JDBM纯Java数据库性能测试评估
JDBM性能测试评估，最近想选择一个轻量、可伸缩、高性能的嵌入式数据库，所以对JDBM 纯Java数据库进行了测试评估。从结果看来JDBM还是挺不错的，和db4o,Perst,Berkeley DB是一个级别的，每秒能插入10000个对象，10000次对象查询能在1秒内完成，删除10000个对象也大约能在1-2秒内完成。看来表现最差的JISP，insert、search、delete差不多都需要30秒。
版本：
jdbm-unspecified.jar（1.0）
结果：
Elapsed time for inserting 100000 records: 12282 milliseconds
Elapsed time for performing 100000 index searches: 7125 milliseconds
Elapsed time for deleting 100000 records: 16203 milliseconds
代码：
import java.util.Properties;import jdbm.RecordManager;
import jdbm.RecordManagerFactory;
import jdbm.helper.StringComparator;
import jdbm.btree.BTree;
public class FamousPeople {static String DATABASE = "people";
static String BTREE_NAME = "FamousPeople";/**
* Example main entrypoint.
*/
public static void main( String[] args ) {
RecordManager recman;
long recid;BTree tree;
Properties props;props = new Properties();
try {
// open database and setup an object cache
recman = RecordManagerFactory.createRecordManager( DATABASE, props );// try to reload an existing B+Tree
recid = recman.getNamedObject( BTREE_NAME );
if ( recid != 0 ) {
tree = BTree.load( recman, recid );
System.out.println( "Reloaded existing BTree with " + tree.size()
+ " famous people." );
} else {
// create a new B+Tree data structure and use a StringComparator
// to order the records based on people's name.
tree = BTree.createInstance( recman, new StringComparator() );
recman.setNamedObject( BTREE_NAME, tree.getRecid() );
System.out.println( "Created a new empty BTree" );
}// insert people with their respective occupation
System.out.println();
long key = 1999;
int nRecords=100000;
long start=System.currentTimeMillis();
for (int i = 0; i < nRecords; i++) {
key = (3141592621L*key + 2718281829L) % 1000000007L;
tree.insert( key+"", Long.toString(key), false );
}
System.out.println("Elapsed time for inserting " + nRecords + " records: "
+ (System.currentTimeMillis() - start) + " milliseconds");
key = 1999;
start=System.currentTimeMillis();
for (int i = 0; i < nRecords; i++) {
key = (3141592621L*key + 2718281829L) % 1000000007L;
tree.find( key+"" );
}
System.out.println("Elapsed time for performing " + nRecords + " index searches: "
+ (System.currentTimeMillis() - start) + " milliseconds");
key = 1999;
start=System.currentTimeMillis();
for (int i = 0; i < nRecords; i++) {
key = (3141592621L*key + 2718281829L) % 1000000007L;
tree.remove( key+"" );
}
System.out.println("Elapsed time for deleting " + nRecords + " records: "
+ (System.currentTimeMillis() - start) + " milliseconds");// make the data persistent in the database
recman.commit();recman.close();
} catch ( Exception except ) {
except.printStackTrace();
}
}
}