How to list all hive databases being in use or created so far?
This page mentions the command SHOW DATABASES.
From the manual:
SHOW (DATABASES|SCHEMAS) [LIKE identifier_with_wildcards];SHOW DATABASES lists all of the databases defined in the metastore. The optional LIKE clause allows the list of databases to be filtered using a regular expression. Wildcards in the regular expression can only be '' for any character(s) or '|' for a choice. Examples are 'employees', 'emp', 'emp*|*ees', all of which will match the database named 'employees'.