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[naveen]

How Variable-length RRDS is different from RRDS? (apart from being Variable length)

[kolusu]

Naveen,

A VRRDS is similar to a fixed-length RRDS, except that it contains variable-length records. Each record has a unique relative record number, and is placed in ascending relative record number order. Each record is stored and retrieved using its relative record number. VRRDS has no slots. The relative record number of a record cannot change. When that record is
erased, the relative record number can be reused for a new record. You can specify free space for inserting records and increasing the length of a record. VRRDS is a KSDS processed as an RRDS, so an index will be created.

Fixed-Length RRDS:

• Records are in relative record number order
  
• Records have fixed length
  
• Direct access by relative record number
  
• Consists of Data component only
  
• No Alternate index is allowed
  
• A record's relative number cannot be changed
  
• Empty slots in the dataset are used for adding records
  
• A slot given up by deleted record can be reused
  
• No spanned records
  
• Extended format is allowed
  

Variable-Length RRDS:

• Records are in relative record number order
  
• Records have variable length
  
• Direct access by relative record number
  
• Consists of Data and Index components
  
• No Alternate index is allowed
  
• A record's relative number cannot be changed
  
• Freespace is used for inserting and lengthening records
  
• Space given by deleted or shortened record becomes free space
  
• No spanned records
  
• Extended format is allowed
  

Hope this helps...

cheers

kolusu