spark join的区别

http://apachesparkbook.blogspot.com/2015/12/join-leftouterjoin-rightouterjoin.html
https://stackoverflow.com/questions/40772209/how-to-replace-null-to-0-in-left-outer-join-in-spark-dataframe-v1-6

更改mac默认python的办法

问题：
Fatal Python error: PyThreadState_Get: no current thread

解决方法
https://stackoverflow.com/questions/15678153/homebrew-python-on-mac-os-x-10-8-fatal-python-error-pythreadstate-get-no-cu

sudo port select --list python

For my computer, it showed:

Available versions for python:
none
python25-apple
python26
python26-apple
python27 (active)
python27-apple

in which python27(by Macport) was currently active. Then,

sudo port select python python27-apple

评价指标

ndcg
https://blog.csdn.net/u011926899/article/details/52669180

R语言代理设置

Sys.setenv(http_proxy="http://user:password@proxy_server:port")

目前上述方式是比较有效的方法，即直接在console中进行代理的设置
具体参照 https://support.rstudio.com/hc/en-us/articles/200488488-Configuring-R-to-Use-an-HTTP-or-HTTPS-Proxy
https://support.rstudio.com/hc/en-us/community/posts/204007027-How-to-use-proxy-in-RStudio-on-Mac-OS-X-Yoesmite-

hive 一坑记录

Caused by: java.util.regex.PatternSyntaxException: Unclosed character class near

https://stackoverflow.com/questions/21816788/unclosed-character-class-error

virtual box 内网银使用

http://www.sijitao.net/618.html
https://www.virtualbox.org/wiki/Download_Old_Builds virtual box 历史的pack可以从这里下载

intellij idea 快捷键

1.搜索文件搜不到，如eva.js能看见，但是找不到
参考https://stackoverflow.com/questions/13685036/how-can-i-find-particular-file-in-intellij-idea