This JIRA is for PR https://github.com/apache/calcite/pull/545
We are making the HiveSqlDialect version aware for the NULLS FIRST and NULLS LAST feature. In https://issues.apache.org/jira/browse/HIVE-12994 , the authors clarified that the default NullCollation for Hive is "NullDirection.LOW". Currently, the DEFAULT set in Calcite for Hive is NullCollation.HIGH
In this PR, we are making 2 changes.
- Change the default NullCollation from HIGH to LOW
- Add NullCollation emulation in the HiveSqlDialect when the version of the dialect is less that 2.1.0 or when the version is blank.
We're also adding a new Dialect "BigQuerySqlDialect" with the "quoteString" as "`" based on https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical