Ben Chuanlong Du's Blog

It is never too late to learn.

Install ITypescript/IJavascript for Jupyter Notebook

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

https://github.com/nearbydelta/itypescript

https://github.com/n-riesco/ijavascript/

wajig install nodejs npm
sudo ln -s /usr/bin/nodejs /usr/bin/node

sudo npm install -g itypescript
sudo its --hide …

Building Tool for Scala

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. The recommended building tool for Sclas is Gradle > Maven > sbt. Maven is too verbosal while sbt is too hard to use.

References

http://www.hammerlab.org/2017/04/06/scala-build-tools/

Spcify Java Version to Use in a Scala Project

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

javacOptions ++= Seq("-source", "1.8", "-target", "1.8", "-Xlint")

initialize := {
  val _ = initialize.value
  if (sys.props("java.specification.version") != "1.8")
  sys.error("Java 8 is required for this project …

Collection of Jupyter Notebooks

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

https://github.com/jupyter/jupyter/wiki/A-gallery-of-interesting-Jupyter-Notebooks

https://blog.dominodatalab.com/lesser-known-ways-of-using-notebooks/

https://www.opendatascience.com/blog/jupyter-zeppelin-beaker-the-rise-of-the-notebooks/

String in SQL

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Teradata

regexp_instr REGEXP_LIKE REGEXP_REPLACE REGEXP_SUBSTR

  1. trim trim specified pad characters or bytes from a character or byte string

  2. like %, _ like, case-insensitive You can also like any (pattern_1, pattern_2, ...) like all …

Primary Key vs Index in SQL

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. index is for distribution data index does not have to be unique

  2. primary key must be unique and non null

  3. primary keys are automatically indexed