This query listed tables that have no foreign keys, meaning they are not referencing any table or are not on the "many" side of FK.

Query below lists something a little different - tables that are not referencing and are not referenced by other tables. Something we called Loner Tables. This diagram illustrates the concept:

Learn more about Loner Tables

Query

select table_count,
    loner_tables,
    cast(100 * loner_tables / table_count as decimal (14,2)) concat '%' 
    as loner_ratio
from
(select 
    count(distinct tab.tabschema concat '.' concat tab.tabname) 
    as table_count,
    sum(
        case when  const.constname is null and  ref.constname is null then 1
        else 0 end) as loner_tables
    from 
    syscat.tables tab
    left outer join syscat.tabconst const 
        on const.tabschema = tab.tabschema 
        and const.tabname = tab.tabname and const.type ='F'
    left outer join syscat.references ref 
        on ref.reftabschema = tab.tabschema  
        and ref.reftabname = tab.tabname 
    where 
        tab.type ='T'
        and tab.tabschema not like 'SYS%'
) loner_ratio  

Columns

• table_count - number of tables in database
• loner_tables - number of Loner Tables in the database
• loner_ratio - Loner Ratio - % of Loner Tables in the database

Rows

• Scope of rows: query returns one row

Sample results

Loner Ratio in GSDB database is 9% - i.e. 9% of tables are not related with FKs to any other table.