Address support on postgresql

Author: amol-

src/mustela/translation/optimizer.py

@@ -174,8 +174,9 @@ def fold_case(self, expr: ibis.Value | ibis.Deferred) -> ibis.Value:
             else:
                 return op.default.to_expr()
         elif len(op.cases) == 1 and results_are_literals and possible_values == {1, 0}:
-            # results are 1 or 0, we can fold it to a boolean
-            # expression.
+            # results are 1 or 0, we can fold it to a boolean expression.
+            # FIXME: This doesn't work on postgresql so we need to disable it for the moment.
+            return expr
             if op.results[0].value == 1:
                 return (op.cases[0].to_expr()).cast("float64")
             else:

src/mustela/translation/steps/onehotencoder.py

@@ -32,11 +32,9 @@ def process(self) -> None:
             raise ValueError("OneHotEncoder: input expression not found")
 
         casted_variables = [
-            self._optimizer.fold_cast(
-                typing.cast(ibis.expr.types.BooleanValue, (input_expr == cat)).cast(
-                    "int"
-                )
-            ).name(self.variable_unique_short_alias("onehot"))
+            ibis.ifelse(input_expr == cat, 1.0, 0.0).name(
+                self.variable_unique_short_alias("onehot")
+            )
             for cat in cats
         ]