ctxkbtc Constraints on Thesaurus Relations

The following constraints apply to thesaurus relations:

• BTG and BTP are the same as BT. NTG and NTP are the same as NT.

• Only preferred terms can have a BT, NTs or RTs.

• If a term has no USE relation, it will be treated as its own preferred term.

• If a set of terms are related by SYN relations, only one of them may be a preferred term.

• An existing category cannot be made a top term.

• There can be no cycles in BT and NT relations.

• A term can have at most one preferred term and at most one BT. A term may have any number of NTs.

• An RT of a term cannot be an ancestor or descendent of the term. A preferred term may have any number of RTs up to a maximum of 32.

• The maximum height of a tree is 16 including the top term level.

• When multiple thesauri are being compiled, a top term in one thesaurus should not have a broader term in another thesaurus.

  Note:

  The thesaurus compiler tolerates some violations of the preceding rules. For example, if a term has multiple BTs, then the compiler ignores all but the last one it encounters.

  Similarly, BTs between existing knowledge base categories result only in a warning message.

  Oracle recommends that you do not set up extended storage bases with violations. Using extended storage bases containing violations can produce undesired results.