Data is produced or processed with different database tags. For example if the VELO was open, the database tag needs to specify that.

Look at your datafiles from the bookkeeping: the file names contain the dataset number. For the following datafile the dataset number is 5630.

DATAFILE='LFN:/lhcb/MC/MC09/DST/00005630/0000/00005630_00000001_1.dst

To look up the tags log in to lxplus (you need a Grid Certificate to do this):

SetupProject LHCbDirac
dirac-bookkeeping-production-informations <datasetNumber>

for example:

dirac-bookkeeping-production-informations 5630

This produces the output:

Production Info: 
    Configuration Name: MC
    Configuration Version: MC09
    Event type: 30000000
Step0:Gauss-v37r5
      Option files: $APPCONFIGOPTS/Gauss/MC09-b450GeV-md100-nu1.py;$APPCONFIGOPTS/Conditions/MC09-20090602-vo-md100.py;$DECFILESROOT/options/30000000.opts;$LBPYTHIAROOT/options/Pythia.opts
      DDDb: MC09-20090602
      ConDDb: sim-20090402-vo-md100
Step1:Boole-v19r7
      Option files: $APPCONFIGOPTS/Boole/MC09-WithTruth.py;$APPCONFIGOPTS/Conditions/MC09-20090602-vo-md100.py
      DDDb: MC09-20090602
      ConDDb: sim-20090402-vo-md100
Step2:Brunel-v35r7
      Option files: $APPCONFIGOPTS/Brunel/MC09-WithTruth.py;$APPCONFIGOPTS/Conditions/MC09-20090602-vo-md100.py;$APPCONFIGOPTS/Brunel/veloOpen.py
      DDDb: MC09-20090602
      ConDDb: sim-20090402-vo-md100
Step3:LHCb-v28r0
      Option files: $STDOPTS/PoolCopy.opts
      DDDb: MC09-20090602
      ConDDb: sim-20090402-vo-md100
Number of Steps   1
Total number of files: 2
         LOG:1
         DST:1
Number of events [('DST', 53453)]
Path:  /MC/MC09/Beam450GeV-VeloOpen-MagDown-Nu1/MC09-Brunelv35-withTruth/None
/MC/MC09/Beam450GeV-VeloOpen-MagDown-Nu1/MC09-Brunelv35-withTruth/None/DST

Under the different steps you find the DDDb tags and the ConDDb tags, i.e. 'DDDb: MC09-20090602', 'ConDDb: sim-20090402-vo-md100' for the example file.

It can happen, that the info reported by dirac-bookkeeping-production-informations lists None as database tags:

Production Info: 
    Configuration Name: MC
    Configuration Version: MC11a
    Event type: 11144103
-----------------------
 StepName: Merge12 for MC11 
    ApplicationName    : LHCb
    ApplicationVersion : v33r1
    OptionFiles        : $APPCONFIGOPTS/Merging/CopyDST.py
    DDB                : None
    CONDDB             : None
    ExtraPackages      : AppConfig.v3r118
-----------------------

In this case the production information got lost while merging. You can have a look at the database tags used for the merge job and hope they where correct

SetupGauss
cat $GAUSSROOT/options/Gauss-MC11a.py

When using real data, you need a DDDB tag (DDDB) and a CondDB (LHCBCOND) tag.

Insert the following lines to your options file:

DaVinci().CondDBtag = "head-20091211"
DaVinci().DDDBtag = "head-20091120"

When running over Monte Carlo data, you need a DDDB tag (DDDB) and a CondDB (SIMCOND) tag.

DaVinci().CondDBtag = "sim-20090402-vo-md100"
DaVinci().DDDBtag = "MC09-20090602"

• Note: There is nothing like “DaVinci().SimCond”, the corresponding information has to be written in the “CondDBtag”.
• It may sometimes be necessary to access the OracleDB. This can be achieved the following way:

from Configurables import CondDB
CondDB(UseOracle = True)

You can find a file including dictionaries of all yet known (and at least often used) tags under: “/afs/cern.ch/user/e/elsasser/public/dbtags/tagdict.py” which can be imported to be used in a python script. The base file is located under “/afs/cern.ch/user/e/elsasser/public/dbtags/prodFileList.txt”

Look at the stdout file of your job: After the start of Loki you will find something like the following statements:

DDDB                 INFO Connected to database "sqlite_file:/afs/cern.ch/project/gd/apps/lhcb/lib/lhcb/DBASE/Det/SQLDDDB/v5r17/db/DDDB.db/DDDB"
DDDB                 INFO Using TAG "MC09-20090602"
SIMCOND              INFO Connected to database "sqlite_file:/afs/cern.ch/project/gd/apps/lhcb/lib/lhcb/DBASE/Det/SQLDDDB/v5r17/db/SIMCOND.db/SIMCOND"
SIMCOND              INFO Using TAG "MC09-20090402-vc-md100"

Follow this link: http://lhcb-release-area.web.cern.ch/LHCb-release-area/DOC/dbase/conddb/release_notes.xml

"Recommended Tags" Page in TWiki