Wikipedia is the first wiki engine built on MediaWiki. Wiki engines enable collaborative writing and organization for teams. Flat-file systems store content in plain files instead of databases
DBMSs store, organize, access and analyze data using SQL. Data is typically modeled in multiple tables with rows and columns. Businesses need structured data storage for optimal analysis
MongoDB's DATE type stores dates as signed 64-bit integers since Unix epoch. Timestamp type (ID 17) is mainly used for internal processes. Dates are stored internally in UTC format
BotFather creates new bot with HTTP API access token. Node.js version 6.9.4 required for Telegram API. Heroku deployment recommended for continuous availability. Basic setup includes Procfile, app.json, package.json and index.js
MongoTemplate provides basic API for MongoDB persistence. MongoRepository offers more flexible Spring Data-centric operations. Configuration can be done via XML or Java using AbstractMongoConfiguration
Use su command to switch between users without logging out. sudo -u flag launches new shell as specified user. SSH username@localhost works as alternative without sudo