Update sql-migration-guide.md

Author: imback82

docs/sql-migration-guide.md

@@ -338,6 +338,8 @@ license: |
 
   - Since Spark 3.0, `ADD FILE` can be used to add file directories as well. Earlier only single files can be added using this command. To restore the behaviour of earlier versions, set `spark.sql.legacy.addDirectory.recursive` to false.
 
+  - Since Spark 3.0, `SHOW TBLPROPERTIES` on a temporary view will cause `AnalysisException`. In Spark version 2.4 and earlier, it returned an empty result.
+
 ## Upgrading from Spark SQL 2.4 to 2.4.1
 
   - The value of `spark.executor.heartbeatInterval`, when specified without units like "30" rather than "30s", was