ImmutableMap.Builder<Symbol, ColumnHandle> inputColumnsBuilder = ImmutableMap.builder();
ImmutableList.Builder<Field> fields = ImmutableList.builder();
ImmutableList.Builder<ColumnHandle> columnHandleBuilder = ImmutableList.builder();
for (ColumnMetadata column : sourceTableMetadata.getColumns()) {
Field field = Field.newQualified(sourceTable.asQualifiedName(), Optional.of(column.getName()), Type.fromRaw(column.getType()));
Symbol symbol = symbolAllocator.newSymbol(field);
inputColumnsBuilder.put(symbol, sourceTableColumns.get(column.getName()));
ColumnHandle targetColumnHandle = targetTableColumns.get(column.getName());
fields.add(field);