Introduction In this article, we are going to test the MySQL 8 implementation of custom SQL CHECK constraints. Although the CHECK clause is a standard SQL feature, prior to MySQL 8.0.16, the clause was parsed and ignored, so this functionality could only be emulated via BEFORE INSERT and UPDATE triggers. Custom SQL CHECK constraints As I explained in this article, custom SQL CHECK constraints are very useful to ensure non-nullability constraints for JPA entity subclass-specific attributes when using the SINGLE TABLE JPA inheritance strategy. To understand the problem, consider we have the... Read More
Alexei Rodriguez presenting at PLMCE13
During the Percona Live MySQL Community Event this year we had the pleasure of Alexei Rodriguez discussing why Evernote uses Percona’s Private Custom MySQL Training. Alexei is VP of operations there and you can watch a video of his presentation on YouTube.
Alexei said he values having Percona tailor training to their needs, the expert delivery by our practitioner-trainers, and the ability to speak freely about operational issues during private training.
The post …[Read more]
Today, I was looking for a quick way to see HTTP response codes of a bunch of urls. Naturally, I turned to the curl command, which I would usually use like this:
curl -IL "URL"
This command would send a HEAD request (-I), follow through all redirects (-L), and display some useful information in the end. Most of the time it's ideal:
curl -IL "http://www.google.com" HTTP/1.1 200 OK Date: Fri, 11 Jun 2010 03:58:55 GMT Expires: -1 Cache-Control: private, max-age=0 Content-Type: text/html; charset=ISO-8859-1 Server: gws X-XSS-Protection: 1; mode=block Transfer-Encoding: chunked
However, the server I was curling didn't support HEAD requests explicitly. Additionally, I was really only interested in HTTP status codes and not in the rest of the output. This means I would have to change my strategy and issue GET requests, ignoring HTML output completely.
Curl manual to the rescue. A few …[Read more]