private void reduceCasts(RexCall outerCast) { RexNode[] operands = outerCast.getOperands(); if (operands.length != 1) { return; } RelDataType outerCastType = outerCast.getType(); RelDataType operandType = operands[0].getType(); if (operandType.equals(outerCastType)) { removableCasts.add(outerCast); return; } // See if the reduction // CAST((CAST x AS type) AS type NOT NULL) // -> CAST(x AS type NOT NULL) // applies. TODO jvs 15-Dec-2008: consider // similar cases for precision changes. if (!(operands[0] instanceof RexCall)) { return; } RexCall innerCast = (RexCall) operands[0]; if (innerCast.getOperator() != SqlStdOperatorTable.castFunc) { return; } if (innerCast.getOperands().length != 1) { return; } RelDataTypeFactory typeFactory = preparingStmt.getFarragoTypeFactory(); RelDataType outerTypeNullable = typeFactory.createTypeWithNullability(outerCastType, true); RelDataType innerTypeNullable = typeFactory.createTypeWithNullability(operandType, true); if (outerTypeNullable != innerTypeNullable) { return; } if (operandType.isNullable()) { removableCasts.add(innerCast); } }