When you import a dataset, Wrangler infers the source data types and maps them to the corresponding Wrangler data types. Wrangler data types are internal data types based on Java data types. The inferred data types appear at the top of each column on the Data page.
...
Changing String to
...
To change a column to Integer, all values in the column must be of type Integer. If you try to change a String column with a mix of Integers and Decimals to Integer, the conversion fails with an error message.
Changing String to Boolean
If you change a String to Boolean, all values in the column are set to FALSE.
If you change an Integer to Boolean, 1 is set to TRUE. 0 and all other values are set to FALSE.
BigQuery and Wrangler data types
Wrangler doesn’t support the following BigQuery data types:
...