Steps to enable query stats in pgHero dashboard

enable-query-stats.rb

## Modify postgresql.conf 

# Find postgresql.conf 

# ---- For mac users ----
cd /usr/local/var/postgres/  
vi postgresql.conf

# ---- For ubuntu users ----
cd /etc/postgresql/<version>/main
vi postgresql.conf

# Search for term 'shared_preload_libraries' & uncomment it
/shared_preload_libraries
# Set value of 'shared_preload_libraries' & add below mentioned code
shared_preload_libraries = 'pg_stat_statements'         # (change requires restart)
pg_stat_statements.track = all
pg_stat_statements.max = 10000
track_activity_query_size = 2048
# Save changes

## Restart postgreSQL

# ---- For mac users ----
brew services restart postgres

# ---- For ubuntu users ----
sudo /etc/init.d/postgresql restart

## Run below method from Rails console 
PgHero.enable_query_stats

# TO verify, run
PgHero.query_stats_enabled?
# It should return 'true'


## Capture Query Stats from postgreSQL periodically

rails generate pghero:query_stats
rake db:migrate
# This adds a table 'pghero_query_stats' in your database

## Schedule below task to run every 5 minutes

rake pghero:capture_query_stats

# If you're using 'whenever' gem, add below line in /config/schedule.rb 
every 5.minutes do
  rake "pghero:capture_query_stats"
end