Tips

How to install and use pgindent

pgindent maintains the uniform layout style of postgresql related source code.


My first Chinese book

My first Chinese book has been published on 1st June.


How to calculate A * B mod N, where numbers are 64 bit integers

I made a program to calculate ‘A * B mod N’, where A, B and N are 64 bit integers.

Main problem is to avoid overflow when calculate ‘A * B’.

I searched a while and finally decided to use the interleaved modular multiplication method, which is used in the feild of electric circuit design.

I found some bugs when I tested corner cases, so I have to fix them [2018.9.2]. I think I’ve fixed them [2018.9.3]. I’ve just improved it! [2018.9.5]

The program is shown below:


Blind-Deblurring System

At the end of 2014, I was shocked at the progress of blind deblurring algorithm, so I studied the recent researches in this field.

I read many papers and made a system based on this paper: “Blind deconvolution using alternating maximum a posteriori estimation with heavy-tailed priors”.


Customized Statistics Views in PostgreSQL

I always use my customized statistics views shown below because the original ones provide only minimum information.

I show my tools in this post.


CentOS with GNOME desktop on Vagrant

I made a CentOS vagrant box which contains GNOME desktop environment, so I will show how to use and to make it.


How to relocate tablespace directory

I’ll demonstrate how to relocate a tablespace directory without the reconstruction of databases.