Minutes of the ATLAS/POOL integration meeting, 07/08/2003

1) Current status of the POOL integration into the ATLAS
   software framework.

   Valeri presented the current status of the AthenaPOOL
   package. It is based on POOL_1_1_0 (SEAL_0_3_2, ROOT 3.05.05).
   The whole write/read chain of objects has been achieved.
   There are already examples in the ATLAS CVS repository.

   It has been recommended to set up a process which will enable
   picking up of the latest POOL internal releases, for early
   feedback on bugs and requirements from ATLAS.

2) Underlying versions of SEAL and ROOT now and in the near future.

   Given that ATLAS will use only the Dictionary from SEAL in the
   near future (i.e. no framework services), they will be picking
   up the SEAL and ROOT versions from the POOL release in use.

3) The ultimate set of the POOL libraries used by ATLAS;
   Will the POOL default cache management (DataSvc) be used?

   The question is mainly there to address whether the DataSvc
   cache and Refs will be used.

   For the moment the two caches (POOL-DataSvc, Athena-StoreGate)
   coexist because every object in StoreGate is copied to the
   POOL cache. This requires that every storable class should define
   a copy constructor.

   In the POOL 1.2.0 release there is the possibility to set the
   policy of the POOL cache such that it does not claim ownership
   of the objects.

   At the same time there has been a proposal by POOL to ATLAS to
   look into the possibility of using directly the interfaces one
   level lower (PersistencySvc). This would in anycase require the
   writing of a reference handler for the ATLAS reference objects
   (DataLink). This possibility is currently investigated by Paolo.

   Writing a reference handler for DataLink seems to be something
   that will be anyway required as soon as the ATLAS EventHeader
   class will be optimized for performance.

4) Top priority requirements in terms of missing functionality.

   For the moment existing pending requirements are already
   implemented in the POOL internal releases(eg. vector of bool),
   or they have to address SEAL (enumerations).

   ATLAS will try out the new POOL 1.2.0 release in terms of
   example cases, more intensively as of next week.

5) Production plans for this year and services required.

   Some dates given by David Q. :
   10/09/2003 : Atlas software version 7.0 (pre-production release)
   Fall 2003  : Migrating 40 TB of data from DC1 to POOL.
   xx/02/2004 : Atlas software version 7.0 (ready for DC2)

   The sites (besides CERN) where a RLS service should be available
   include BNL.

6) Assistance, consultancy, additional example and test cases.

   ATLAS has asked POOL to provide an example where a custom
   DataCallBack object is registered for a class, so that the
   transient and the persistent shapes differ.
   This means that not all members of a class are written, and
   some of them are written using a different type.
   The example will be provided hopefully next week after the
   POOL 1.2 release.