Postgres Query: Given an index find associated table

select
    t.relname as table_name,
    i.relname as index_name,
    array_to_string(array_agg(a.attname), ', ') as column_names
from
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
where
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and i.relname = 'Index_to_search_for'
group by
    t.relname,
    i.relname
order by
    t.relname,
    i.relname;
 
 
Source:
http://stackoverflow.com/questions/2204058/list-columns-with-indexes-in-postgresql

Finding table sizes in postgres

Finding table sizes in postgres

Taken from: http://wiki.postgresql.org/wiki/Disk_Usage

SELECT nspname || '.' || relname AS "relation",
    pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
  FROM pg_class C
  LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
  WHERE nspname NOT IN ('pg_catalog', 'information_schema')
    AND C.relkind <> 'i'
    AND nspname !~ '^pg_toast'
  ORDER BY pg_total_relation_size(C.oid) DESC
  LIMIT 20;

Django List Installed Tables and Models

Get Database connection
# Django 1.2
from django.db import connections

connection = connections['default']

# Django 1.1.1<=

from django.db import connection

# Get Database tables

tables = connection.introspection.table_names()

# Get Database models

modelclasses = connection.introspection.installed_models(tables)

# Get Django model name and app name
for model in list(modelclasses):
    print model._meta.app_label, model._meta.module_name

# A better way to get Django models
from django.db.models.loading import get_models, get_app
get_app('app_label')  # returns an app class given a label
get_models()  # all models 
get_models(application)  # models belonging to app class

# Get a model from a string
from django.db import models
models.get_model(*"myapp.mymodel".split('.')) # returns model class

# Get all Python modules

import sys
sys.modules

http://www.slideshare.net/ubernostrum/django-in-depth?src=related_normal&rel=3017822