Error in reading from table after doing an alter column type

Steps to repoduce:
```
CREATE FOREIGN TABLE simpleTable (simpleColumn int) SERVER cstore_server;
INSERT INTO simpleTable SELECT * FROM generate_series(1,100000);
ALTER TABLE simpleTable ALTER COLUMN simpleColumn TYPE float ;
SELECT * FROM simpleTable;
```

The select query in the end produces this error stating " ERROR: insufficient data left in datum buffer"
All queries other than the select query ran without errors