Cloudera Docs

Supported Data Types and limitations

Learn about supported data types and limitations for external JDBC tables in Impala.

The following column data types are supported for an external JDBC table:
  • Numeric data type: boolean, tinyint, smallint, int, bigint, float, double
  • Decimal with scale and precision
  • String type: string
  • Date
  • Timestamp

Limitations

  • Unsupported column data types: char, varchar, binary. Complex data type - struct, map, array, and nested type
  • JDBC tables have to be defined one table at a time
  • Writing to a JDBC table is not supported
  • Only support binary predicates with operators =, !=, <=, >=, <, > to be pushed to RDBMS