TDMcreates a duplicate index for a Primary Key field when Create Index to Foreign Keys is selected.
ALTER TABLE XYZ_REF ADD CONSTRAINT pk_XYZ_REF PRIMARY KEY (IMPORT_REF_TYPE_ID)
USING INDEX TABLESPACE TBS_ABC_LIVE_IDX
CREATE INDEX XP_CAR_LRR_EXISTS ON XYZ_REF (IMPORT_REF_TYPE_ID)
It is not possible to exclude a single table from generating XP_ constraints.
This issue has a significant impact TDM (Toad Data Modeler) as the option available is to manually modify SQL script generated by TDM.
Edit identifying relationship and uncheck the Create Index to Foreign Key check box.
If you wish to uncheck checkboxes for all identifying relationships, he can download a script from our community site.