nghoapc / til Goto Github PK

Why?

• 16384 is a Power of Two

• Currently, Power of Two are the only known Almost perfect numbers.

• In Computer Science, Powers of two are beautiful numbers

  Said by someone famous

• Using Power of Two is make color, make you feel more pro

Selected powers of two(Hằng đẳng thức đáng nhớ)

• = 256:
  The number of values represented by the 8 bits in a byte.
• = 1 024:
  The binary approximation of the kilo-, or 1,000 multiplier, which causes a change of prefix. For example: 1024 bytes = 1 kilobyte.
  This number has no special significance to computers, but is important to humans because we make use of powers of ten.
• = 4 096:
  The hardware page size of an Intel x86-compatible processor.
• = 32 768:
  The number of non-negative values for a signed 16-bit integer.
• ......

So?

• You need to partition your hard drive:
  200Mb? No. Use 256Mb
• You need define your password:
  123123123? No. Use 18446​744​073​709​551​616

Ref:

• Power of Two
• Almost perfect numbers

https://www.gnu.org/software/coreutils/manual/coreutils.pdf
https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.pdf

Why?

• Adding Syntactic Sugar to Make Rails Service Objects Suck Less

• If only there were precedence in Ruby for calling something and having it execute itself immediately with the given parameters… oh wait, there is! It’s Proc#call

What's Proc#call ?

• Invokes the block, setting the block's parameters to the values in params using something close to method calling semantics. Returns the value of the last expression evaluated in the block.
• Note that proc.() invokes proc.call() with the parameters given. It's syntactic sugar to hide “call”.
• For procs created using lambda or -> () an error is generated if the wrong number of parameters are passed to the proc. For procs created using Proc.new or Kernel.proc, extra parameters are silently discarded and missing parameters are set to nil.

Ref:

Ruby's Eigenclass
Rails Service Objects: A Comprehensive Guide
Proc#call

https://shekhargulati.com/2022/07/08/my-notes-on-gitlabs-postgres-schema-design/

• Issue while building docker image with ruby:2.5.3:

W: The repository 'http://deb.debian.org/debian stretch Release' does not have a Release file.
W: The repository 'http://deb.debian.org/debian stretch-updates Release' does not have a Release file.
W: The repository 'http://security.debian.org/debian-security stretch/updates Release' does not have a Release file.
E: Failed to fetch http://deb.debian.org/debian/dists/stretch/main/binary-amd64/Packages  404  Not Found
E: Failed to fetch http://deb.debian.org/debian/dists/stretch-updates/main/binary-amd64/Packages  404  Not Found
E: Failed to fetch http://security.debian.org/debian-security/dists/stretch/updates/main/binary-amd64/Packages  404  Not Found

• Root cause:
  stretch was removed from http://security.debian.org/debian-security/dists/
• Workaround:
  Touch etc/apt/archive_sources.list

deb http://archive.debian.org/debian stretch main
deb http://archive.debian.org/debian-archive/debian-security stretch/updates main

Then:

FROM ruby:2.5.3 AS builder
COPY etc/apt/archive_sources.list /etc/apt/sources.list

1 quintillion is equal to 1000000000 billions

Loods good to me

Be sure to ignore the column
Add to models/model.rb

def self.columns super.reject { |c| ["<column_name>"].include?(c.name) } end

Ref: https://github.com/ankane/strong_migrations#removing-a-column