// Sorts Both the file , individually
// irrespective of their size.
public static void initialize(
String table1, String table1_join_col, String table2, String table2_join_col) {
// System.out.println(DBSystem.PATH_FOR_DATA);
// System.out.println(table1);
tab1 = table1;
tab2 = table2;
for (Table t : DBSystem.tableList) {
if (t.getName().equalsIgnoreCase(table1)) {
table1JoinColIndex = t.getColumnNum().get(table1_join_col);
table1JoinColType = t.getColumnData().get(table1_join_col);
table1Lines = t.getLines();
t1 = t;
} else if (t.getName().equalsIgnoreCase(table2)) {
table2JoinColIndex = t.getColumnNum().get(table2_join_col);
table2JoinColType = t.getColumnData().get(table2_join_col);
table2Lines = t.getLines();
t2 = t;
}
}
// System.out.println(table1 + " - " + table1_join_col + " - " + table1JoinColIndex + " - " +
// table1JoinColType);
// System.out.println(table2 + " - " + table2_join_col + " - " + table2JoinColIndex + " - " +
// table2JoinColType);
if (!table1JoinColType.equalsIgnoreCase(table2JoinColType)) {
System.out.println("Both the tables must have similar join types");
System.exit(1);
}
int numberOfcolumnsForJoin = 2; // For Joining Two tables
// Sort the columns used for join
for (int k = 0; k < numberOfcolumnsForJoin; k++) {
String tab = null;
String tabColType = null;
int tabColIndex = 0;
int tLines = 0;
if (k == 0) {
// Sorting table 1.
tab = table1;
tabColType = table1JoinColType;
tabColIndex = table1JoinColIndex;
tLines = table1Lines;
} else if (k == 1) {
// Sorting table 2
tab = table2;
tabColType = table2JoinColType;
tabColIndex = table2JoinColIndex;
tLines = table2Lines;
}
Comparator<String> cmp = new SortingComparator(tabColIndex, tabColType);
PriorityQueue<String> priorityQueue = new PriorityQueue<String>(10, cmp);
int remainingBufferSize = MAX_MEM_TO_USE;
int fileCount = 1;
String line;
int inOutFlag = 0;
for (int i = 0; i < tLines; i++) {
line = DBSystem.getRecord(tab, i);
// System.out.println(line);
// String cols [] = line.split(",");
remainingBufferSize -= line.getBytes().length;
if (remainingBufferSize >= 0) {
priorityQueue.add(line);
inOutFlag = 1;
} else {
// write to file
FileWriter fileWriter = null;
// System.out.println("Written");
try {
// String fileName = setBlockFile(fileCount,table1);
// System.out.println(fileName);
fileWriter = new FileWriter(new File(setBlockFile(fileCount, tab)));
int siz = priorityQueue.size();
// System.out.println(siz);
for (int j = 0; j < siz; j++) {
fileWriter.write(priorityQueue.poll().toString());
// System.out.println(priorityQueue.poll().toString());
fileWriter.write("\n");
}
fileCount++;
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
fileWriter.close();
} catch (IOException e) {
e.printStackTrace();
}
}
// set remainingSize back to MAX_MEM_TO_USE
remainingBufferSize = MAX_MEM_TO_USE;
// current read line
priorityQueue.add(line);
remainingBufferSize -= line.getBytes().length;
inOutFlag = 0;
}
}
if (inOutFlag == 1) {
FileWriter fw = null;
try {
fw = new FileWriter(new File(setBlockFile(fileCount, tab)));
int psiz = priorityQueue.size();
for (int j = 0; j < psiz; j++) {
fw.write(priorityQueue.poll().toString());
// System.out.println(priorityQueue.poll().toString());
fw.write("\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
if (k == 0) table1_tempfileCount = fileCount;
if (k == 1) table2_tempfileCount = fileCount;
}
// Begin the merging process for both the files.
// System.out.println(table1_tempfileCount);
// System.out.println(table2_tempfileCount);
// Merging Process
SortedMergeJoin sortedMergeJoin =
new SortedMergeJoin(
table1,
table1_tempfileCount,
table1JoinColIndex,
table1JoinColType,
table2,
table2_tempfileCount,
table2JoinColIndex,
table2JoinColType);
sortedMergeJoin.execute();
}
