Let's say I have 1200 tables and 20 tables went missing. How to find which tables are those?
If you are taking backup of the metastore, you can compare between the current and the backup metastore (TBLS table) and get the requried information.
I dont think there is a default option to find out the missing tables. Only way to do is to compare the previous version of metastore with the current version. Also backup of the previous metastore has to be archived before the deletion of the tables only then you will be able to compare and find out the missing tables. The other way but doesnt work most of the times. Sometimes if the tables are deleted and if the Hcatalog/hive metastore is not updated then you will be able to find out easily. Hope it helps!