Calling a java loaded API from PL/SQL

Question

HI,
I have a java program loaded in the Database.
For sake of clarity I am posting the java Program also.
package mypackage1;
public class WriteClob extends CLOB
public static void main(String[] args) {
Connection conn = null;
String url = null;
String user = null;
String password = null;
Properties props = new Properties();
String fileName = null;
String xml_test ="KINGSTON";
StringBuffer s_xml = new StringBuffer();
// PreparedStatement ps = null;
OraclePreparedStatement ps=null;
int ret_int=0;
props.put("user", "apps" );
props.put("password", "apps");
long len=0;
int temp;
ResultSet rs = null;
SimpleDateFormat fSDateFormat = null;
props.put("SetBigStringTryClob", "true");
long first=System.currentTimeMillis();
url = "jdbc:oracle:thin:@ap619sdb:4115:owf12dev";
user = "apps";
password = "apps";
try
DriverManager.registerDriver(new OracleDriver()); // Get the database connection
conn = DriverManager.getConnection( url, props );
long second=System.currentTimeMillis();
System.out.println("Time between conn. "+(second-first));
first=System.currentTimeMillis();
for (int i =0;i<1000;i++){
s_xml.append(xml_test);
second=System.currentTimeMillis();
System.out.println("Time between loop "+(second-first));
first=System.currentTimeMillis();
ps =(OraclePreparedStatement) conn.prepareStatement("insert into xml_clob_temp1 values(:1)");
ps.setString(1,s_xml.toString());
ps.executeUpdate();
second=System.currentTimeMillis();
System.out.println("Time between loop "+(second-first));
} catch(SQLException sqlexp){ sqlexp.printStackTrace(); }
Now i am trying to create a procedure to call this Java API.
create or replace package load_perf as
procedure WriteClob ;
end;
create or replace package body load_perf as
procedure WriteClob
is
language java name 'mypackage1.WriteClob.main(java.lang.String)';
end;
I have tried debugging this a lot and am not able to overcome this error while creating the procedure.
LINE/COL ERROR
3/1 PL/SQL: Item ignored
5/15 PLS-00311: the declaration of
"mypackage1.WriteClob.main(java.lang.String)" is incomplete or
malformed
I have earlier created Java APIs which have returned some value and have been able to load them in the DB and call through a PL/SQL function wrapper.
But I am unable to create a procedure for this.
I have tried all sorts of debugging but always am getting error around this.
Can someone Please take a look at this Pronblem.
Thanks In Advance,
Gaurav

Answer 1

A proper designed application in the database tier is far more scalable and performs better than using a separate middle tier for the application.
This should be self evident.
A middle tier requires more moving parts between the application and data. There now sits a network pipe between application and data. There are more software layers that slows down the interaction of the application with the data - more stuff that can go wrong. More stuff that needs to be maintained and configured and secured.
What's more, the database tier is a lot more scalable than the middle tier. Oracle Real Application Clusters. Oracle Parallel Processing. Oracle Shared Server. Etc.
These are robust and mature technologies.
One major fact that seems to be missed by so-called IS architects favouring a middle tier is that the middle tier cannot make a single database query or transaction go faster.
Scaling the middle tier is done by throwing more hardware at it. But not a single additional mid-tier h/w platform will make the database tier any faster. Will make the database tier scale.
Then there is also the issue of costs. A middle tier requires additional hardware. It requires support and maintenance agreements with the vendors. It requires middle tier software to be purchased. It requires a new set of skills to do middle tier development. It deals with different technology and different programming languages.
Why? How can this approach be sensible when:
- Oracle scales exceedingly well (and this scalability is not dependent on more h/w purchasing)
- Oracle deals with a single programming language (PL/SQL)
- Oracle supports high availability
- Oracle supports redudancy
- Oracle supports the complete application tier inside the database
If you have problems now leveraging Oracle (as an application tier), then you will have more problems when doing it a middle layer. Why?
Because the lack of experience/skill/knowledge required to make Oracle work for you, is not now suddenly negated and not needed when moving the application tier to Java.