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Error reporting and recovery in Sangrah
Author(s) -
Prakash Naveen,
Gejji P. N.
Publication year - 1981
Publication title -
software: practice and experience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 70
eISSN - 1097-024X
pISSN - 0038-0644
DOI - 10.1002/spe.4380110605
Subject(s) - statement (logic) , computer science , base (topology) , scheme (mathematics) , state (computer science) , differential (mechanical device) , programming language , algorithm , arithmetic , database , mathematics , engineering , political science , law , mathematical analysis , aerospace engineering
In Sangrah, exception conditions of CODASYL have been replaced by fatal errors and by boolean valued functions. Fatal errors can occur either because all the preconditions necessary for a DML statement are not fulfilled or because of the state of the data base at the time when this statement is executed. A mechanism which anticipates the former situation and thereby saves the data base from corruption is presented. Another recovery scheme which protects the data base from an abnormal termination of the user program is also described. This scheme uses a differential file.