CHAIN is used for random retrieval from a File. In other words, WHATEVER value used by programmer in Factor 1/Key against CHAIN opcode will be used as search/find criteria in database file. NO VALUE RETRIEVED IN NO CRITERIA MATCH. It can be well understand, in case of using composite keys.

But in case of SETLL and SETGT, program will return some value, if any value present in the database/physical file.

• CHAIN = Sets pointer on exact value
• SETLL = Sets pointer on Lower Limit of the value
• SETGT = Sets pointer on Greater Limit of the value

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It is RECOMMENDED, use CHAIN only, if RECORD EXIST in database file, instead of SETLL and SETGT, which can be used otherwise.

CHAIN is used for random retrieval from a File. In other words, whatever value used by programmer in Factor 1/Key against CHAIN opcode will be used as search/find criteria in database file. NO VALUE RETRIEVED IN NO CRITERIA MATCH. It can be well understand, in case of using composite keys.

But in case of SETLL and SETGT, program will return some value, if any value present in the database/physical file.

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It is recommended, use CHAIN only, if record exist in database file, instead of SETLL and SETGT, which can be used otherwise.