sauloperez

NAME="ofn"
DISTRIBUTION="ubuntu"
RELEASE="xenial"
ARCH="amd64"
HOST="ofn.local"

DEVENV_USER="ofn-admin"
DEVENV_GROUP="openfoodnetwork"

PROJECT_NAME="openfoodnetwork"

sauloperez

select spree_line_items.order_id, spree_products.supplier_id, sum(spree_line_items.price * spree_line_items.quantity) AS amount
  from spree_line_items
 inner 
  join spree_variants
    on spree_variants.id                                                           = spree_line_items.variant_id
 inner 
  join spree_products
    on spree_products.id                                                           = spree_variants.product_id
 inner 
  join enterprises

sauloperez

 On Wed, Oct 1, 2014 at 2:18 PM, Stuart Bishop <stuart(at)stuartbishop(dot)net>
wrote:



> It is unnecessary maintaining a list of parameters which require a
> restart, as you can tell by looking at pg_settings.
>
> The way I do it is by comparing the contents of pg_settings with a
> snapshot I made just after (or just before) the server was last

sauloperez

Like most databases, Postgres has a built-in slow query log feature that automatically logs queries to the main Postgres log file if they take over a certain amount of time and it's really easy to set up.

In your main postgresql.conf file (which is often somewhere like /etc/postgresql/9.6/main/postgresql.conf), either edit or add a line like so:

log_min_duration_statement = 1000
After restarting Postgres or reloading the config with SELECT pg_reload_conf();, this directive causes any queries that take over 1000 milliseconds (one second) to be logged.

(The location of the log file varies but is /var/log/postgresql/postgresql-9.6-main.log on my test setup, for instance.)

To deliberately run a long query for testing purposes:

sauloperez

\watch

SELECT datname, usename, query FROM pg_stat_activity; \watch

sauloperez

Bundler could not find compatible versions for gem "actionpack":
  In Gemfile:
    rails (~> 4.0.0) was resolved to 4.0.0, which depends on
      actionpack (= 4.0.0)

    simple_form was resolved to 2.0.2, which depends on
      actionpack (~> 3.0)

Bundler could not find compatible versions for gem "activerecord":
  In Gemfile:

sauloperez

# At the bottom of add /etc/postgresql/9.5/main/postgresql.conf
shared_preload_libraries = 'pg_stat_statements'
pg_stat_statements.max = 10000
pg_stat_statements.track = all

sudo systemctl restart postgresql
sudo su postgres
psql
CREATE extension pg_stat_statements;

sauloperez

ActiveSupport::Deprecation.silenced = true

sauloperez

# Failed
Delayed::Job.where('failed_at IS NOT NULL')

# Active
Delayed::Job.where('failed_at IS NULL AND locked_by IS NOT NULL')

# Queued
Delayed::Job.where('failed_at IS NULL AND locked_by IS NULL')

# Destroy

sauloperez

Have you seen Matthew Inman's (The Oatmeal) comic about why he runs? It's
a classic. In it he talks about his inspiration for taking up long-distance
running. He imagines his tendency to slack off and sit on the couch as a little
creature he calls "The Blerch". It follows him around, tempting him to stop
moving and scarf down junk food.

I run too, though nothing close to the distances Inman runs. In my experience,
refactoring as a skill has a lot in common with running or any other athletic
sport. You can exercise your refactoring muscles, by deliberately working
through the steps with discipline, like we talked about in the last email. As