diff --git a/DBEngine.cpp b/DBEngine.cpp
index 9bfc700..b0eb5d2 100755
--- a/DBEngine.cpp
+++ b/DBEngine.cpp
@@ -52,15 +52,46 @@ void DBEngine::save(){
 	file.close();
 }
 
+void DBEngine::deleteRelation(string n)
+{
+	// to conserve memory after closing a file.
+	for(int i = 0; i < tables.size(); i++)
+	{
+		if (tables[i].getTableName() == n)
+		{
+			 tables.erase(tables.begin() + i);
+		}
+	}
+}
+
 void DBEngine::save(string n){
 	
 	ofstream file;
 	string name = n + ".txt";
 	file.open(name);
 	
-	for(int i = 0; i < commands.size(); ++i)
+	for(int i = 0; i < commands.size() - 1; ++i)
 	{
-		file << commands[i] << endl;
+		if(commands[i].substr(0, 4) == "SAVE")
+		{
+			continue;
+		}
+		if(commands[i].substr(0, 4) == "SHOW")
+		{
+			continue;
+		}
+		if(commands[i].substr(0, 4) == "OPEN")
+		{
+			continue;
+		}
+		if(commands[i].substr(0, 5) == "CLOSE")
+		{
+			continue;
+		}
+		else
+		{
+			file << commands[i] << endl;
+		}
 	}
 	
 	//file.close();
diff --git a/DBEngine.h b/DBEngine.h
index d23dffb..de714f6 100755
--- a/DBEngine.h
+++ b/DBEngine.h
@@ -22,7 +22,8 @@ public:
 	void saveToFile(vector<string> cmds);
 	Relation selection(string attName, string s, Relation r);
 	Relation projection(vector<string> input, Relation r);
-	Relation product(string s1, Relation r1, Relation r2);
+	Relation product(string s1, Relation r1, Relation r2);
+	void deleteRelation(string n);
 	void save();
 	void save(string n);
 	void storeCommands(string s);
diff --git a/Parserv4.cpp b/Parserv4.cpp
index 92dcb19..78b39a5 100644
--- a/Parserv4.cpp
+++ b/Parserv4.cpp
@@ -109,9 +109,11 @@ vector<string> closeCMD(vector<string> input, DBEngine &engine)
 		cout<<"Syntax error!"<<endl;
 	}
 	
-	PRelation r(input[0]);
+	//PRelation r(input[0]);
 	
 	// send close command to DBEngine	
+	engine.deleteRelation(input[0]);
+	input.erase(input.begin());
 	
 	return input;
 }
@@ -123,9 +125,18 @@ vector<string> openCMD(vector<string> input, DBEngine &engine)
 		cout<<"Syntax error!"<<endl;
 	}
 	
-	PRelation r(input[0]);
+	//PRelation r(input[0]);
 	
 	// send open command to DBEngine
+	string name = input[0] + ".txt";
+	ifstream file;
+	file.open(name);
+	string line;
+	while(getline(file, line))
+	{
+		parse(line, engine);
+	}
+	file.close();
 	
 	return input;
 }
diff --git a/test b/test
index 8eb7a6d..71512f2 100755
Binary files a/test and b/test differ