jamalahmedmaaz

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

• Stores data elements based on an sequential, most commonly 0 based, index.
• Based on tuples from set theory.

jamalahmedmaaz

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

jamalahmedmaaz

General Tip

"The trick is to catch exceptions at the proper layer, where your program can either meaningfully recover from the exception and continue without causing further errors, or provide the user with specific information, including instructions on how to recover from the error. When it is not practical for a method to do either of these, simply let the exception go so it can be caught later on and handled at the appropriate level."

Resources

Advantages of Exceptions
Excellent example of separating error-handling code from program logic

Three Rules for Effective Exception Handling
Longer explanation and case study of exception use, including the basic principles of "throw early" and "catch late". Clear and thorough.

jamalahmedmaaz

// underscore addon with sum, mean, median and nrange function
// see details below

_.mixin({
  
  // Return sum of the elements
  sum : function(obj, iterator, context) {
    if (!iterator && _.isEmpty(obj)) return 0;
    var result = 0;
    if (!iterator && _.isArray(obj)){

jamalahmedmaaz

##################### ElasticSearch Configuration Example #####################

# This file contains an overview of various configuration settings,
# targeted at operations staff. Application developers should
# consult the guide at <http://elasticsearch.org/guide>.
#
# The installation procedure is covered at
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/setup.html>.
#
# ElasticSearch comes with reasonable defaults for most settings,

jamalahmedmaaz

// create an index with an analyzer "myindex"
curl -X PUT localhost:9200/myindex -d '
{
  "settings" : {`
    "index":{
      "number_of_replicas":0,
      "number_of_shards":1,
      "analysis":{
        "analyzer":{
          "first":{

jamalahmedmaaz

package com.fullcontact.hadoop.cassandra;

import com.google.common.collect.Lists;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.db.marshal.CompositeType;
import org.apache.cassandra.db.marshal.UTF8Type;
import org.apache.cassandra.thrift.Column;
import org.apache.cassandra.thrift.ColumnOrSuperColumn;
import org.apache.cassandra.thrift.Mutation;
import org.apache.cassandra.utils.ByteBufferUtil;

jamalahmedmaaz

#!/bin/sh

# one way
# sudo apt-get install scala

#2nd way
sudo apt-get remove scala-library scala
wget www.scala-lang.org/files/archive/scala-2.10.3.deb
sudo dpkg -i scala-2.10.3.deb
sudo apt-get update