Q1
What are KSDS, ESDS, RRDS, and LDS?
KSDS: Key sequenced, unique key, random/sequential access. ESDS: Entry sequenced, no key, RBA access. RRDS: Relative record, slot number access. LDS: Linear, byte stream.
Q2
What causes file status 23?
Record not found for READ/START/DELETE. Key doesn't exist. Verify key value, handle not-found condition in program logic.
Q3
Explain REPRO utility.
REPRO copies VSAM files. Can copy between VSAM and sequential. Options: FROMKEY/TOKEY, SKIP/COUNT, REPLACE. Used for backup, conversion.
Q4
How to handle file status 35?
File not found. Check: DSN spelling, catalog entry exists, file created. Add DD statement if missing.
Q5
Explain KSDS key definition.
KEYS(length offset). Length up to 255. Offset from position 0. Key extracted from record. Must be unique. Alphanumeric comparison.
Q6
What causes file status 22?
Duplicate key on WRITE. KSDS primary key must be unique. Check data, use REWRITE for updates instead.