying React Apps
When deploying React apps on Apache or nginx, in a sub-folder of the root / DocumentRoot, there are some issues to consider. While the deployment guide suggests setting “homepage”: “.” in package.json, others have advised against this. Taking that at face value, I used “homepage”: “/react/react-hooks”, which initially appeared to work. However… static images from… Continue reading Deploying React Apps