add to output number of rows retrieved

Author: guyplusplus

README.md

@@ -6,6 +6,8 @@ It was developed to compare MySQL replicas, in particular for a MySQL InnoDB clu
 
 ## Algorithm
 
+The tool first retrieves schema information and ensures that tables can be compared. Two tables can be compared when they carry the same columns and the same primary keys. The tool issues warning when columns or primary keys are different type or different ordinal position.
+
 The tool compares md5 of the row, simply speaking `select concat(pk1, pk2) PK, md5(concat(pk1, pk2, coalesce(c1, 'null'), coalesce(c2, 'null'), ...)) MD5 from mytable order by pk1, pk2`. If some primary keys are missing on either master or slave database, or md5 value is not matching, the tool reports the difference, showing the primary keys.
 
 The tool being optimized for tables very similar in content, it retrieves 1 row alternatively from master then slave table. As data is sorted by PK, it keeps a sorted list of differences (pk and md5 value) in memory. As soon as there is a match, any value lower than the match pair is immediately reported and removed from memory. Memory footprint shall then remain small.
@@ -26,6 +28,7 @@ Here is a sample output from the test cases.
 
 ```
 Loading Database Schema Metadata MASTER
+
 Loading Database Schema Metadata Slave #1
 Comparing Database Schema Metadata MASTER with Slave #1
     ERROR object:onlyina, differenceType:TABLE_MISSING_IN_SLAVE_SCHEMA
@@ -68,6 +71,8 @@ In scope tables: tab1 tab2 tab3 tab5
     ERROR object:tab3, differenceType:DATA_ROW_MISSING_IN_SLAVE_TABLE, note:(uid,sometext2)=(4,d2)
     ERROR object:tab3, differenceType:DATA_ROW_EXCESS_IN_SLAVE_TABLE, note:(uid,sometext2)=(4,d3)
     ERROR object:tab3, differenceType:DATA_ROW_EXCESS_IN_SLAVE_TABLE, note:(uid,sometext2)=(6,e2)
-Comparing Database Schema MASTER with Slave #1 - Complete. Duration(ms): 56
+Comparing Database Schema MASTER with Slave #1 complete
+Duration(ms): 53. Total rows retrieved from master: 19, slave: 20
+
 Job Done. Count Summary warningCount:14, errorCount:24
 ```

src/main/java/com/geckotechnology/mySqlDataCompare/App.java

@@ -38,8 +38,10 @@ public static void main(String[] args)
 		for(int i = 1; i<args.length; i++) {
 			MySQLSchemaRetriever slaveSchemaReader = null;
 			Schema slaveSchema = null;
+			MySQLTableDataComparer tableDataComparer = null;
 			long startTime = System.currentTimeMillis();
 			try {
+				System.out.println();
 				System.out.println("Loading Database Schema Metadata Slave #" + i);
 				slaveSchemaReader = new MySQLSchemaRetriever(args[i]);
 				slaveSchemaReader.openConnection();
@@ -61,7 +63,7 @@ public static void main(String[] args)
 				}
 				System.out.println();
 				//start comparison
-				MySQLTableDataComparer tableDataComparer = new MySQLTableDataComparer(masterSchemaReader, slaveSchemaReader);
+				tableDataComparer = new MySQLTableDataComparer(masterSchemaReader, slaveSchemaReader);
 				for(Table table:tablesReadyToBeDataAnalyzed)
 					tableDataComparer.compareTable(table);
 				tableDataComparer.printDataDifferenceDetails();
@@ -77,7 +79,12 @@ public static void main(String[] args)
 				if(slaveSchemaReader != null)
 					slaveSchemaReader.closeConnection();	
 				long endTime = System.currentTimeMillis();
-				System.out.println("Comparing Database Schema MASTER with Slave #" + i + " - Complete. Duration(ms): " + (endTime - startTime));
+				System.out.println("Comparing Database Schema MASTER with Slave #" + i + " complete");
+				System.out.print("Duration(ms): " + (endTime - startTime));
+				if(tableDataComparer != null)
+					System.out.print(". Total rows retrieved from master: " + tableDataComparer.getMasterTotalRetrievedRows() +
+							", slave: " + tableDataComparer.getSlaveTotalRetrievedRows());
+				System.out.println();
 			}
 		}
 
@@ -89,6 +96,7 @@ public static void main(String[] args)
 
 		}
 
+		System.out.println();
 		System.out.println("Job Done. Count Summary warningCount:" + warningCount + ", errorCount:" + errorCount);
 		if(errorCount>0)
 			System.exit(1);

src/main/java/com/geckotechnology/mySqlDataCompare/MySQLTableDataComparer.java

@@ -12,12 +12,22 @@ public class MySQLTableDataComparer {
 	private ArrayList<SchemaDifference> dataDifferences = new ArrayList<SchemaDifference>();
 	private MySQLSchemaRetriever masterSchemaReader;
 	private MySQLSchemaRetriever slaveSchemaReader;
+	private int masterTotalRetrievedRows;
+	private int slaveTotalRetrievedRows;
 
 	public MySQLTableDataComparer(MySQLSchemaRetriever masterSchemaReader, MySQLSchemaRetriever slaveSchemaReader) {
 		this.masterSchemaReader = masterSchemaReader;
 		this.slaveSchemaReader = slaveSchemaReader;
 	}
 
+	public int getMasterTotalRetrievedRows() {
+		return masterTotalRetrievedRows;
+	}
+
+	public int getSlaveTotalRetrievedRows() {
+		return slaveTotalRetrievedRows;
+	}
+
 	public void compareTable(Table table) throws Exception {
 		//note that only 1 SQL statement is used for both tables, even if column or PK columns are not in the same order
 		StringBuilder selectSQL = table.createSQLToGetAllRows();
@@ -35,6 +45,7 @@ public void compareTable(Table table) throws Exception {
 			//Get 1 row from master DB
 			if(hasMasterResultSetNext && masterResultSet.next()) {
 				OneRow masterOneRow = new OneRow(masterResultSet.getString(1), masterResultSet.getString(2));
+				masterTotalRetrievedRows++;
 				int slaveRowIndex = slaveRows.indexOf(masterOneRow);
 				if(slaveRowIndex != -1) {
 					//slave row matching PK has been found
@@ -69,6 +80,7 @@ public void compareTable(Table table) throws Exception {
 			//Get 1 row from slave DB
 			if(hasSlaveResultSetNext && slaveResultSet.next()) {
 				OneRow slaveOneRow = new OneRow(slaveResultSet.getString(1), slaveResultSet.getString(2));
+				slaveTotalRetrievedRows++;
 				int masterRowIndex = masterRows.indexOf(slaveOneRow);
 				if(masterRowIndex != -1) {
 					//slave row matching PK has been found