This page provides information about the BaBar conditions(CDB) and configuration(CfgDB) based on the ROOT file format. Only the read-only version that is used for analysis and simulation production jobs are dicussed. Most of the topics disussed below apply equally to a CfgDB and CDB snapshots. The main difference between these two is that a CfgDB snapshot consits of a single file whereas a CDB snapshot consists of many files. Therefore, for a CDB snapshot a bootfile (file catalog) is needed which is absent for a CfgDB snapshot.
The figure below shows the steps that are involved to create a snapshot and make it available to users.
A Snapshot is extracted from a production federation and it consists of a set of root files. These files are transfered into HPSS and the kan xrootd-cluster at SLAC. The files (collections) of a snapshot are published in the Bookkeeping and the dataset that corresponds to the snapshot is updated and tagged. In order to make the snapshot available to users Rule files are updated. These rule files are used to map a generic file name (e.g.: cdb_boot.root) to a locigal/physical file name (e.g.: /store/cdb/cond18boot/betamini/2006/08/20060831T105009/CDB-20060831T105009-cdb_boot.root) that can be opened using xrootd for example.
A user has to setup its environment in order to use the root based conditions and configurations.
As usual snapshots can be Imported and used at a local site (Tier-A,-B or Laptop).