CAST does not work in some cases due to bugs in Calcite unparsing

For example:

"CAST(xxx AS TIMESTAMP)" is unparsed to "CAST(xxx AS TIMESTAMP(0))"

The fix is already in the newest version of BigQuerySqlDialect.java in Calcite (using SqlAlienSystemTypeNameSpec), so this issue will be fixed after we update our vendored Calcite version.

I tried to patch the change to BeamBigQuerySqlDialect.java (similar to what we did for other features) but this change is very large (multiple new classes) to patch.

cc: apilloud