HIVE-2915: Partitioned Tables in Hive Metastore

[Matt Tucker]

Hi,

I'm currently using CDH3u3 and Hive 0.7.1, and I'm looking into how the
metadata is stored for partitioned tables within the RDBMS.

The issue that I see is that for tables with multiple partitioning columns,
there's no good way to determine which PARTITION_KEY_VALS record maps to
it's logical PARTITION_KEYS record.  I'd like to avoid trying to parsing
the PARTITIONS.PART_NAME field, as I'm unaware of anything like LATERAL
VIEW(EXPLODE()) in MySQL.


Sample metastore query:
SELECT
  DBS.NAME,
  TBLS.TBL_NAME,
  TBLS.OWNER,
  PARTITION_KEYS.PKEY_NAME,
  PARTITIONS.PART_ID,
  PARTITIONS.PART_NAME,
  PARTITION_KEY_VALS.PART_KEY_VAL
FROM DBS
  INNER JOIN TBLS ON
    DBS.DB_ID = TBLS.DB_ID
  INNER JOIN PARTITION_KEYS ON
    TBLS.TBL_ID = PARTITION_KEYS.TBL_ID
  INNER JOIN PARTITIONS ON
    TBLS.TBL_ID = PARTITIONS.TBL_ID
  INNER JOIN PARTITION_KEY_VALS ON
    PARTITIONS.PART_ID = PARTITION_KEY_VALS.PART_ID
ORDER BY DBS.NAME, TBLS.TBL_NAME, PARTITIONS.PART_NAME;

Thanks

Matt