DrillConvertletTable is used as a way to have custom functions. For example, for EXTRACT(), DrilLConvertletTable.get() returns DrillExtractConvertlet, which returns a custom RexNode for the extract function.
On the other hand, DrillAvgVarianceConvertlet is never used. stddev/avg/variance functions are handled by DrillAggregateRule and DrillReduceAggregatesRule.
- relates to
DRILL-7406 Update Calcite to 1.21.0
- links to