emilong

Undo/Redo

Undo/Redo is one of those features of an application that you almost always need to have if you are building serious GUI tools for people to do work.

The best way to look at undo/redo is two stacks of operations the user has performed:

• The Undo stack is the "history" of what they've done
• The redo stack is the breadcrumbs back to the initial state before they started undoing

emilong

#!/bin/bash

# Log and graph peformance metrics on a single process
# Based on: http://brunogirin.blogspot.com.au/2010/09/memory-usage-graphs-with-ps-and-gnuplot.html
#
# Requires gnuplot to be installed and on your path.
#
# Run: ./process_graph [process name] [pid]

DEFAULT_PROCNAME="Xorg"

emilong

--- PSQL queries which also duplicated from https://github.com/anvk/AwesomePSQLList/blob/master/README.md
--- some of them taken from https://www.slideshare.net/alexeylesovsky/deep-dive-into-postgresql-statistics-54594192

-- I'm not an expert in PSQL. Just a developer who is trying to accumulate useful stat queries which could potentially explain problems in your Postgres DB.

------------
-- Basics --
------------

-- Get indexes of tables

emilong

#!/bin/bash
# Add to instance metadata with `gcloud compute instances add-metadata \
#   instance-name --metadata-from-file startup-script=idle-shutdown.sh` and reboot
# NOTE: requires `bc`, eg, sudo apt-get install bc
# Modified from https://stackoverflow.com/questions/30556920/how-can-i-automatically-kill-idle-gce-instances-based-on-cpu-usage
threshold=0.1

count=0
wait_minutes=60
while true

emilong

-- index usage stats
SELECT 
  relname, 
  100 * idx_scan / (seq_scan + idx_scan) percent_of_times_index_used, 
  n_live_tup rows_in_table
FROM 
  pg_stat_user_tables
WHERE 
    seq_scan + idx_scan > 0 
ORDER BY