No, they would not be left empty. one record will be written in each CI and 1 CI will be written for each CA.
The Index and data components of a KSDS
The answer is : 1
By USING RBA (Relative Byte Address).
FREE SPACE ( FPSC )
2 data buffers by default for ESDS. For KSDS it allots 2 data buffers and 1 index buffers. each buffer is about 4K.
An alternate index is an another way of accessing key sequenced data record stored in a base cluster and path is the linkage which connect alternate index to its base cluster.
No delete operation is not possible in VSAM ESDS.B. yes rewrite operation is possible in an ESDS.