Typescript Data Engine

Brief Description: A simplified query engine written with Typescript for a small in memory dataset.

Table of Contents

• Installation:

  • Requirements:
    • NodeJs v20.18.0
    • Npm v10.8.2
  • Instructions:
    • Install dependencies: npm install
    • Build: npm run build
    • Run: npm run start
  • Unit Tests:
    • npm run test
  • Usage:
    • Once the ingest phase has completed, the user can type a query.
    • Typing the command exit the session terminates.
    • Any query can be composed using the following grammar:

      Query = Project Filter | Project | Filter
      
      Number = digit* "." digit+ | digit+
      
      String = "\""alnum+"\""
      
      columnName = ("0".."9"|"a".."z"|"A".."Z"|"-"|"_")+
      
      Columns = ListOf<columnName, ",">
      
      Project = ("PROJECT" | "Project" | "project") Columns
      
      Filter = ("FILTER" | "Filter" | "filter") FilterPredicate
      
      FilterPredicate = columnName "<" String
      | columnName ">" String
      | columnName "=" String
      | columnName "<" Number
      | columnName ">" Number
      | columnName "=" Number
      
      

• Examples:

  • PROJECT operatingSystem, appUsageTime FILTER userID > 500
  • PROJECT deviceModel, batteryDrain, screenOnTime
  • PROJECT userID, operatingSystem, numberOfAppsInstalled
  • FILTER userID > 500
  • FILTER deviceModel = "Google Pixel 5"
  • FILTER deviceModel > "iPhone"

• Modules:

  • Ingest: loads data into memory, convert numeric fields, create primary key and indexes
  • Parser: parse and validate user-defined queries
  • Engine: executes queries
  • Orchestrator: starts up the system and handle the user interaction