OO-2826: add if exists to the drop table

src/main/java/org/olat/course/statistic/PostgreSQLTempStatTableCreator.java

@@ -55,9 +55,9 @@ public class PostgreSQLTempStatTableCreator implements IStatisticUpdater {
 		final long startTime = System.currentTimeMillis();
 		log_.info("updateStatistic: dropping o_stat_temptable if still existing");
 		try {
-			jdbcTemplate.execute("drop table o_stat_temptable;");
+			jdbcTemplate.execute("drop table if exists o_stat_temptable;");
 		} catch (Exception e) {
-			//
+			log_.error("Cannot drop the temporary table", e);
 		}
 		
 		try{

src/main/java/org/olat/course/statistic/StatisticUpdateManagerImpl.java

@@ -151,8 +151,6 @@ class StatisticUpdateManagerImpl implements StatisticUpdateManager, GenericEvent
 					
 					Date lastUpdatedDate = new Date(lastUpdatedInMilliseconds);
 					Date nowDate = new Date(nowInMilliseconds);
-					
-					System.out.println(lastUpdatedDate + " :: " + nowDate);
 
 					log_.info("updateStatistics: starting the update");
 					DBFactory.getInstance().intermediateCommit();