Cloudera Impala has the following SQL restrictions:
Column values and parameters are always nullable.
No support for row-level updates or deletes
No support for stored procedures
No ROWID support
No support for materialized views
No support for synonyms
Primary and foreign keys are not supported.
Support for indexes is incomplete.
A single quote within a string literal must be escaped using a \ instead of using a single quote. Because string literals can be expressed with either single or double quotation marks, Impala's would be written as 'Impala\'s' or "Impala\'s".
Column values and parameters are always nullable.