The Computational Materials Repository

40 Introduction and usage of CMRAAf i n a l . t r a ji n i t i a l . t r a jThe status can be checked with --status:$ cmr −−s t a t u s .cmr v e r s i o n 0 . 3 . 2 . 5 2 3Ms t a t u s | d b o r i g f n | d b l a s t m o d i f i e d | db keywords | db hashA | i n i t i a l . t r a j | 2011−12−09 2 3 : 1 . . . | NULL | 78169 b4 . . .A | i n i t i a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ f i r s t ’ ] | 8 bf505e . . .A | i n i t i a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ l a s t ’ ] | eeb029a . . .A | f i n a l . t r a j | 2011−12−09 2 3 : 1 . . . | NULL | 5 4 8 2 0 9 . . .A | f i n a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ f i r s t ’ ] | daf1eb2 . . .A | f i n a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ l a s t ’ ] | a2c288e . . .6 columns .The “A” in front signals that the files are scheduled to be uploaded. It is nowpossible to edit the files with --modify exactly the same way as previouslyshown:$ cmr −−modify i n i t i a l . t r a jwith the exception that --status is used to see the files. When done --commitis used in order to upload them to the db-file repository:$ cmr −−commit ∗ . t r a jAs soon as the files are available in the database, using --status shows thestatus “DB”s t a t u s | d b o r i g f n | d b l a s t m o d i f i e d | db keywords | db hashDB | i n i t i a l . t r a j | 2011−12−09 2 3 : 1 . . . | NULL | 78169 b4 . . .M DB | i n i t i a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ f i r s t ’ ] | 8 bf505e . . .DB | i n i t i a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ l a s t ’ ] | eeb029a . . .DB | f i n a l . t r a j | 2011−12−09 2 3 : 1 . . . | NULL | 5 4 8 2 0 9 . . .DB | f i n a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ f i r s t ’ ] | daf1eb2 . . .DB | f i n a l . t r a j | 2011−12−09 2 3 : 1 . . . | [ ’ l a s t ’ ] | a2c288e . . .6 columns .unless the file was modified meanwhile in which case it would be “M DB”.The CLI has clear advantages when working directly with db-files: the accessis fast and easy, but the drawback is that it is not very flexible: all actions arebased on file names and are not programmable like in the python interface.2.6 Modifying Data in the DatabaseThere are a few important details about duplicates, overwriting and removal ofdata from the database. In a file system there can be only one files with a certainname per directory. CMR works in a similar way, but instead of a file name, aunique identifier (UI) is calculated using a hash function over the static partof the included data. The static part is mainly the output of the calculator and