This repo contains necessary tools to wrap "xxhash" hashing library as a mysql plug in and use xxhash library as a user defined function in MySQL.

See this Stackoverflow Question for further details.

Note: xxhash_mysql_plug_in does not install dependencies such as libmysqlclient or mysql-server or anything like that.

In order to compile the library make sure gcc, g++, libmysqlclient-dev and make tools installed on your system.

Install required tools for compiling the plug (for debian based distributions).

$ sudo apt install make
$ sudo apt install gcc
$ sudo apt install g++
$ sudo apt install libmysqlclient-dev

Note: If you need to install this plug in to non-debian based distributions, please update the paths in the Makefile to match with mysql path in your system.

Compiling:

$ make #creates mysqlxxhash.so in the local folder, you can copy it to mysql plugin directory manually.
$ make install #creates mysqlxxhash.so and installs it to /usr/lib/mysql/plugin directory.

You can register this function manually with this way:

$ mysql -uroot -p<PASSWORD> <DB> -e "CREATE FUNCTION xxhash RETURNS INTEGER SONAME 'mysqlxxhash.so'"

DB parameter is optional. If you omit it, then this function will be available for all databases served by your particular instance of MySQL.

To drop the function run:

$ mysql -uroot -p<PASSWORD> <DB> -e "DROP FUNCTION xxhash"

(again DB parameter is optional)

After installing plugin you can run use the xxhash function in your select statements.

Mysql call	Python xxhash library call for cross check

Disclaimer1: xxHash is an extremely fast non-cryptographic hash algorithm, working at speeds close to RAM limits. It is proposed in two flavors, 32 and 64 bits. The algorithm is developed by Yann Collet(@Cyan4973)

Disclaimer2: xxhash64.h is a library which contains xxhash implementation of Yann Collet's xxHash64 algorithm. This library developed by Stephan Brumme Also see Stephan Brumme's explanation of xxhash algorithm