* From Benjamin S. Bloom Taxonomy of educational objectives.

Sample etl.xml file :

<etl>
  <connection id="in" driver="csv" url="data.csv">
  headers=false
  </connection>
  <connection id="out" driver="oracle" url="jdbc:oracle:thin:@127.0.0.1:1521:orcl"
      classpath="ojdbc14.jar" user="test" password="test"/>
  <!-- Empty the destination table -->
  <script connection-id="out">
    truncate table TEMP1 ;
  </script>
 
  <query connection-id="in">
      <!-- Empty query means select all columns -->
   <script connection-id="out">
          INSERT INTO TEMP1 VALUES ('$1', $2)
      </script>
  </query>
</etl>

in data.csv :

text1,1
text2,2
text3,3

Sample Java class (ojdbc14.jar and scriptella.jar should be in your class path) :

import scriptella.execution.EtlExecutor;
import scriptella.execution.EtlExecutorException;
 
public class MainRunner {
    public static void main(String[] args) {
 
    try {
         EtlExecutor.newExecutor(new File("etl.xml")).execute();
         } catch (EtlExecutorException e) {
          e.printStackTrace();
           } 
    }
}

Our eyes sometimes seem to play tricks on us in the form of visual illusions. One type of illusion involves impossible figures, such as the one in the video above. Impossible figures fool the brain into creating the impression of a whole figure when the figure is viewed from certain perspectives. In particular, our brains work in two general modes of visual processing:

1- Bottom-up processing: The process by which the brain forms perceptions by piecing together bits and pieces of sensory data to form meaningful patterns.

2- Top-down processing: The process by which the brain forms perceptions by recognizing whole patterns without first piecing together their component parts.

Source : Psychology, Concepts and Applications By Jeffrey S. Nevid

Source: “How to Knock Out Knock Offs,” Business Week, March 14, 2005.

who | grep $1
ps -aux | grep $1

The variable $1 here means the first command line argument, from a shell script. The who command first checks if the user is online, then ps will show all the processes currently running under that user's UID.

Oracle's temporary tables are similar to temporary tables in other relational databases with the main exception being that they are 'statically' defined. You create them once per database, not once per stored procedure in the database. They always exist – they will be in the data dictionary as objects, but will always appear empty until your session puts data into them. The fact that they are statically defined allows us to create views that reference temporary tables, to create stored procedures that use static SQL to reference them, and so on.

Temporary tables may be session-based (data survives in the table across commits but not a disconnect/reconnect). They may also be transaction-based (data disappears after a commit).

Here is an example showing the behavior of both.

create global temporary table temp_table_session
 on commit preserve rows
 as
 select * from scott.emp;

The ON COMMIT PRESERVE ROWS clause makes this a session-based temporary table. Rows will stay in this table until my session disconnects or I physically remove them via a DELETE or TRUNCATE. Only my session can see these rows; no other session will ever see 'my' rows even after I COMMIT:

create global temporary table temp_table_transaction
 on commit delete rows
 as
 select * from scott.emp;

The ON COMMIT DELETE ROWS makes this a transaction-based temporary table. When your session commits, the rows disappear. The rows will disappear by simply giving back the temporary extents allocated to our table – there is no overhead involved in the automatic clearing of temporary tables.

The directive PRAGMA AUTONOMOUS_TRANSACTION tells the database that this procedure, when executed, is to be executed as a new autonomous transaction, independently of its parent transaction.

To ilustrate this by an example, let's create one logging table that will be used to log some actions within your package.

create table actions_log
( username varchar2(30),
timestamp date,
notes varchar2(1000)
);

Then your package will have an autonomous transaction procedure ..

create or replace package body my_pkg
as
procedure log( p_notes in varchar2)
as
pragma autonomous_transaction;
begin
insert into actions_log values
( user, sysdate, p_notes );
commit;
end;
...
...
log ('Action 1');
...
...
end;