Extensions to SQLAlchemy ImpalaDLLCompiler to support Alembic schema migrations (#441)
Extensions to SQLAlchemy ImpalaDLLCompiler to support Alembic schema migrations (#441)

* Extend ImpalaDLLCompiler to prevent CONSTRAINT and NOT NULL clauses being added to CreateTable DDL; and translate all "string" types to STRING and "datetime" types to TIMESTAMP.

* Add support for PARTITIONED BY clause in CREATE TABLE statements

* Impala > 3.4.0 support the DATE type - https://issues.apache.org/jira/browse/IMPALA-6169

* Mention Impala's limited primary/foreign key support - https://issues.apache.org/jira/browse/IMPALA-2112

* Only translate TEXT, NCHAR and NVARCHAR types to STRING, as  VARCHAR and CHAR types are supported in Impala >= 2.0

* Translate all date* types to TIMESTAMP

Co-authored-by: David Laing <51fc871882fe42812090bab2d216608aa1957c6a@vmware.com>
cloudera/impyla,cloudera/impyla