Page History

...

For more information, see Metastore Schema Consistency and Upgrades.

hive.metastore.disallow.incompatible.col.type.changes

• Default Value:
  • Hive 0.x and 1.x: false 
  • Hive 2.x and later: true
    
• Added In: Hive 0.12.0 with HIVE-4409

If true (default is false), ALTER TABLE operations which change the type of
+ a column (say STRING) to an incompatible type (say MAP<STRING, STRING>) are disallowed.
+ RCFile default serde (ColumnarSerde) serializes the values in such a way that the
+ datatypes can be converted from string to any type. The map is also serialized as
+ a string, which can be read as a string as well. However, with any binary
+ serialization, this is not true. Blocking the ALTER TABLE prevents ClassCastExceptions
+ when subsequently trying to access old partitions.
+
+ Primitive types like INT, STRING, BIGINT, etc are compatible with each other and are
+ not blocked.
+
+ See HIVE-4409 for more details.

hive.metastore.integral.jdo.pushdown

• Default Value: false
• Added In: Hive 0.13.0 with HIVE-6052

...