Type in the exact number of machines to proceed

Post by maynman » Wed, Oct 28, 2020, 3:46 AM UTC

grossvogel wrote: post #246

morelisp wrote: post #178

Earlier quoted context omitted.

A similar tip I picked up long ago: If you're typing a dangerous command, first type a `#` (or `--` if it's SQL, etc.), then the command. Then read it. Then go back to the start of the line and remove the comment and run it.

I always do destructive SQL commands in two steps: first run a select using the WHERE clause you intend to use and verify which records will be affected, then hit the up arrow and edit the beginning of the query leaving the WHERE intact. I also like adding redundant conditions to the WHERE so a typo in any single one of them won't sink me.

Post by mjevans » Wed, Oct 28, 2020, 3:59 AM UTC

tatersolid wrote: post #270

grossvogel wrote: post #246

Earlier quoted context omitted.

I always do destructive SQL commands in two steps: first run a select using the WHERE clause you intend to use and verify which records will be affected, then hit the up arrow and edit the beginning of the query leaving the WHERE intact. I also like adding redundant conditions to the WHERE so a typo in any single one of them won't sink me.

For the rare but critical manual SQL mod our common safety measure is to wrap every DELETE or UPDATE in BEGIN TRAN...ROLLBACK TRAN first. Run on test systems or snapshots multiple times, checking the result inside the transaction. Finally, change ROLLBACK to COMMIT only when you are positive all is well.

Post by justinlloyd » Wed, Oct 28, 2020, 4:24 AM UTC

csmattryder wrote: post #8

I've seen this called "pointing and calling" [1], Japan's train drivers use the technique to force themselves to perform actions and take notice of the current environment. I personally took it to heart, it's a good system for forcing a cache miss in the brain - make sure you're on "database production" or "database localhost" etc. [1] https://en.wikipedia.org/wiki/Pointing_and_calling

Post by greggman3 » Wed, Oct 28, 2020, 4:44 AM UTC

chrisseaton wrote: post #31

roydivision wrote: post #12

Reminds me of the proposal to keep the nuclear launch codes inside the body of an innocent volunteer, so the President would have to kill the person to get the codes. https://boingboing.net/2015/12/11/proposal-keep-the-nuclear-...

I've never understood this idea. If you believe we should never use nuclear weapons, then don't have them at all. If you believe there is a case where it may be moral and rational to use nuclear weapons, why would you want to put a potential barrier in the way of their use? You could have a situation where everyone was agreed to use them but the president was physically unable to harm the aide to use them. You can kn…

Post by tomjakubowski » Wed, Oct 28, 2020, 4:53 AM UTC

PureParadigm wrote: post #240

harikb wrote: post #62

I have a habit of creating cli tools, which potentially do dangerous things, to default to dry-run mode. For example, instead of the typical `--dry-run` or `-n` option, my scripts instead had a cheesy `--do-it` to be non-dry-run. It is annoying as hell to my colleagues, but saved the day many times.

A coworker of mine would write all his bash scripts to echo out the commands it would run, and then to actually run it he would pipe it to bash. This way he could inspect the commands to make sure they were correct before running them. Something like: ./dangerous-script.sh $args | bash