[FEAT] Indexes and migrations

install/MIGRATION.md

+# Migration from Gargantext < 3.0.0 versions towards >= 3.*
+
+## Installation
+
+First, install Python 3.5 (see https://www.python.org/downloads/ for
+download links).
+
+```bash
+cd /tmp
+wget https://www.python.org/ftp/python/3.5.1/Python-3.5.1.tar.xz
+tar xvfJ Python-3.5.1.tar.xz
+cd Python-3.5.1
+./configure
+make -j4 # option is for multithreading
+sudo make install
+```
+
+Other components are required:
+
+```bash
+sudo pip3.5 install virtualenv
+sudo apt-get install rabbitmq-server
+```
+
+Then build a virtual environment:
+
+```bash
+virtualenv-3.5 VENV
+source VENV/bin/activate
+pip3.5 install git+https://github.com/zzzeek/sqlalchemy.git@rel_1_1
+pip3.5 install -U -r requirements.txt
+```
+
+
+## Migrate database
+
+### Django models
+
+```bash
+./manage.py makemigrations
+./manage.py migrate --fake-initial
+```
+
+...or if it fails, try the commandes below:
+
+```bash
+./manage.py makemigrations
+./manage.py migrate --run-syncdb
+```
+
+(see [Django documentation](https://docs.djangoproject.com/en/1.9/topics/migrations/))
+
+### SQLAlchemy models
+
+```bash
+./dbmigrate.py
+```
+
+
+## Start the Django server
+
+```bash
+./manage.py celeryd --loglevel=INFO # to ensure Celery is properly started
+./manage.py runserver
+```

install/postgres/indexes.sql

+--                       ____ 
+--                      / ___|
+--                     | |  _ 
+--                     | |_| |
+--                      \____|arganTexT
+----------------------------------------------------------------------
+--                  Gargantext optimization of Database             --
+----------------------------------------------------------------------
+
+--> Manual optimization with indexes according to usages
+-- Weakness and Strengths of indexes:
+    --> it can slow down the insertion(s)
+    --> it can speed up  the selection(s)
+
+--> Conventions for this document:
+    --> indexes commented already have been created 
+    --> indexes not commented have not been created yet
+
+----------------------------------------------------------------------
+-- Retrieve Nodes
+----------------------------------------------------------------------
+-- create INDEX on nodes (user_id, typename, parent_id) ;
+-- create INDEX on nodes_hyperdata (node_id, key);
+-- create INDEX on ngrams (id, n) ;
+-- create INDEX on nodes_ngrams (node_id, ngram_id) ;
+-- create INDEX on nodes_ngrams_ngrams (node_id, ngram1_id, ngram2_id) ;
+
+----------------------------------------------------------------------
+-- DELETE optimization of Nodes
+create INDEX on nodes_nodes_ngrams (node1_id);
+create INDEX on nodes_nodes_ngrams (node2_id);
+
+-- Maybe needed soon:
+-- create INDEX on nodes_nodes_ngrams (node1_id, node2_id);
+----------------------------------------------------------------------
+----------------------------------------------------------------------
+----------------------------------------------------------------------
+----------------------------------------------------------------------