Most of the times the foreign keys are not defined on Siebel database so give speed (at least on Oracle Server). Siebel maintains the FK ties to these tables :
src -müzso - SQL Server - Find references to a record of a Siebel table in all of its foreign key tables
SQL:
--show where table is referenced
select base_table.name as base_table, c.name as column_name, ref_table.name as reference_table from siebel.s_column c
left join siebel.s_table base_table on base_table.row_id = c.tbl_id
left join siebel.s_table ref_table on ref_table.row_id =c.fkey_tbl_id
where ref_table.name = 'S_PARTY'
order by 2
--show table references
select base_table.name as base_table, c.name as column_name, ref_table.name as reference_table from siebel.s_column c
left join siebel.s_table base_table on base_table.row_id = c.tbl_id
left join siebel.s_table ref_table on ref_table.row_id =c.fkey_tbl_id
where base_table.name = 'S_PARTY' and ref_table.name is not null
order by 2
src -müzso - SQL Server - Find references to a record of a Siebel table in all of its foreign key tables