Hi, Lekshmi ~
The FilterableTable can be scanned with a list of filter expression, that means the filter conditions above the project + scan can be pushed directly into the table scan[1][2], which is more efficient. Here is a CsvFilterableTable example [3]. [1] https://github.com/apache/calcite/blob/602b2a10e3f81888c0759ca69f7415497124ef82/core/src/main/java/org/apache/calcite/rel/rules/FilterTableScanRule.java#L130 [2] https://github.com/apache/calcite/blob/602b2a10e3f81888c0759ca69f7415497124ef82/core/src/main/java/org/apache/calcite/rel/rules/ProjectTableScanRule.java#L128 [3] https://github.com/apache/calcite/blob/602b2a10e3f81888c0759ca69f7415497124ef82/example/csv/src/main/java/org/apache/calcite/adapter/csv/CsvFilterableTable.java#L65 Best, Danny Chan 在 2019年8月8日 +0800 PM10:56，dev@calcite.apache.org，写道： > > Filterable
