Is it possible to detect which table is what data changed in oracle materialized view using trigger?

Question

I have a materialized view and I want to detect:

• when materialized view is updated
• which table(s)'s
• what data's (or row) changed?

Answer 1

If you are using a MV log there should already be a trigger on the base table(s) and the triggers an populating the material view log (actually its a table) This would assume that you are doing fast refreshes instead of complete refreshes. Check the following tables to see if they contain the information that you are looking for:

select trigger_name from user_triggers
where table_name = '<you table name>'

SELECT master, log_table, rowids, primary_key
FROM user_snapshot_logs;

desc mlog$_<your table name>

desc rupd$_<your table name>

The mlog$_... and rupd$... name may get truncated in case the base table's name is too long. Hope that helps you.