Getting Started

# 10 minuts getting started Runnable examples are under the folder example, clone this project to your desktop, and run it for yourself.

creation.conf is the configure file that tells LunarBase how to initialize a database. Any parameters in the creation example can be changed to meet your requirements. For example, if you need to cache the hottest 1 million records in memory, you shall change the parameter cache_records_in_memory = 20, (1 << 20 = 1 million). Of course, all the runtime tunable parameters can be changed at any time the db running.

#step 1: create a new database

 String creation_conf = "/home/feiben/EclipseWorkspace/LunarBaseTutorial/creation.conf";  
 LunarDB.getInstance().createDB(creation_conf);  
 LunarDB.getInstance().closeDB();  

Where within the creation.conf, it tells us the database is located under root_path=/home/feiben/DBTest/, and the name is RTSeventhDB.

# ----------------#  
# Global settings #  
# --------------- #  

root_path=/home/feiben/DBTest/  

database_name = RTSeventhDB  

So the db root is /home/feiben/DBTest/RTSeventhDB. The DBTaskCenter knowns from where to create the engine instance:

#step 2: create a new table and insert data to it

String db_root = "/home/feiben/DBTest/RTSeventhDB";  
DBTaskCenter tc = new DBTaskCenter(db_root);  
String table = "order";
if(!tc.getActiveDB().hasTable(table))
{
    tc.getActiveDB().createTable(table); 
    tc.getActiveDB().openTable(table);  
}
		
LunarTable l_table = tc.getActiveDB().getTable(table);
l_table.addSearchable("string", "name");
l_table.addSearchable("int", "payment");
l_table.addSearchable("int", "age");
		
			
/*  
 * Step 1: construct an object of a records array  
 */  
 String[] records = new String[6];  
 records[0] = "{name=jackson8, payment=500, age=36}";  
 records[1] = "{name=jackson9, payment=500, age=25}";  
 records[2] = "{name=John8, payment=600, age=36}";  
 records[3] = "{name=Rafael8, payment=600, age=36}";  
 records[4] = "{name=Rafael9, payment=700, age=25}";  
 records[5] = "{name=John9, payment=700, age=36}";  
 		
 /*  
  * Step2: dispatch it. LunarBase engine handles it.  
  */  
 LFuture<Record32KBytes[]> inserted = tc.dispatch(new IncommingRecords(table, records));  
 tc.saveDB();  

#step 3: simple query

 /*  
  * Step 3: Test query, see if they are correctly inserted,   
  * and if property-value pair can be retrieved.   
  */  
 QuerySimple sq = new QuerySimple(table, "age", "36", 200);  
 tc.dispatch(sq);

#step 4: shut down the database

 /*  
  * Step 4: Must not forget to shut down the db.  
  */  
 tc.shutdownDB();