No Matching Buffer Error - Orphaned Data

I recently came across an issue where I tried accessing a component and received an error stating

No matching buffer found for level. (15,26)

This was because orphan data existed.  I had updated an sqr to delete data from a sql table that was a parent table.  This parent table had child tables.  Since I did not delete the related data from the child tables too the data didn't match up between the levels. 

So what I learned from this was to check if a parent record has child records when deleting data.  A query that identifies child records is shown below:

SELECT * FROM PSRECDEFN WHERE PARENTRECNAME = {tablename};

A query for pulling the orphaned data from the child table is shown below:

select * FROM {child_record}  A
WHERE NOT EXISTS
(SELECT 'x' FROM {parent_record} B 
WHERE A.{key_field}=B.{key_field});

Oracle has some related documentation online.  I believe they have a delivered component that can clean up orphan data from batch processes.