Is the ISN always greater than zero?

Hello all!

Just a stupid question: Is the ISN of an ADABAS-Record always > 0 ?

I know about a special meaning of ISN in connection to the NATURAL Historgram-Command (IIRC Adabas command “L9”). Are there any other special cases where ISN can be zero or even negative?

Kind regards,


YES, every Adabas record, when stored, gets its unique ISN > 0.

Thanks! I think that’s what NAT3113 is trying to tell me.
The reason for asking this question was: *ISN (inside a Natural Histogram-loop) can be zero even if some records are available. But if I understand you correctly, an ISN less or equal zero can’t be a “real” record.

*ISN on a HISTOGRAM does not return the ISN, because the purpose of a HISTOGRAM is to tell you the number of records with a given descriptor value.

On a HISTOGRAM *ISN is used to tell you the occurrence within a PE in which the descriptor is contained. It will be 0 for all descriptors not contained in a PE !