VSAM Interview questions 10-20

• Q11: What is the purpose of the FILE STATUS clause in the SELECT statement?
  • Answer : The FILE STATUS field identifies the field that VSAM uses to provide information about each I/O operation for the file.
  Q12: Explain the meaning and syntax for the START command.
  • Answer : The START command is used read other than the next VSAM record. A value must be moved into the RECORD KEY. The KEY clause is optional, but it can be used to specify a relational (equal, less than, etc.) operator.
  Q13: What is the meaning of dynamic processing?
  • Answer : It's rarely used. It means one program uses both sequential and random processing for a VSAM KSDS file
  Q14: What is a VSAM slot?
  • Answer : A relative record dataset (RRDS) consists of a specified number of areas called slots. Each slot is identified by a relative record number (RRN) which indicates its relative position in the file.
  Q15: What are the three levels of definition for the VSAM DEFINE?
  • Answer : They are DEFINE CLUSTER, DATA and INDEX.
  Q16: What is the meaning of the DEFINE MODEL parameter?
  • Answer : It specifies whether Daniela Pestova or Yamila - oops! Wrong models! The MODEL parameter allows you to model your cluster by modeling it after an existing cluster.
  Q17: What is IDCAMS ?
  • Answer : IDCAMS is the Access Method Services program. You run the IDCAMS program and supply AMS commands thru SYSIN. (examples of AMS commands are DELETE, DEFINE, REPRO etc..).
  Q18: Can AMS commands be run from the TSO prompt ?
  • Answer : Yes
  Q19: What is FREESPACE ?
  • Answer : Coded in the DEFINE as FREESPACE(ci ca) where ci is the percentage of each control interval to be left free for insertions, ca is the percentage of control intervals in each control area to be left empty.
  Q20: Assuming that the DEFINE JCL is not available, how do you get info about a VSAM file's organisation?
  • Answer : Use the LISTCAT command