Bookkeeping and Tag Database Define a strategy Program
Bookkeeping and Tag Database Define a strategy Program of Work Meeting, June 28 -19, 2000 P. Mato, CERN 28 June 2000 P. Mato, CERN 1
Data structures above Event Data u Entities identified – – u u Data. Set collection of events Run a sub-type of Data. Set MCRun a sub-type of Data. Set Tag. Collection a collection of event tags with a link to the event. An event can only be in one Data. Set An event can be associated to many Tag. Collections 28 June 2000 P. Mato, CERN Tag. Collection * * Event * Data. Set Run MCRun * Run. Param Prod. Param 2
Connection to GAUDI u The Event. Selector is in charge of performing the selection based on a given criteria – Today: Filename, Tape number, Job. Id, First event, Number of events, etc. – Tomorrow: Complex queries to tag and dataset databases u u The Event. Selector returns a pointer (iterator) to the Event header. This pointer is used to get the various event objects by the Persistency. Svc 28 June 2000 P. Mato, CERN selection criteria Event Selector event iterator Data. Sets Tag. Collections 3
Tag. Collection u The idea is to create specialized (LHCb general or private) collections of event tags with a pointer to the event head location Tag Collection data. Set tr. Type vis. E mu. Cand e. Cand XID Event data. Set Event few 100’s bytes 28 June 2000 data. Set P. Mato, CERN 4
Current Status Not existing Tag. Collection * * Event * Data. Set Current Bookkeeping Database Sicb Files (tapes) Run MCRun * Run. Param 28 June 2000 P. Mato, CERN Prod. Param 5
Possibility A u Very attractive – single technology – full navigability – integrity and consistency u u Advocated by RD 45 (CMS) Not very successful with Objectivity Single database for everything (Objectivity? , Oracle? ) Tag. Collection * * Event – Several federations – import/export databases – database catalog management * Data. Set Run * Run. Param 28 June 2000 MCRun P. Mato, CERN Prod. Param 6
Possibility B u Hybrid system – Various technologies – Expertise required u * * Advocated by ROOT – (excluding Tag. Collection) u u DB with Tag. Collections and Data. Sets Tag. Collection Very powerful queries to the event tags are possible Fits well with the GAUDI architecture Event * Data. Set Run Event Data Files * Run. Param 28 June 2000 P. Mato, CERN MCRun Prod. Param 7
Proposal u u Strategy: Study A and B Develop Tag. Collection – Using standard N-tuples (PAW or ROOT based) – Using a relational Database (Oracle based) u u Extent current Event. Selector to include sophisticated queries to Tag. Collections Performance comparisons between A and B 28 June 2000 P. Mato, CERN 8
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