21⟩ How does IDMS insure data integrity?
IDMS uses record locks to prevent another run-unit from updating the same record.
IDMS
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“IDMS Interview Questions and Answers will guide us now that IDMS (Integrated Database Management System) is a (network) CODASYL database management system first developed at B.F. Goodrich and later marketed by Cullinane Database Systems, So start preparation for the job of IDMS by the help of this IDMS Interview Questions with Answers guide”
33 IDMS Questions And Answers
22⟩ What is autostatus in IDMS?
Autostatus is a protocol mode which causes the expansion of each DML statement to include a 'perform IDMS-Status' statement.
23⟩ What is the meaning of Copy IDMS Subschema-Binds in IDMS?
It generates a bind run-unit and binds all the records for the sub-schema the program is referencing.
24⟩ What is the IDD in IDMS?
IDD is the Integrated Data Dictionary. It contains information about the elements, record types, sets, maps and dialogues within the database.
25⟩ What is the meaning of the return codes 0307 and 0326?
0307 is end-of-set and 0326 is record not found.
26⟩ What does a FINISH do in IDMS?
It releases all database resources, terminates database processes, writes statistical information to IDMS and logs the checkpoint.
27⟩ What does a COMMIT statement do?
It writes a checkpoint to the Journal File and releases any record locks.
28⟩ What is the purpose of a READY?
The READY prepares a database area for access by DML functions.
29⟩ What does a ROLLBACK do in IDMS?
It rolls back (reverses) all database updates to the point of the last rollback or to the beginning of the run-unit.
30⟩ What is a set in IDMS? What pointers are required, what are possible? How may sets be ordered?
A set is an owner record and, optionally, its member records. There are three types of pointers: next, prior and owner, but only next is required. There are five possible orders for arrangements of sets; they are: first - insert at beginning, last - insert at end of set, next - insert after current of set, prior - insert prior to current of set and sorted - insert according to sort value.
31⟩ Name and explain the three location modes?
Calc is based on a symbolic value which is used to determine the target page. Via mode is for members only. Via records are stored near to their owners.
In direct mode the target is specified by the user and is stored as close as possible to that page.
32⟩ What is the meaning of Copy IDMS Subschema-Binds?
It generates a bind run-unit and binds all the records for the sub-schema the program is referencing.
33⟩ What is a junction record in IDMS?
A junction record is a member record type that allows for many-to-many relationship between its two owner records.
