markdanese

# load libraries --------------------------------------------------------------------

library(data.table)
library(feather)

# US Part D Drug prices 2013: 500 MB zip, 2.9 GB uncompressed -----------------------

pde_link <- "http://download.cms.gov/Research-Statistics-Data-and-Systems/Statistics-Trends-and-Reports/Medicare-Provider-Charge-Data/Downloads/PartD_Prescriber_PUF_NPI_DRUG_13.zip"
tf <- tempfile()

oseiskar

library(data.table)
library(microbenchmark)

performanceTest <- function (nrows=100000, ncols=400, quote=TRUE, col.type='character') {
  
  message(paste0('generating test table, col type ', col.type))
  x <- c(1:nrows)
  dt <- data.table(col1=x)
  
  col_generators = list(

daroczig

## original idea & report by Henrik Bengtsson at
## https://stat.ethz.ch/pipermail/r-devel/2016-February/072388.html

## This script downloads the list of currently published R packages
## from CRAN and also looks at all the archived package versions to
## combine these into a list of all R packages ever published on
## CRAN with the date of first release.

## CRAN mirror to use
CRAN_page <- function(...) {

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD