$Id: README,v 1.3 1998/11/12 11:15:42 morita Exp $
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     Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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                           Example E02
                           -----------

This program demonstrates how user can use object database using 
HepODBMS interface.  Please contact your local system manager for
the avaiability of HepODBMS and Objectivity/DB.

To use HepODBMS and underlying Objectivity/DB package, user needs
a deep knowledge of the object database and environmental set
procedures, which is lacking in this release.  The code is provided
here to give just a brief idea of the persistency in using Geant4.

How to build:

- Setup:

In addition to Geant4 standard setup, HepODBMS, Objectivity/DB and
federated database variables should be defined.

For CERN AFS users, an example setup script "g4odbms_setup.csh" is
provided in this directory.  Put a line such as

source ${G4INSTALL}/tests/exampleE02/g4odbms_setup.csh

in your .cshrc file, where ${G4INSTALL} is the actual location of
the Geant4 package.

- Objectivity/DB boot file and lock server

Boot file contains a database schema information of some basic
HepODBMS and Objectivity/DB classes.  Each time you compile your
own persistent-capable class, a schema is compiled into your 
local copy of boot file.  User must compile the Geant4 persistent
capable schema into your local copy of the boot file.
Default location is $HOME/G4EXAMPLE.  If you want to have it
to other location, define the following variables in your .cshrc.

example: 
  setenv G4EXAMPLE_BOOT_DIR   ${HOME}/tmp/G4EXAMPLE
  setenv G4EXAMPLE_BOOT       ${G4EXAMPLE_BOOT_DIR}/G4EXAMPLE

For each boot file, user must have unique federated database ID (FDID).
This number can be obtained from your local manager of Objectivity
lock server.  Define G4EXAMPLE_FDID in your .cshrc.

example:
  setenv G4EXAMPLE_FDID 501

The system also have Objectivity/DB lock server running.  For the
CERN AFS users, see the notes below, for other systems, contact your
local system manager for the lock server configuration.

Then type,

  gmake cleandb

to create your own boot file.
___________________________________________________________________________
Note: On CERN AFS, user must run his/her own lock server process
      due to a technical limitation on AFS and Objectivity.

         oocheckls -notitle `hostname` || \
           oolockserver -notitle -noauto `hostname`::${G4EXAMPLE_BOOT}

      Then check the process with

         ps -ef | grep ools
         ....
         <user>  60156      1   0 06:36:40 pts/15  0:00 ools -OO_NO_AUTOREC
         ....

      When you finish running this example, don't forget to kill
      the lock server process by yourself.

         ookillls
      or
         kill -9 <pid_of_ools>

      User must have AFS ACL access enabled to HepODBMS and 
      Objectivity/DB directories.
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- libG4persistency.a

Persistency in Geant4 is provided as a separate sub category.
Geant4 installer must explictly go to ${G4INSTALL}/source/persistency
directory and type

  cd ...where Geant4 is installed...
  cd source/persistency
  gmake cleandb
  gmake 
  gmake global

to create libG4persistency.a.  This process will also produce a base
schema file in the directory $(G4INSTALL)/schema/.

- exampleE02 executable

exampleE02 executable can be made by simply typing "gmake" in this directory.

Current example of Geant4 persistency requires the executable to be
run as the same directory as your local federated database.
Use exampleE02run csh-script for simple test.

example:
   gmake cleandb    # see above
   gmake            # creates exampleE02 executable
   exampleE02run        # run exampleE02

- Persistent output

When exampleE02 is run correctly, following database files will be created
in your federated database directory.

Events.G4EXAMPLE.DB    G4EXAMPLE.FDDB         System.G4EXAMPLE.DB
G4EXAMPLE              Geometry.G4EXAMPLE.DB

To browse the contents, use "ootoolmgr".

  cd ...your federated database directory...
  setenv DISPLAY <your_x_terminal>:0.0
  ootoolmgr -notitle G4EXAMPLE &

Make sure to terminate ootoolmgr when you finish browsing.
Otherwise lockserver will remember the browsing as a transaction,
and the further updates to the database will be blocked.

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