Recommended DataBase tags


This is based on Thomas Ruf's talk at T-rec on 13/7/09.

Why different tags for MC?

For real data, new tags mean better description of existing detector. For MC data, the best description is the one used during the simulation step. Therefore, why different Tags for MC ?
  • Special settings, Velo open, B field off, ... are identified with a Tag and this Tag needs to be used when reconstructing and analysing the data
  • There can be changes in the software which require changes in the databases. Newer software versions might not work anymore with old Tag of database. Requires some intelligence for defining compatible tags.


DataType, DDDBtag, CondDBtag, Simulation flag. The DaVinci and Brunel configurable has a variable called DataType, which is the main knob for most use cases. The information is forwarded to the LHCbApp configurable. Known DataTypes are:
LHCbApp().DataType = 'MC09' # or 'DC06, '2008', '2009'
If nothing else specified, the LHCbApp will be instrumented to use the default tag:
LHCbApp().DDDBtag = 'default' 
LHCbApp().ConDBtag = 'default' 
The simulation flag is used to switch from LHCbCONDto SIMCOND database for conditions.
LHCbApp().Simulation = 'True' # or 'False'
In some cases, 'DC06', 'MC09', implicitly set by choice of DataType.

Leaving the choice of Tag to the DDDB configurable will solve most use cases. Only needed to specify the DataType corresponding to the data to be used. NOTE: Only one set of tags can be used in one execution. It is not possible to mix data which would require different Tags.

Default tags

The default tag is resolved by DDDB/ Which means, the actual Tag used depends on the version of LHCb. The person changing DDDB/ has to make sure that a new Tag is compatible with the DataType. For example LHCB v27r3:
  • 'DC06': “DC06-20081002“ for DDDB and LHCBCOND Note: SIMCOND does not exist for DC06, Simulation flag set to False, bfield polarity = -1 forced
  • '2008': “head-20090330” for DDDB, “head-20090402” for LHCBCOND and “sim-20090212” for SIMCOND
  • 'MC09': “MC09-20090602” for DDDB and “sim-20090402-vc-md100” for SIMCOND, Simulation flag ignored
  • '2009': “head-20090617” for DDDB, “head-20090508” for LHCBCOND and “sim-20090508-vc-md100” for SIMCOND. Simulation flag for switching between SIMCOND and LHCBCOND

Where do I find information about used tags:

  • Start of job, tells what will be used:
    • # WARNING: Default tag requested for partition DDDB (using DC06-20081002)
    • # WARNING: Default tag requested for partition LHCBCOND (using DC06-20081002)
  • In each event, Rec/Header for example contains information which Tag had been used during reconstruction
>>> evt['Rec/Header']
      • { randomSeeds : [340212, 5501, 540002744, 0] ...
      • condDBTags : [(DDDB, head-20081002), (SIMCOND, head-20081002)]
  • Bookkeeping using dirac tools (SetupProject Dirac, lhcb-proxy-init):
    • dirac-bookkeeping-production-informations 4918
      • Step0:Gauss-v37r2 Option files: $APPCONFIGOPTS/Gauss/;$APPCONFIGOPTS/Conditions/;$DECFILESROOT/options/30000000.opts;$LBPYTHIAROOT/options/Pythia.opts *DDDb: MC09-20090602 ConDDb: sim-20090402-vc-md100 *; ...
      • Step2:Brunel-v34r7 Option files: $APPCONFIGOPTS/Brunel/; $APPCONFIGOPTS/Conditions/ * DDDb: MC09-20090602, ConDDb: sim-20090402-vc-md100*

Where do I find information about global tags

  • LHCb->Computing->DDDB
  • Example 1 "DC06-20081002":
    • DDDB: based on "DC06-20080930"
    • LHCBCOND: based on "DC06-20080930" plus: calo-DC06-20081002 …
      • Global tag "DC06-20080930": DDDB: based on "DC06-20080904" plus: calo-20080923, calo-20080905
        • 2008-09-23 - Olivier Deschamps
        • DDDB: calo-20080923 (show files)
        • LHCBCOND: calo-20080923 (show files)
        • SIMCOND: calo-20080923 (show files)
        • Reorganized conditions with some new ones.
  • Example 2 "MC09-20090602":
    • DDDB: based on "MC09-20090526" plus: ot-20090519
      • DDDB: ot-20090519 Fixed wrong material for the Roha component of a coupling.
        • Global tag "MC09-20090526": DDDB: based on "MC09-20090519" plus: velo-20090526, particles-20090526

-- ThomasRuf - 14 Jul 2009

This topic: LHCb > WebHome > LHCbComputing > RecommendedTags
Topic revision: r3 - 2009-07-14 - unknown
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