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test luasql's postgresql driver performance (not better than pgbench)

test luapgsql driver performance (vs pgbench)

Lua 5.1 Use luadbi connect to postgresql

test luadbi's postgresql driver performance (vs pgbench)

array variable used in printf function

array of arrays vs array of pointers

fgets vs scanf

arguments and options and optarg in C

type sizeof: char, short, int, long, float, double and prefix unsigned, long

C compilation behind the scenes

include custom head file

Makefile usage

flex length type in struct

struct vs array

function's argument is function's local variable, build in stack memory, released when function exit. its value copyed from out variables.

struct vs union

bit-field

function name address vs array name address

struct use case - linked lists

Use the heap for dynamic storage

char * a, char ** a, char * a[], char a[][], char * a[][], char ** a[][], char * a [][][], and so on in memory

execute copyed function code : Segmentation fault

qsort

variable number of arguments function

static and dynamic libraries

fork() and vfork() getppid's result

use setitimer raise signal interval-granuated by seconds and microseconds

Interprocess communication - 1 data stream

pipe q&a

use setitimer raise signal interval-granuated by seconds and microseconds

Interprocess communication - 2 signal handler

wake-up signal SIGALRM from alarm() or setitimer(). SIG_DFL & SIG_IGN

socket programming example

PostgreSQL hung case

lseek, fallocate来快速创建一个空洞文件，lseek不占用空间，fallocate占用空间(快速预分配)。

从fread和mmap 谈读文件的性能

sync_file_range - sync a file segment with disk (None of these operations writes out the file's metadata)

#pragma GCC diagnostic push | pop

llvm, clang

PostgreSQL integration with pg_matlab

What's the best MATLAB equivalent? (open source or otherwise free)

pg_matlab v2 install

MATLAB 2013a connect to postgresql use jdbc

用PostgreSQL了解一些统计学术语以及计算方法和表示方法 - 1

曾国藩的"顺势而为"在PostgreSQL中的价值体现

首选来个线性回归分析linear regression, 最小二乘法least-squares-fit的小故事(取自百度) : 1801年，意大利天文学家朱赛普·皮亚齐发现了第一颗小行星谷神星。经过40天的跟踪观测后，由于谷神星运行至太阳背后，使得皮亚齐失去了谷神星的位置。

SAS vs. R (vs. Python) – which tool should I learn?

Covariance matrix 矩阵协方差计算方法

在R中, 我们要计算一组数据的秩, 可以使用rank函数.

scale in R

R help