Overwrite with truncation does not work with column_map

[imrimt]

We have a use case where we want the following:

• We are writing from Spark to Snowflake
• We want to perform overwrite data every time --> SaveMode.Overwrite
• We do NOT want to overwrite the schema --> truncate_table: on because we don't want the table to be dropped (there are grants and shares that we want to keep)
• We want to provide a mapping from the Spark DF's to the Snowflake table columns --> column_map is specified

However, it looks like column_map is not supported in overwrite mode.

How should we go about this use case? It feels like an oversight as truncate_table: on is essentially the same as SaveMode.Append with the additional step of clearing out the data.

We are currently using 2.11.3-spark_3.1 connector.

[imrimt]

In fact, as I typed out the description, I figured out my own workaround:

• Change to SaveMode.Append
• Add an option: "preactions": "TRUNCATE TABLE IF EXISTS %s;"
• No longer needs the option truncate_table

Will close this issue but hopefully it'll be helpful for others who might have similar use cases.