Why for metastore RDBMS is used

Question

Hi,

I am learning hive and got a query that a RDBMS is used as a metastore in the hive, where hive is not an RDBMS. Then why for metadata RDBMS is used? Can anyone explain this?

Answer 1

Hey,

Yes, it is correct that Hive is not an RDBMS, but because the response from the RDBMS is much less that is latency is much less compared to Hadoop HDFS. For syntax and semantic analysis or validation for your query, even in the execution engine, it contains the metastore before executing your queries, so all these responses to speed up the processing between these components an RDBMS is used as a metastore here in Hive.