Revise message when appending partition with schema mismatch
@@ -375,7 +375,9 @@ public class HiveWriterFactory
HiveType partitionType = existingPartitionColumns.get(i).getType();
if (!tableType.equals(partitionType)) {
throw new PrestoException(HIVE_PARTITION_SCHEMA_MISMATCH, format("" +
- "There is a mismatch between the table and partition schemas. " +
+ "You are trying to write into an existing partition in a table. " +
+ "The table schema has changed since the creation of the partition. " +
+ "Inserting rows into such partition is not supported. " +
"The column '%s' in table '%s' is declared as type '%s', " +
"but partition '%s' declared column '%s' as type '%s'.",
tableColumns.get(i).getName(),
