jackye1995 commented on PR #6611:
URL: https://github.com/apache/iceberg/pull/6611#issuecomment-1386354696

   > I think the reason it was optional is to support cases where views are 
created via API rather than by a SQL parser
   
   Nice that we are clarifying this now. If we support this case of no schema, 
it means the view will "auto-update" itself when the source table schemas 
change. This might be a good thing or bad thing depending on the use case. 
   
   I think in most database systems at this moment, view schema is fixed at 
creation time. For example, if we support this in Trino, since we cannot derive 
the schema and cannot fulfill the `List<ViewColumn> columns` part of the 
`ConnectorViewDefinition`, we will fail at`checkViewStaleness`. Core Trino 
logic needs to be updated to support this case, but it is still achieveable.
   
   I also checked mySQL, 
https://dev.mysql.com/doc/refman/8.0/en/alter-table.html, the wording here for 
ALTER TABLE RENAME COLUMN:
   
   >  Views and stored programs that refer to the renamed column. You must 
manually alter the definition of these objects to refer to the new column name. 
   
   seems to suggest the view schema definition is fixed.
   
   I don't know if there is any ANSI definition or other places that specify a 
fixed schema is a requirement for view. Is anyone aware of that?


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