Apache Impala Reference

Authentication options and data type handling for Impala connections.

Authentication

Variable	Example	Description
DATACONTRACT_IMPALA_USERNAME	analytics_user	Username
DATACONTRACT_IMPALA_PASSWORD	mysecretpassword	Password
DATACONTRACT_IMPALA_USE_SSL	true	Whether to use SSL (defaults to true)
DATACONTRACT_IMPALA_AUTH_MECHANISM	LDAP	Authentication mechanism (defaults to LDAP)
DATACONTRACT_IMPALA_USE_HTTP_TRANSPORT	true	Whether to use HTTP transport (defaults to true)
DATACONTRACT_IMPALA_HTTP_PATH	cliservice	HTTP path for the Impala service (defaults to cliservice)

host, port, and database come from the contract's servers block.

Data types

Importing

There is no direct Impala importer. Import a SHOW CREATE TABLE DDL with datacontract import sql --dialect spark (Impala DDL is Hive-compatible): STRING/VARCHAR/CHAR → string, INT/BIGINT/SMALLINT/TINYINT → integer, FLOAT/DOUBLE/DECIMAL → number, BOOLEAN → boolean, DATE → date, TIMESTAMP → timestamp, ARRAY<...> → array, STRUCT<...> → object, BINARY → string (format binary), MAP<...> → no logical type.

Testing

Impala does not support native type introspection — the declared physicalType is not compared against the catalog. Instead, the logicalType is checked by category (Check that field x has type y): the actual column type is normalized to one of the nine ODCS categories and compared, with integer and number treated as compatible.