cabecada

SELECT *
FROM (
   SELECT
   (
	SELECT concat('Marie-', string_agg(x,'-'))  as name_first_female
	FROM (
		select start_arr[ 1 + ( (random() * 100)::int) % 32 ]
		FROM
		(
		    select '{Claude,Thérèse,Géraldine,Sylvie,Sophie,Solange,Vivianne,Cunégonde,Albertine,Charlotte,Caroline,Célestine,Bérangère,Sylvianne,Alphonsine,Claire,Françoise,Chantal,Geneviève,Christine,Louise,Adeline,Céleste,Angélique,Clothilde,Jeanne,Pierre,Valentine,Paule,Noëlle,Lise,Cécile}'::text[] as start_arr

cabecada

select
  test,                                                                   
  query::char(48),
  instance,
  --scale,
  --clients,
  round(mean_time::numeric, 4) mean_time,
  round(stddev_time::numeric, 4) stddev_time,
  round(((mean_time - mean_time_lag)::numeric / mean_time::numeric )*100, 1) as mean_time_diff,
  round(((stddev_time - stddev_time_lag)::numeric  / stddev_time::numeric )*100, 1) as stddev_time_diff

cabecada

Resize a Hard Disk for a Virtual Machine

Our Virtual Machines are provisioned using Vagrant from a Linux base box to run using VirutalBox. If the Hard Disk space runs out and you cannot remove files to free-up space, you can resize the Hard Disk using some VirtualBox and Linux commands.

Some assumptions

The following steps assume you've got a set-up like mine, where:

cabecada

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

cabecada

#MongoDB 3.2.x Sharding Sharding is used when the database is too large to run on a single server and you need to spread the load across multiple servers. The name itself refers to the breaking (sharding) of the data into seperate groups of data which will reside on different servers.

##Configuration Server Start the server on your server (myserver0)

mongod --configsvr --dbpath /data

On myserver1 start the shard giving the configuration server as the --configdb option

cabecada

Set up Django, Nginx and Gunicorn in a Virtualenv controled by Supervisor

Steps with explanations to set up a server using:

• Virtualenv
• Virtualenvwrapper
• Django
• Gunicorn

cabecada

source :rubygems
gem "puma"
gem "sinatra"