💡
Upgrading delta protocol is an irreversible process. Once upgraded you CANNOT downgrade (default is 1/3), you will need to drop the table and re-create. Always use the lowest protocol required and be sure to test, understand the limitations before upgrading. Check the documentation for details.
```python
%%sql
ALTER TABLE `Global Sales 2` SET TBLPROPERTIES (
'delta.minReaderVersion' = '2',
'delta.minWriterVersion' = '5',
'delta.columnMapping.mode' = 'name'
)
```
Next, we can use `ALETR TABLE` to update the schema :
```python
def rename_columns(table_name="Global Sales 2"):
"""
Renames columns of delta table to remove underscores and use title case.
Either use a rename function or provide your own mapping.
"""
#optional
def rename_column(name):
return name.replace("_"," ").title()
column_mapping = {
"sale_id": "Sale Id",
"product_id": "Product Id",
"customer_id": "Customer Id",
"sale_date": "Sale Date",
"sale_amount": "Sale Amount",
"discount_amount": "Discount Amount",
"tax_amount": "Tax Amount",
"total_amount": "Total Amount",
"store_id": "Store Id",
"sales_rep_id": "SalesRep Id"
}
for old_name, new_name in column_mapping.items():
alter_statement = f"ALTER TABLE `{table_name}` RENAME COLUMN `{old_name}` TO `{new_name}`"
spark.sql(alter_statement)
print(f"Columns in table '{table_name}' have been renamed.")
rename_columns()
```
You can use your own column mapping function. It works in SQL EP as well as in Direct Lake semantic model :
![](https://cdn.hashnode.com/res/hashnode/image/upload/v1727975114506/322aab2a-e399-414b-a7cb-2805b319f05c.png align="center")
💡
If you have any existing downstream items dependent on this delta table, be sure to update them. If you have a Direct Lake model, refresh the schema using Semantic Link/Labs or Tabular Editor or using “Edit Tables” in UI.
## Notes:
*