Size limits on fields

Many software systems use RDBMS technology that uses fixed-length fields. In order to cater for these systems, LISS has specified a maximum size for certain types of fields. The limit is only applied to “reference fields”, that is, fields which need to be matched between 2 different RPC calls or fields which might be used as keys in the receiving system, e.g. ClassCode, TeacherCode, StudentId. Non-reference fields, such as student FirstName, can be any length, and the expectation is that the receiving system will truncate it if it is too long.

The limit is 20 for all id and code fields, and 10 for “class identifier”, which is the 2nd component of ClassCode.

Limits are specified in the field descriptions. If there is no mention of a limit then there is no limit on that type of field.

This limitation is a compliance requirement, however any given pair of systems can choose to go beyond these limits.

(There was some discussion about whether the limit should be 32, large enough to store a UUID, but the consensus was that UUID’s are unlikely to replace the id fields as envisaged here and that a limit of 20 lowers the bar for systems to become compliant.)