GDD

GDD

GDD is the global data dictionary,which controls the meta information for the whole distributed database. Then we design the GDD structure just as follows.

public class GDD {
	HashMap<String,Site>siteList;
	HashMap<String,Schema>schemaList;
	HashMap<String,User>userList;
}

public class Site {
	int Id;
	String name;
	String ip;
	int port;
	boolean isLeader;
}

public class Schema {
	String name;
	int id;
	List<Table>tableList;
	List<Privilege>userList;
	//Statics statics;
}
public class Privilege {
	int use;//1,read, 3, write,5create 7,delete;
	int uid;
	String username;
}
public class Table {
	String tablename;
	int id;
	HashMap<String,Column>columns;
	List<Fragment>fragment;
	List<Privilege>userList;
	int isFragment;
	Statics statics;
}

public class Column {
	int id;
	int dataType;
	String columnName;
	int len;
	int index;//0:none; 1:hashindex; 2:btreeindex; 3:others
	boolean isKey;
}
public class Fragment {
	int fragmentType;//0: horizontal;1:vertical
	List<Condition>condition;
	Table subTable
	int siteId;
	Statics statics;
}
public class Condition {
	String columnName;
	int CompareType;//define less,great,equal..
	String value;
	int dataType;//the datatype of value
}
public class Statics {
	String columnName;
	String min;
	String max;
	String mean;
	String mode;
	String median;
	HashMap<String,Integer>staticList;
}
public class User {
	int uid;
	String username;
	HashMap<String,Privilege>tableList;
	HashMap<String,Privilege>schemaList;
}

Interfaces

• List<String> listTables(String db, String tblPrefix)
• List<String> listTables(String db)
• int createSchema(String schemaName)
• int createTable(Table tableHandle)