CMS Persistent Event Structure Vincenzo Innocente CERN, EP/CMC RD45 4/98 Vincenzo Innocente

Top Level Structure Run Event Event RawEvent RecEvent RecEvent Collection Event Collection Run In case of re-reconstruction the original structure is kept. Event objects are cloned and new collections created (classification may change). Event Event RawEvent RecEvent Event Header RecEvent The Event object could disappear and Event become just a super-class of Raw&RecEvent RD45 4/98 Vincenzo Innocente

Object Model RD45 4/98 Vincenzo Innocente

Object Model RD45 4/98 Vincenzo Innocente

... Raw Event RawEvent ReadOut ReadOut RawData RawData Index RawData are identified by the corresponding ReadOut. RawData belonging to different “detectors” are clustered into different containers. The granularity will be adjusted to optimize I/O performances. An index at RawEvent level is used to avoid the access to all containers in search for a given RawData. A range index at RawData level could be used for fast random access in complex detectors. RawEvent ReadOut ReadOut ... RawData RawData Vector of Digi Vector of Digi Index implemented as an ordered vector of pairs RD45 4/98 Vincenzo Innocente

Reconstructed Objects RecEvent Reconstructed Objects Reconstructed Objects produced by a given “algorithm” are managed by a Reconstructor. S-Track Reconstructor Track SecInfo A Reconstructed Object (Track) is split into several independent persistent objects to allow their clustering according to their access requirements (physics analysis, reconstruction, detailed detector studies, etc.). The top level object acts as a proxy. Intermediate reconstructed objects (Hits) are transient and are cashed by value into the final objects . Track Constituents S Track ... Vector of Hits S Track RD45 4/98 Vincenzo Innocente

Reconstructed Event New Old RecEvent RecEvent S-Jet Reconstructor A direct association to previous RecEvent allows the access to any obsolete Reconstructor S-Track Reconstructor Old RecEvent S-Jet A Reconstructor has references to the Reconstructors used to “build” its RecObjs “Old”, still valid, Reconstructor are associated uni-directionally S-Jet Reconstructor My-Jet RD45 4/98 Vincenzo Innocente

Meta-Data Event RecEvent S-Track GRecParam A RecObj is identified User Configuration Meta-Data A ooGenObj is used to manage RecParam versions S-Track GRecParam General “job” conditions (new each transaction?) Event A RecObj is identified by its Type, a Name and a Version. Vm.m S-Track RecParam RecEvent Vn.n S-Jet RecParam The name (and the version) is always relative to a given context: for instance the Container of RecParams S-Track Reconstructor A Reconstructor is associated to its version of RecParam which is used also to instantiate the correct RecUnit S-Jet Reconstructor S-Jet RecUnit RD45 4/98 Vincenzo Innocente