reata

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class HashJoin implements JoinStrategy {

    @Override
    public List<Integer> join(List<Integer> R, List<Integer> S) {
        List<Integer> output = new ArrayList<>();
        HashMap<Integer, Integer> RHash = new HashMap<>();

reata

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class SortMergeJoin implements JoinStrategy {
    /*
    time complexity: O(mlog(m)) + O(nlog(n)) + O(m+n), m is the size of R and n is the size of S
     */
    @Override
    public List<Integer> join(List<Integer> R, List<Integer> S) {

reata

import java.util.ArrayList;
import java.util.List;

public class NestedLoopJoin implements JoinStrategy {

    /*
    time complexity: O(m*n), m is the size of R and n is the size of S
     */
    @Override
    public List<Integer> join(List<Integer> R, List<Integer> S) {

reata

/*
 SELECT DISTINCT
 */
WITH foo (pk1, pk2) AS
         (SELECT 1, 'a'
          UNION ALL
          SELECT 1, 'b'
          UNION ALL
          SELECT 2, 'a'
          UNION ALL

reata

/*
 LEFT JOIN without filter, all tuples in foo can find a match in bar
 */
WITH foo (id, bar_id) AS
         (
             SELECT 1, 1
             UNION ALL
             SELECT 2, 1
             UNION ALL
             SELECT 3, 2

reata

#!/usr/bin/python3.6

import ast
from unittest import TestCase


def func1(value):
    data = set()
    if isinstance(value, set):
        data |= value

reata

import socket
import time
from multiprocessing import Pool as ProcessPool
from multiprocessing.dummy import Pool as ThreadPool

import pymysql
import psutil


class Timer: