问题
I need to do some SQL queries (as here) directly from Metasore.
PS: the commands SHOW/DESCRIBE are not enough.
How to enable access from it as database, or what the database name of Metastore? ... In nowadays (2019) it is possible?
NOTES
What is Metastore?
For me is a very important element of the Hive architecture, final user need some access to it... "All Hive implementation need a metastore service, where it stores metadata. It is implemented using tables in relational database. By default, Hive uses built-in Derby SQL server", 1.
Of course, you need in your context a "standard" Metastore. On my corporation's Hadoop cluster we are planning to standardize Metastore (local and long term standard), perhaps PostgreSQL and also an (PostgREST API for external consume of some SQL-Views from it).The SQL definitions (table names, etc.) will be stable and Metastore queries will be reliable when Metastore is a long-term local standard.
The Metastore it is closely connected to Hive, where it is a Java API, but Metastore is also a standard RDBMS and offers standard connection (by SQL) for the external universe.
PS: my interest on Metastore is in this external context.
回答1:
Spark-shell solution
Spark access Metastore under the hood, it have a first class metadata method, that returns a dataframe, the schema property, that expose names, types, etc. and offers getComment method.
See https://stackoverflow.com/a/57857021/287948
来源：https://stackoverflow.com/questions/57401967/how-to-access-metastore-from-beeline