There exists structures for supporting this in the metastore, but that feature isn't in Hive yet. For example, although the metadata for partitions include its own set of columns, parts of the code in the query processor still read from table level metadata.
Some evolution can occur in the form of adding columns to a table. -----Original Message----- From: Yang [mailto:[email protected]] Sent: Thursday, July 01, 2010 4:43 PM To: [email protected] Subject: Schema evolution? I read on the VLBD hive paper "Hive - A Warehousing Solution Over a Map-Reduce Framework" that Partitions could have different schemas : (section 3.1 MetaStore) " Partition - Each partition can have its own columns and SerDe and storage information. This can be used in the future to support schema evolution in a Hive warehouse. " but the API: http://hadoop.apache.org/hive/docs/r0.5.0/api/ only lists getSchema() for Table, and Partition does not have a separate getSchema(). is the schema evolution feature really there? Thanks Yang
