How to manage schema migrations (track database changes)

A list. Alternatives to the popular/enterprise options:

• DBIx::Class::Migration - Perl. works but fiddly

• App::JESP - Perl. Simpler

• Flyway - popular

• Liquibase - popular

• MyBatis migrations - popular

• DBDeploy - popular

• Active Record Migrations - Ruby?

• Squitch - standalone

• Skeema - stands out

How to correctly use full screen notifications in Android

Developers, don't break UI guidelines, you insensitive clods!

Full-Screen Intent Notifications — Android | by Giorgos Neokleous | AndroidPub | Medium

https://medium.com/android-news/full-screen-intent-notifications-android-85ea2f5b5dc1

Notification.Builder  |  Android Developers

https://developer.android.com/reference/android/app/Notification.Builder#setFullScreenIntent(android.app.PendingIntent,%20boolean)

Display time-sensitive notifications  |  Android Developers

https://developer.android.com/guide/components/activities/background-starts

How to use mysqldump

 I heard you like mysqldump so I ran mysqldump:

Escape quotes correctly for looping over nested ssh commands

$ for server in $(cat servers); do echo $server $(ssh -A user@bastion "ssh -q -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no $server \"/bin/bash -c \\\"which mysqldump\\\"\" "); done

Output:

foo-2 /usr/bin/mysqldump

bar-4 /usr/bin/mysqldump

baz-12 /usr/bin/mysqldump

qux-3 /usr/bin/mysqldump

quxx-4 /usr/bin/mysqldump

MySQL explain plan cheat sheet

Explanation of explain output:

• select_type: SIMPLE/SUBQUERY/UNION/DERIVED
• partitions: NULL ??
• type: (from worst to the best): ALL, index, range, ref, eq_ref, const, system
• possible_keys: food,bar,baz,id (good)
• key: foo(good)
• key_len: 334 ??
• ref: const,const,const ??
• rows: 1 (lower is better. must be less than total rows)
• filtered: 100.00 (lower is better, but only used if there's a join)
• Extra: NULL

Bad extra values:

• using where
• using temporary
• using filesort

Good extra values:

• using index